Evidence about public-health measures

Evidence syntheses on this webpage are organized by:

vaccine safety and efficacy and real-world effectiveness
infection prevention (personal protection like wearing masks, with service limitations that support infection prevention captured in the corresponding government sector on the economic and social responses webpage)
infection control (screening, quarantining, testing, isolation, contact tracing, and susceptibility tracking)
broader public-health measures (risk stratification, outbreak management, and pandemic tracking).

Drugs used as chemoprophylaxis for COVID-19 are addressed on the clinical management webpage, given their benefits accrue only at the individual level (not at the population level, as occurs with vaccinations through herd immunity).

We continue to add evidence syntheses to this webpage as we harvest and process weekly updates from ‘high-yield, high quality’ sources of evidence syntheses and as we add new sources. More details are available about the context for the inventory, our approach to developing and maintain it, and tips for using it. Similar webpages are available for evidence about the clinical management of COVID-19 and related conditions, health-system arrangements, and economic and social responses.

Broad and specific decisions			Criteria for 'best evidence synthesis'			Details to support relevance assessment	Additional decision-relevant details			Citation
Broad and specific decisions			Date of last search	Quality (AMSTAR) rating	Evidence-certainty (e.g., GRADE) assessment available	Key findings	Living evidence synthesis	Type of synthesis	Type of question	Citation
Infection prevention
	Vaccination
		Safety and efficacy of two doses of the same vaccine if two doses are recommended (or a single dose if a single dose is recommended)	2021-10-20	7/9	No	[BioNTech/Pfizer against variants of concern] BioNTech/Pfizer vaccine probably prevents symptomatic infection from the Alpha, Beta Gamma and Delta variants of concern, it probably prevents severe disease, death, and transmission from the Alpha variant of concern, whereas it may prevent symptomatic infection from the Gamma variant of concern, and it may prevent death from the Delta variant of concern	Yes (row content last checked on 2021-10-18)	Rapid review	Benefits and harms	Iorio A, Little J, Linkins L, Abdelkader W, Bennett D, Lavis JN. COVID-19 living evidence synthesis #6 (version 6.21): What is the efficacy and effectiveness of available COVID-19 vaccines in general and specifically for variants of concern? Hamilton: Health Information Research Unit, 6 October 2021.
			2021-10-15	10/11	Yes	[BioNTech/Fosun Pharma/Pfizer vaccine (age-group analysis available)] Compared to placebo, vaccination with BNT162b2 reduces the incidence of symptomatic cases of COVID-19, and probably reduces severe and critical disease substantially, although there remains uncertainty about the effect on mortality; it may increase the incidence of severe adverse events	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	COVID NMA. BNT162b2 vs placebo (BioNTech/Fosun Pharma/Pfizer ). 2020.
			2021-07-12	6/11	Yes	[BioNTech/Pfizer] Vaccination with the Pfizer/BioNTech vaccine reduces the risk of contracting COVID-19 substantially even after the first dose and it probably reduces the risk of severe COVID-19, whereas its effects on other outcomes are yet to be determined; the incidence of serious adverse events may slightly increase, whereas the incidence of any adverse event substantially increase	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Pan American Health Organization. Pfizer-BioNTech COVID-19 vaccine - Efficacy and effectiveness of the vaccine. Pan American Health Organization.; 2021.
			2021-07-12	8/11	Yes	[CanSino] No evidence from phase III randomized controlled trials has been reported to enable an assessment of the safety and efficacy of the CanSino vaccine	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Pan American Health Organization. CanSino COVID-19 vaccine - Efficacy and effectiveness of the vaccine. Pan American Health Organization.; 2021.
			2021-10-15	10/11	Yes	[Coronavac vaccine] Compared to placebo, vaccination with CoronaVac may reduce the incidence of symptomatic cases of COVID-19 by 50%, close to the lowest level deemed effective by the WHO and it may substantially reduce the incidence of severe disease due to COVID-19; the evidence for any difference in serious adverse events is uncertain, although the vaccination probably increases the incidence of any adverse event	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	COVID NMA. Coronavac vs placebo. 2021
			2021-07-12	6/11	Yes	[CoronaVac/Sinovac vaccine] Vaccination with the CoronaVac/Sinovac vaccine reduces the risk of contracting COVID-19 (even after the first dose) and it probably reduces the risk of severe COVID-19, whereas its effects on other outcomes are yet to be determined; the incidence of serious adverse events probably does not increase, whereas the incidence of any adverse event is higher	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Pan American Health Organization. Sinovac COVID-19 vaccine - Efficacy and effectiveness of the vaccine. Pan American Health Organization.; 2021.
			2021-10-20	7/9	No	[CoronaVac/Sinovac vaccine against variants of concern] Coronavac/Sinovac vaccine may prevent infection from the Delta and Gamma variant of concern, it may prevent severe infection from the Delta variant of concern, and it may prevent death from the Gamma variant of concern	Yes (row content last checked on 2021-10-18)	Rapid review	Benefits and harms	Iorio A, Little J, Linkins L, Abdelkader W, Bennett D, Lavis JN. COVID-19 living evidence synthesis #6 (version 6.21): What is the efficacy and effectiveness of available COVID-19 vaccines in general and specifically for variants of concern? Hamilton: Health Information Research Unit, 6 October 2021.
			2021-07-12	6/9	Yes	[Covaxin] No evidence from phase III randomized controlled trials has been reported to enable an assessment of the safety and efficacy of the Covaxin vaccine	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Pan American Health Organization. Bharat Biotech COVID-19 vaccine - Efficacy and effectiveness of the vaccine. Pan American Health Organization.; 2021.
			2021-10-15	10/11	Yes	[EpiVacCorona] The effects of vaccination with EpiVacCorona are uncertain	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	COVID NMA. EPIVACCORONA VS PLACEBO. COVID NMA: Vaccines for COVID-19 patients. 2021.
			2021-07-12	6/9	Yes	[EpiVacCorona] No evidence from phase III randomized controlled trials has been reported to enable an assessment the safety and efficacy of the EpiVacCorona vaccine	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Pan American Health Organization. Vector Institute COVID-19 vaccine - Efficacy and effectiveness of the vaccine. Pan American Health Organization.; 2021.
			2021-10-20	7/9	No	[Gamaleya Research Institute against variants of concern] Gamaleya Research Institute vaccine may prevent ICU admission and death from the Delta variant of concern	Yes (row content last checked on 2021-10-18)	Rapid review	Benefits and harms	Iorio A, Little J, Linkins L, Abdelkader W, Bennett D, Lavis JN. COVID-19 living evidence synthesis #6 (version 6.21): What is the efficacy and effectiveness of available COVID-19 vaccines in general and specifically for variants of concern? Hamilton: Health Information Research Unit, 6 October 2021.
			2021-10-15	10/11	Yes	[Gamaleya Research Institute vaccine] Compared to placebo, vaccination with Gam-COVID-Vac rAd26-S/rAd5-S probably reduces the incidence of symptomatic and severe cases of COVID-19 substantially, although there remains uncertainty about the impact on reducing mortality; the vaccination may not increase the incidence of serious adverse event, but the incidence of any adverse event was not reported	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	COVID NMA. Gam-COVID-Vac rAd26-S/rAd5-S vs Placebo (Gamaleya Research Institute of Epidemiology and Microbiology). 2020.
			2021-07-12	6/11	Yes	[Gamaleya Research Institute vaccine] Vaccination with the Gamaleya vaccine probably reduces the risk of contracting COVID-19 substantially (even after the first dose) and it may reduce the risk of severe COVID-19, whereas its effects on other outcomes are yet to be determined; the incidence of serious adverse events may not be increased	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Pan American Health Organization. Gamaleya COVID-19 vaccine - Efficacy and effectiveness of the vaccine. Pan American Health Organization.; 2021.
			2021-10-20	7/9	No	[Johnson & Johnson against variants of concern] Johnson & Johnson vaccine probably prevents severe disease from the Beta variant of concern and may prevent symptomatic infection from the Delta variant of concern	Yes (row content last checked on 2021-10-18)	Rapid review	Benefits and harms	Iorio A, Little J, Linkins L, Abdelkader W, Bennett D, Lavis JN. COVID-19 living evidence synthesis #6 (version 6.21): What is the efficacy and effectiveness of available COVID-19 vaccines in general and specifically for variants of concern? Hamilton: Health Information Research Unit, 6 October 2021.
			2021-10-15	10/11	Yes	[Johnson & Johnson's Janssen vaccine] Vaccination with AD26.COV2.S probably reduces the incidence of symptomatic cases of COVID-19 by around 67%, and it probably reduces severe disease and mortality, while the incidence of serious adverse events may not increase	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	COVID NMA. Ad26.COV2.S (5×10^10 vp) D0 vs Placebo. 2021.
			2021-07-12	6/11	Yes	[Janssen vaccine] Vaccination with the Janssen vaccine reduces the risk of contracting COVID-19 substantially and reduces the risk of severe COVID-19, whereas its effects on other outcomes are yet to be determined; the vaccination increases the incidence of serious adverse events	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Pan American Health Organization. Janssen COVID-19 vaccine - Efficacy and effectiveness of the vaccine. Pan American Health Organization.; 2021.
			2021-10-20	7/9	No	[Moderna against variants of concern] Moderna vaccine probably prevents infection from the Alpha variant of concern, and it may prevent infection from the Beta, Gamma and Delta variants of concern	Yes (row content last checked on 2021-10-18)	Rapid review	Benefits and harms	Iorio A, Little J, Linkins L, Abdelkader W, Bennett D, Lavis JN. COVID-19 living evidence synthesis #6 (version 6.21): What is the efficacy and effectiveness of available COVID-19 vaccines in general and specifically for variants of concern? Hamilton: Health Information Research Unit, 6 October 2021.
			2021-10-15	10/11	Yes	[ModernaTX vaccine (age-group analysis available)] Compared to placebo, vaccination with mRNA-1273 probably reduces the incidence of symptomatic cases of COVID-19 substantially, and it may reduce severe disease, while the incidence of serious adverse events is probably not increased	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	COVID NMA. mRNA-1273 vs placebo (ModernaTX). 2020.
			2021-07-12	6/11	Yes	[ModernaTX vaccine] Vaccination with the ModernaTX vaccine reduces the risk of contracting COVID-19 substantially (but it may reduce this risk with the first dose) and reduces the risk of severe COVID-19, whereas its effects on other outcomes are yet to be determined; the vaccination probably does not increase the incidence of serious adverse events	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Pan American Health Organization. Moderna COVID-19 vaccine - Efficacy and effectiveness of the vaccine. Pan American Health Organization.; 2021.
			2021-10-20	7/9	No	[Novavax against variants of concern] Novavax vaccine probably prevents infection from the Alpha variant of concern, and it may prevent infection from the Beta variant of concern	Yes (row content last checked on 2021-10-18)	Rapid review	Benefits and harms	Iorio A, Little J, Linkins L, Abdelkader W, Bennett D, Lavis JN. COVID-19 living evidence synthesis #6 (version 6.21): What is the efficacy and effectiveness of available COVID-19 vaccines in general and specifically for variants of concern? Hamilton: Health Information Research Unit, 6 October 2021.
			2021-10-15	10/11	Yes	[Novavax vaccine] The effects of vaccination against COVID-19 with the Novavax vaccine are currently uncertain; it probably slightly increase the risk of any adverse events	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	COVID NMA. NOVAVAX - NVX-COV2373 VS PLACEBO. COVID NMA: Vaccines for COVID-19 patients. 2021.
			2021-07-12	8/11	Yes	[Novavax] Vaccination with Novavax reduces the risk of contracting COVID-19 and probably reduces severe disease	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Pan American Health Organization. Novavax COVID-19 vaccine - Efficacy and effectiveness of the vaccine. Pan American Health Organization.; 2021.
			2021-10-20	7/9	No	[Oxford/AstraZeneca against variants of concern] Oxford/AstraZeneca vaccine probably prevents infection from the Alpha and Delta variants of concern, and it may not prevent infection from the Beta variant of concern; it may prevent ICU admission and death from the Delta variant of concern	Yes (row content last checked on 2021-10-18)	Rapid review	Benefits and harms	Iorio A, Little J, Linkins L, Abdelkader W, Bennett D, Lavis JN. COVID-19 living evidence synthesis #6 (version 6.21): What is the efficacy and effectiveness of available COVID-19 vaccines in general and specifically for variants of concern? Hamilton: Health Information Research Unit, 6 October 2021.
			2021-10-15	10/11	Yes	[Oxford/AstraZeneca vaccine] Compared to vaccinating with MedACWY (meningitis vaccine), vaccination with ChAdOx1 probably reduces the cases of symptomatic SARS-CoV-2 infection, and may reduce severe or critical disease and hospitalisations; the effects on mortality are uncertain, and adverse events are probably less frequent.	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	COVID NMA. ChAdOx1 vs MenACWY (University of Oxford/AstraZeneca ). 2020.
			2021-07-12	6/11	Yes	[Oxford/AstraZeneca] Vaccination with the EU Nodes - Oxford/AstraZeneca vaccine reduces the risk of contracting COVID-19 and may reduce the risk of severe COVID-19, whereas its effects on other outcomes are yet to be determined; the vaccination probably does not increase the overall frequency of serious adverse events	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Pan American Health Organization. EU Nodes-AstraZeneca/ Oxford; AstraZeneca/SK BIO; Serum Institute of India COVID-19 vaccine - Efficacy and effectiveness of the vaccine. Pan American Health Organization.; 2021.
			2021-07-12	7/9	No	[Sinopharm against variants of concern] Sinopharm vaccine may prevent ICU admission and death from the Delta variant of concern	Yes (row content last checked on 2021-10-18)	Rapid review	Benefits and harms	Iorio A, Little J, Linkins L, Abdelkader W, Bennett D, Lavis JN. COVID-19 living evidence synthesis #6 (version 6.21): What is the efficacy and effectiveness of available COVID-19 vaccines in general and specifically for variants of concern? Hamilton: Health Information Research Unit, 6 October 2021.
			2021-10-15	10/11	Yes	[Sinopharm - strain HBO2] Vaccination with Sinopharm HBO2 probably reduces the incidence of symptomatic cases of COVID-19, and it may reduce severe disease, while the incidence of adverse events is probably not increased	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	COVID NMA. SARS-COV-2 STRAIN HBO2 VS PLACEBO. COVID NMA: Vaccines for COVID-19 patients. 2021.
			2021-10-15	10/11	Yes	[Sinopharm - strain WIV04] Vaccination with Sinopharm WIV04 probably reduces the incidence of symptomatic cases of COVID-19, and it may reduce severe disease, while the incidence of adverse events is probably not increased	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	COVID NMA. SARS-COV-2 STRAIN WIV04 VS PLACEBO. COVID NMA: Vaccines for COVID-19 patients. 2021.
			2021-07-12	6/9	Yes	[Sinopharm - WIBP] No evidence from phase III randomized controlled trials has been reported to enable and assessment of the safety and efficacy of the Sinopharm - WIBP vaccine	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Pan American Health Organization. Sinopharm/WIBP COVID-19 vaccine - Efficacy and effectiveness of the vaccine. Pan American Health Organization.; 2021.
			2021-07-12	6/9	Yes	[Zifivax] No evidence from phase III randomized controlled trials has been reported to enable an assessment of the safety and efficacy of the Zifivax vaccine	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Pan American Health Organization. Anhui Zhifei Longcom COVID-19 vaccine - Efficacy and effectiveness of the vaccine. Pan American Health Organization.; 2021.
			2021-02-08	8/11	No	A review exploring factors influencing the efficacy of COVID-19 vaccines found that type of the vaccine technology (e.g., mRNA versus adenovirus), age, sex and the infection rate in the population did not influence vaccine efficacy	No	Full review	Benefits and harms	Calzetta L, Ritondo BL, Coppola A, Matera MG, Di Daniele N, Rogliani P. Factors influencing the efficacy of COVID-19 vaccines: A quantitative synthesis of phase III trials. Vaccines (Basel). 2021;9(4):341.
		Safety and efficacy of one dose of one vaccine and a second dose of a different vaccine (i.e., mix and match or heterologous prime and boost)	2021-10-20	7/9	No	[BioNTech/Pfizer or Moderna to complete vaccination scheme started with Astra Zeneca against variants of concern] Vaccinating with Astra Zeneca followed by BioNTech/Pfizer or Moderna vaccine may prevent symptomatic infection from the Alpha variant of concern	Yes (row content last checked on 2021-10-18)	Rapid review	Benefits and harms	Iorio A, Little J, Linkins L, Abdelkader W, Bennett D, Lavis JN. COVID-19 living evidence synthesis #6 (version 6.21): What is the efficacy and effectiveness of available COVID-19 vaccines in general and specifically for variants of concern? Hamilton: Health Information Research Unit, 6 October 2021.
			2021-08-27	10/11	Yes	[AstraZeneca to complete vaccination scheme started with BioNTech/Pfizer BNT16b2 at 28 days vs two doses of BioNTech/Pfizer BNT16b2 separated by 28 days] Compared to vaccination with two doses of the BNT16b2 vaccine, having a second dose of AstraZeneca after a first dose of BNT16b2 may increase the risk of any adverse event, while the incidence of serious adverse events is uncertain	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	BNT/CHA-28 VS BNT/BNT-28 COVID NMA; 2021.
			2021-08-27	10/11	Yes	[BioNTech/Pfizer BNT162b2 to complete vaccination scheme started with AstraZeneca at 28 days vs two doses AstraZeneca separated by 28 days] Compared to vaccination with two doses of the AstraZeneca vaccine 28 days apart, having a second dose of BNT16b2 after a first dose of AstraZeneca may not increase the risk of any adverse event, while the incidence of serious adverse events is uncertain	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	CHAD/BNT-28 VS CHAD/CHAD-28. COVID NMA; 2021.
		Safety and efficacy of one dose if two doses are recommended	2021-10-20	7/9	No	[Moderna against variants of concern] One dose of Moderna vaccine may prevent symptomatic infection from the Delta variant of concern	Yes (row content last checked on 2021-10-18)	Rapid review	Benefits and harms	Iorio A, Little J, Linkins L, Abdelkader W, Bennett D, Lavis JN. COVID-19 living evidence synthesis #6 (version 6.21): What is the efficacy and effectiveness of available COVID-19 vaccines in general and specifically for variants of concern? Hamilton: Health Information Research Unit, 6 October 2021.
		Safety and efficacy of three doses if two doses were recommended before the emergence of variants
		Effectiveness when administered at large scale	N/A (Protocol)	n/a	Yes	[Protocol - results not yet available] A systematic review evaluating the cost-effectiveness of available SARS-COV-2 vaccines is currently being conducted	No	Protocol	Costs and cost-effectiveness	Rocha-Filho C, Pinto ACP, da Rocha AP, Civile VT, Carvas Junior N, Ramalho GS, et al. Vaccines for preventing SARS-CoV-2 infection: protocol for a rapid systematic review and network meta-analysis with economics evidence. PROSPERO. 2020; CRD42020216544.
			2021-05-11	8/9	No	Evidence shows that age might be a factor that influences the immune response after the first dose of an mRNA-vaccine [Review of studies of low to moderate quality]	Yes (row content last checked on 2021-10-18)	Rapid review	Other	Curran J, Dol J, Boulos L, Somerville M, McCulloch H. Public Health and Health Systems Impacts of SARS-CoV-2 Variants of Concern. Report prepared for the SPOR Evidence Alliance and COVID-END, June 2021.
			2021-05-04	6/9	No	A single or full dose of Astra Zeneca or Pfizer vaccines may prevent household transmission and asymptomatic infection after 14 days of vaccination [Review of experimental and observational studies of variable quality]	Yes (row content last checked on 2021-10-18)	Rapid review	Other	Egunsola O, Mastikhina L, Dowsett LE, Farkas B, Hofmeister M, Saxinger L, Clement FM on behalf of the University of Calgary Health Technology Assessment Unit. Transmissibility of COVID-19 among Vaccinated Individuals: A Rapid Literature Review. May 21, 2021
			N/A (Protocol)	n/a	No	[Protocol - results not yet available] A review exploring the transmission of COVID-19 after vaccination is currently being conducted	Yes (row content last checked on 2021-08-30)	Protocol	Other	Hooper L, Clark R, Pearce-Smith N. Transmission of COVID-19 following COVID-19 vaccination: Protocol for a rapid review. PROSPERO. 2021;CRD42021257125.
		Efficacy/effectiveness by population segment	N/A (Protocol)	n/a	Yes	[Protocol - results not yet available] A systematic review evaluating the differential benefits and harms of available vaccines among different ethnic groups is currently being conducted	No	Protocol	Benefits and harms	Wei GX, Wang H, Song Q, Su W, Li N, Liang Q. The effectiveness, protection rates and adverse outcomes of Pfizer-Biontech's BNT162b2, Moderna's mRNA-1273, and Oxford University / AstraZeneca's ChAdOx1/ AZD1222 vaccines in different ethnic groups:a systematic review and meta-analysis. PROSPERO. 2021;CRD42021234071.
			N/A (Protocol)	n/a	Yes	[Protocol - results not yet available] A review evaluating the safety of COVID-19 candidate vaccines on pregnant women is currently being conducted	No	Protocol	Benefits and harms	Ciapponi A, Bardach A, Comande D, Berrueta M, Mazzoni A, Buekens P. Effects of COVID-19 candidate vaccines or their components on pregnancy safety outcomes. PROSPERO. 2021; CRD42021234185
			N/A (Protocol)	n/a	No	[Protocol - results not yet available] A review exploring the safety and efficacy of COVID-19 vaccines in pregnant, postnatal and breastfeeding women is currently being conducted	Yes (row content last checked on 2021-08-30)	Protocol	Benefits and harms	Fisher J, Chang Y-S, Winn L, Hillman S, Liao S-C, Chien L-Y, et al. COVID-19 vaccination in pregnant, postnatal and breastfeeding women: A living systematic review. PROSPERO. 2021; CRD42021243062
			N/A (Protocol)	n/a	Yes	[Protocol - results not yet available] A review evaluating the efficacy and immunogenicity of COVID-19 vaccines in pregnant and breastfeeding women is currently being conducted	No	Protocol	Benefits and harms	Goncalves AK, Rodrigues HM, Medeiros K, Ferreira Costa AP, Sarmento AC, Aguiar MF et al. Efficacy and immunogenicity of COVID-19 vaccines in pregnant and breastfeeding women and their offspring: a systematic review and meta-analysis protocol. PROSPERO. 2021;CRD42021245360.
			N/A (Protocol)	n/a	Yes	[Protocol - results not yet available] A review evaluating the side effects of COVID-19 vaccines in pregnant and breastfeeding women is currently being conducted	No	Protocol	Benefits and harms	Goncalves AK, Medeiros K, Ferreira Costa AP, Sarmento AC, Rodrigues HM. Side effects of COVID-19 vaccines in pregnant and breastfeeding women: a systematic review/meta-analysis protocol of randomized trials. PROSPERO. 2021;CRD42021243715.
			2021-03-10	4/9	No	Limited evidence suggests that immunocompromised patients could produce an attenuated immune response after being vaccinated against COVID-19 [Review of observational studies of unclear quality]	No	Full review	Benefits and harms	COVID-19 Critical Intelligence Unit. Immunocompromised patients and COVID-19 vaccines. NSW Government. 2021.
			2021-06-21	9/10	Yes	Vaccination in individuals who had a prior COVID-19 infection probably results in a stronger humoral response (e.g., binding and neutralizing antibodies) compared to those with no prior infection; the effects of vaccines on individuals with previous infection on other outcomes are uncertain	Yes (row content last checked on 2021-10-18)	Rapid review	Benefits and harms	National Collaborating Centre for Methods and Tools. What is the effectiveness, immunogenicity and safety of COVID-19 vaccines in persons who have had a prior, confirmed COVID-19 infection? Hamilton, ON: McMaster University; 2021.
			N/A (Protocol)	n/a	No	[Protocol - results not yet available] A review evaluating the efficacy and safety of COVID-19 vaccines on pregnant and breastfeeding women is currently being conducted	Yes (row content last checked on 2021-09-07)	Protocol	Benefits and harms	Low JM & Low YW. Efficacy and safety of COVID-19 vaccine: A systematic review and meta-analysis in pregnant and breastfeeding individuals. PROSPERO. 2021;CRD42021266203.
		Complementary vaccines	2021-03-10	8/11	No	A significant association has been found between influenza vaccination and reduced SARS-CoV-2 infection rate, while no evidence was found regarding the association of influenza vaccination with COVID-19 clinical outcomes [Review of studies of mainly low quality]	No	Full review	Other	Wang R, Liu M, Liu J. The association between influenza vaccination and COVID-19 and its outcomes: A systematic review and meta-analysis of observational studies. Vaccines. 2021;9(5):529.
		Vaccine roll-out (see health-system arrangements)
		Supporting discovery of a vaccine to prevent COVID-19 in general, and for specific population groups
	Personal protection
		Washing hands	2020-04-17	4/9	No	Hand hygiene combined with the use of masks in community settings appears to be more protective against coranaviruses and other infectious respiratory viruses than either approach in isolation	No	Rapid review	Benefits and harms	MacIntyre CR & Chughtai AA. A rapid systematic review of the efficacy of face masks and respirators against coronaviruses and other respiratory transmissible viruses for the community, healthcare workers and sick patients. Int J Nurs Stud. 2020;108:103629.
			2020-04-25	8/11	No	Studies from the pre COVID-19 era show that proper hand-hygiene methods combined with the use of face masks may reduce the rate of influenza-like-illnesses in community settings	No	Full review	Benefit and harms	Aggarwal N, Dwarakanathan V, Gautam N, Ray A. Facemasks for prevention of viral respiratory infections in community settings: A systematic review and meta-analysis. Indian J Public Health. 2020;64(Supplement):S192-S200.
		Wearing masks*	2020-05-03	11/11	Yes	Large reductions in risk of viral infections may be possible with the use of masks, with N95 or similar respirators more likely to lead to greater reductions compared to disposable surgical masks or other reusable masks	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Chu DK, Akl EA, Duda S, et al. Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis [published online ahead of print, 2020 Jun 1]. Lancet. 2020;S0140-6736(20)31142-9. doi:10.1016/S0140-6736(20)31142-9
			2021-07-02	6/10	No	Whereas no research was found on the effectiveness of wearing masks in community settings for COVID-19, studies on SARS and influenza showed that the evidence for wearing masks is stronger in healthcare settings compared to community settings	Yes (row content last checked on 2021-10-18)	Rapid review	Benefits and harms	Chou R, Dana T, Jungbauer R. Update Alert 5: Masks for prevention of respiratory virus infections, including SARS-CoV-2, in health vare and community settings. Annals of Internal Medicine. 2021.
			2020-05-18	7/11	No	Randomized and non-randomized studies from the pre-COVID-19 era show insufficient reporting of data on serious harms of face masks, with discomfort and irritation the only reported downsides	No	Full review	Benefits and harms	Bakhit M, Krzyzaniak N, Scott AM, Clark J, Glasziou P, Del Mar C. Downsides of face masks and possible mitigation strategies: A systematic review and meta-analysis. BMJ Open. 2020;11(2);e044364
			2020-04-30	10/10	Yes	Compared to medical masks, cloth masks may have a lower filtration efficiency and penetration level, and are probably worse for protecting the wearer	No	Full review	Benefits and harms	Santos M, Torres D, Coutinho Cardoso P, Pandis N, Flores-Mir C, Medeiros R, et al. Are cloth masks a substitute to medical masks in reducing transmission and contamination? A systematic review. Brazilian Oral Research. 2020;34:e123.
			N/A (protocol)	n/a	Yes	[Protocol - results not yet available] A systematic review exploring the psychosocial impact of wearing masks in public and the effects on the development of children and adolescents is currently being conducted	No	Protocol	Benefits and harms	Freiberg A, Drossler S, Horvath K, Kampf D, Apfelbacher C, Hahne TM, et al. Impact of wearing face masks in public during the COVID-19 pandemic on the psychosocial effects on development in children and adolescents. PROSPERO. 2020; CRD42020223217
			2020-11-18	9/11	No	Evidence suggests there is a protective effect associated with wearing face masks to prevent the transmission of respiratory diseases, and effectiveness can be improved when combined with other personal protection methods (e.g., hand hygiene) [Review of studies with important heterogeneity among some of their findings and conducted during the COVID-19 pandemic and before]	No	Full review	Benefits and harms	Ollila HM, Partinen M, Koskela J, Savolainen R, Rotkirch A, Laine LT. Face masks to prevent transmission of respiratory diseases: Systematic review and meta-analysis of randomized control trials. medRxiv. 2021. Epub ahead of print.
			2021-03-16	6/10	No	Public-health measures and non-pharmacological interventions (including compulsory mask wearing and community wide masking policies) were effective to mitigate the spread of COVID-19 [Review of studies of low to moderate quality]	No	Full review	Other	Ayouni I, Maatoug J, Dhouib W, Zammit N, Fredj SB, Ghammam R, et al. Effective public health measures to mitigate the spread of COVID-19: A systematic review. BMC Public Health. 2021;21:1015.
		Wearing personal protective equipment	2020-05-03	11/11	Yes	Low certainty evidence suggests N95 respirators and eye protection can lead to a reduction in viral infections	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Chu DK, Akl EA, Duda S, et al. Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis [published online ahead of print, 2020 Jun 1]. Lancet. 2020;S0140-6736(20)31142-9. doi:10.1016/S0140-6736(20)31142-9
		Wearing personal protective equipment	2021-07-02	6/10	No	PPE use by healthcare workers (masks, gloves, gowns and eye protection) has been found to be one of the strongest factors associated with reduced risk of coronavirus infection, with the most consistent associations observed for masks	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Chou R, Dana T, Jungbauer R. Update Alert 5: Masks for prevention of respiratory virus infections, including SARS-CoV-2, in health vare and community settings. Annals of Internal Medicine. 2021.
			2020-04-08	8/10	No	The safety of different decontamination methods for reusing surgical masks in clinical settings is uncertain	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Zorko DJ, Gertsman S, O'Hearn K, et al. DECONTAMINATION INTERVENTIONS FOR THE REUSE OF SURGICAL MASK PERSONAL PROTECTIVE EQUIPMENT: A SYSTEMATIC REVIEW [published online ahead of print, 2020 Jul 9]. J Hosp Infect. 2020;S0195-6701(20)30337-6. doi:10.1016/j.jhin.2020.07.007
			2020-06-01	7/10	Yes	The effectiveness of using powered air-purifying respirators by healthcare workers to prevent risk of infection is uncertain, but they probably improve comfort compared to other respirators	No	Full review	Benefits and harms	Licina A, Silvers A, Stuart RL. Use of powered air-purifying respirator (PAPR) by healthcare workers for preventing highly infectious viral diseases-A systematic review of evidence. Systematic reviews. 2020;9:173.
			2020-03-20	9/10	Yes	The differences between different types of PPE (e.g., attire, gloves, gowns, types of respirators), and levels of protection for preventing exposure to contaminated fluids among healthcare workers is uncertain	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Verbeek J, Rajamaki B, Ijaz S, et al. Personal Protective Equipment for Preventing Highly Infectious Diseases due to Exposure to Contaminated Body Fluids in Healthcare Staff. Cochrane Database Syst Rev 2020;4(4):CD011621.
			2020-03-20	9/10	Yes	The effectiveness of most PPE modifications for preventing exposure to contaminated body fluids in health care workers is uncertain, although easy to doff gowns, and gown-glove improvements may be better than standard gowns and gloves	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Verbeek J, Rajamaki B, Ijaz S, et al. Personal Protective Equipment for Preventing Highly Infectious Diseases due to Exposure to Contaminated Body Fluids in Healthcare Staff. Cochrane Database Syst Rev 2020;4(4):CD011621.
			2020-04-23	6/9	No	Limited evidence suggests that there is a low probability of viral carriage on the surgical masks of healthcare workers treating patients with clinical respiratory illnesses, and no studies about the relationship between carriage and clinical outcomes were identified	No	Full review	Other	Jones P, Roberts S, Hotu C, Kamona S. What proportion of healthcare worker masks carry virus? A systematic review [published online ahead of print, 2020 Jun 24]. Emerg Med Australas. 2020;10.1111/1742-6723.13581. doi:10.1111/1742-6723.13581
			2021-04-24	6/10	No	Using PPE was found to be the strongest factor associated with reducing risk of coronavirus infection among healthcare workers [Review of observational studies]	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Chou R, Dana T, Buckley D, Selph S, Fu R, Totten A. Update alert 9: Epidemiology of and risk factors for coronavirus infection in health care workers. Ann Intern Med 2021; L21-0034.
			2020-05-25	4/9	No	The evidence on extending the use or reuse of PPE is mainly focused on masks, suggesting that extended use of a respirator (N95 or equivalent) is safer than intermittent reuse	Yes (row content last checked on 2021-10-18)	Rapid review	Other	COVID-19 Critical Intelligence Unit. Extended use or reuse of personal protective equipment. St Leonards, NSW: Agency for Clinical Innovation; 2020.
			2020-07-28	4/9	No	No evidence was found evaluating the clinical effectiveness of using face shields in pre-hospital settings	No	Rapid review	Benefits and harms	Kumar D & Spry C. Face shields in pre-hospital settings: Clinical effectiveness and guidelines. Ottawa: Canadian Agency for Drugs and Technologies in Health (CADTH). 2020.
			2020-10-22	8/11	Yes	Whereas wearing any type of mask probably reduces the incidence of respiratory infections, N95 respirators or equivalent were found to be the most effective mask type, compared to surgical, medical and non-medical facemasks	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Kim MS, Seong D, Li H, Chun SK, Park Y, Lee M, et al. Comparative efficacy of N95, surgical, medical, and non-medical facemasks in protection of respiratory virus infection: A living systematic review and network meta-analysis (preprint). The Lancet. 2021.
			2020-12-27	9/11	No	A high proportion of adverse events (mainly, but not limited to skin problems) has been reported among healthcare workers using personal protective equipment [Review of observational studies of low to moderate quality]	No	Full review	Other	Galanis PA, Vraka I, Fragkou D, Bilali A, Kaitelidou D. Impact of personal protective equipment use on health care workers physical health during the COVID-19 pandemic: A systematic review and meta-analysis. American Journal of Infection Control. 2021.
			2020-08-04	5/9	No	Medical staff could be at risk of developing pressure injuries while wearing protective equipment for long periods of time to prevent COVID-19 infection [Review of observational studies]	No	Full review	Other	Yu J-N, Wu B-B, Feng L-P, Chen H-L. COVID-19 related pressure injuries in patients and personnel: A systematic review. Journal of Tissue Viability. 2021.
			2021-05-11	8/9	No	No robust evidence was found on adjusting personal protective equipment procedures for health workers in response to the spread of variants of concern	Yes (row content last checked on 2021-10-18)	Rapid review	Other	Curran J, Dol J, Boulos L, Somerville M, McCulloch H. Public Health and Health Systems Impacts of SARS-CoV-2 Variants of Concern. Report prepared for the SPOR Evidence Alliance and COVID-END, June 2021.
		Disinfecting surfaces and facilities	2020-04-24	5/9	No	Temperature and humidity appear to have an important effect on how long SARS-CoV-2 can live on surfaces (from a few hours up to 28 days), and alcohol-based hand rub formulations recommended by WHO are an efficient disinfectatnt agent for surfaces [Review of studies of unknown quality]	No	Full review	Other	Noorimotlagh Z, Mirzaee SA, Jaafarzadeh N, Maleki M, Kalvandi G, Karami C. A systematic review of emerging human coronavirus (SARS-CoV-2) outbreak: Focus on disinfection methods, environmental survival, and control and prevention strategies. Environmental Science and Pollution Research. 2020.
			2020-12-31	8/9	No	Although they may not be viable, fragments of SARS-CoV-2 can probably be detected on surfaces in community settings for up to seven days; cleaning and disinfecting procedures probably decrease or eliminate SARS-CoV-2 fragments	Yes (row content last checked on 2021-10-18)	Rapid review	Other	National Collaborating Centre for Methods and Tools. Rapid Review Update 1: What is known about how long the virus can survive with potential for infection on surfaces found in community settings? Hamilton, ON: National Collaborating Centre for Methods and Tools; 2021.
			2020-07-10	5/10	No	Not enough evidence exists to determine survivability on various surfaces and optimal disinfection methods for these surfaces, or about fomite transmissibility of SARS-CoV-2	Yes (row content last checked on 2021-10-18)	Full review	Other	Bedrosian N, Mitchell E, Rohm E, Rothe M, Kelly C, String G, et al. A systematic review of surface contamination, stability, and disinfection data on SARS-CoV-2 (Through July 10, 2020). Environmental Science Technology. 2020.
			2020-05-27	5/9	No	Environmental disenfection may result in viral inactivation on surfaces [Review of mainly laboratory studies of unknown quality]	No	Rapid review	Other	Shimabukuro PMS, Duarte ML, Imoto AM, Atallah AN, Franco ESB, Peccin MS, et al. Environmental cleaning to prevent COVID-19 infection: A rapid systematic review. Sao Paulo Medical Journal. 2020.
			2020-05-21	8/10	No	A review exploring the factors influencing the extent of indoor transmission of COVID-19 found microbiological evidence showing that transmission occurred mostly through respiratory droplets released through the air or touching contaminated surfaces, whereas no robust evidence wad found to confirm aerosol transmission despite it being possible [Review of studies of variable quality]	No	Rapid review	Other	Goodwin L, Hayward T, Krishan P, Nolan G, Nundy M, Ostrishko K et al. Which factors influence the extent of indoor transmission of SARS-CoV-2? A rapid evidence review. J Glob Health. 2021;11:10002.
		Physical distancing	2020-05-03	11/11	Yes	Physical distancing of more than one metre probably results in a large reduction in risk of viral infections	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Chu DK, Akl EA, Duda S, et al. Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis [published online ahead of print, 2020 Jun 1]. Lancet. 2020;S0140-6736(20)31142-9. doi:10.1016/S0140-6736(20)31142-9
			2020-07-29	8/11	No	Global prevalence of depression and anxiety during the COVID-19 pandemic have been estimated to be 24% and 21% respectively, representing a concurrent epidemic, with public transportation closures the only mitigation measure found to be associated with increased anxiety	No	Full review	Other	Castaldelli-Maia JM, Marziali ME, Lu Z, Martins SS. Investigating the effect of national government physical distancing measures on depression and anxiety during the COVID-19 pandemic through meta-analysis and meta-regression. Psychological Medicine. 2020;51(6)
			2020-07-01	5/9	No	When economic evaluations model a long time horizon, social distancing measures were found to be more cost-effective than quarantine, non-intervention, or herd immunity	No	Full review	Costs and cost-effectiveness	Rezapour A, Souresrafil A, Peighambari MM, Heidarali M, Tashakori-Miyanroudi M. Economic evaluation studies of programs against COVID-19: A systematic review of the literature. International Journal of Surgery. 2020;85:10-18.
			N/A (Protocol)	n/a	No	[Protocol - results not yet available] A review evaluating the cost-effectiveness of public health interventions, including social distancing, is currently being conducted	No	Protocol	Costs and cost-effectiveness	Rayanakorn A, Chaiprom P, Lee SWH. Cost-effectiveness of public health interventions on COVID-19 control: A systematic review and meta-analysis. PROSPERO. 2021; CRD42021243848
			2021-05-11	8/9	No	Evidence shows that physical distancing and other non-pharmaceutical interventions are important to reduce the spread and impact of variants of concern in the community [Review of studies of low to moderate quality]	Yes (row content last checked on 2021-10-18)	Rapid review	Other	Curran J, Dol J, Boulos L, Somerville M, McCulloch H. Public Health and Health Systems Impacts of SARS-CoV-2 Variants of Concern. Report prepared for the SPOR Evidence Alliance and COVID-END, June 2021.
		Temporal distancing
		Altering sexual activities	N/A (Protocol)	n/a	No	[Protocol - results not yet available] A systematic review to evaluate whether SARS-CoV-2 can be sexually transmitted is currently being conducted	Yes (row content last checked on 2021-08-30)	Protocol	Other	Duarte G, Ortiz-Muñoz L, Morales M, Rada G. Sexual Transmission of SARS-CoV-2 Virus, and its Role in the Spread of COVID-19: a Living Systematic Review Protocol. PROSPERO 2020; CRD42020189368.
			N/A (Protocol)	n/a	No	[Protocol - results not yet available] A review evaluating SARS-CoV-2 viral shedding in fluids involved in the sex act is currently being conducted	Yes (row content last checked on 2021-08-30)	Protocol	Other	Gonsalves L, Kara E, Broutet N, de Leon RGP, Cala DC, Peña CGM, et al. Viral shedding of SARS-CoV-2 in bodily fluids involved in the sex act: A living systematic review. PROSPERO. 2020; CRD42020204741.
		Public-focused behaviour-change supports	2020-05-01	6/11	No	People touch their faces as often as 50 times per hour, and their T-zone (eyes, nose, mouth and chin) as much as 68 times per hour, which requires extensive behaviour intervention and community awareness [Review of observational studies]	No	Full review	Other	Rahman J. Mumin J. Fakhruddin B. How frequently do we touch facial T-zone: A systematic review. 2020;86(1):75.
			2021-02-12	7/10	No	A review of communication strategies to mitigate risk behaviours found low to moderate evidence suggesting clear, action-oriented and tailored messages that are repeated frequently and delivered by trusted leaders probably improve risk communication, and that addressing uncertainty and previous errors in communication may help to build trust, while framing messages positively in relation to collective action rather than individual action is probably more effective	Yes (row content last checked on 2021-10-18)	Rapid review	Benefits and harms	National Collaborating Centre for Methods and Tools. Rapid Review Update 1: What are best practices for risk communication and strategies to mitigate risk behaviours? National Collaborating Centre for Methods and Tools. 2021;
			N/A (protocol)	n/a	Yes	[Protocol - results not yet available] A systematic review assessing barriers and facilitators to population-wide adherence to infection prevention and control measures is currently being conducted	No	Protocol	Other	Mendonca K, Jacome A, Silva B, Patino C, Chaves G, Alchieri JC et al. Barriers and facilitators to populational adherence to prevention and control measures of COVID-19 and other respiratory infectious diseases: a rapid qualitative evidence synthesis. PROSPERO. 2020;CRD42020205750.
			2021-03-12	6/9	No	Evidence suggests that non-pharmaceutical interventions for reducing COVID-19 appear to be more effective when used as a combination of multiple measures (social distancing, isolation and quarantine, and workplace distancing); a number of major enablers and barriers that impact the effectiveness of these interventions have been identified [Review of observational studies mainly of low quality]	No	Full review	Other	Regmi K & Lwin CM. Factors associated with the Implementation of non-pharmaceutical interventions for reducing coronavirus disease 2019 (COVID-19): A systematic review. International Journal of Environmental Research and Public Health. 2021;18(8):4274.
			2020-10-01	6/11	No	High levels of knowledge about COVID-19 has been found in sub-Saharan Africa, but important gaps in attitudes, perceptions and preventative practices towards COVID-19 remain [Review of studies of moderate to high quality]	No	Full review	Views and experiences	Nwagbara UI, Osual EC, Chireshe R, Bolarinwa OA, Saeed BQ, Khuzwayo N, et al. Knowledge, attitude, perception, and preventative practices towards COVID-19 in sub-Saharan Africa: A scoping review. PLoS One. 2021;16(4):e0249853.
			2021-05-26	8/10	No	Evidence shows that digital interventions may facilitate improvements in behaviours that promote community hygiene (especially hand washing) [Review of studies of variable quality conducted during the COVID-19 pandemic and before]	No	Rapid review	Benefits and harms	Gold N, Hu XY, Denford S, Xia RY, Towler L, Groot J, et al. Effectiveness of digital interventions to improve household and community infection prevention and control behaviours and to reduce incidence of respiratory and/or gastro-intestinal infections: A rapid systematic review. BMC Public Health. 2021;21:1180.
		Health worker and essential worker-focused behaviour change supports for the above	2020-03-26	7/9	Yes	The design and content of infection prevention and control guidelines, how they are communicated, and whether there is adequate organizational support, training, and access to personal protective equipment affects adherence among healthcare workers	No	Rapid review	Other	Houghton C, Meskell P, Delaney H, et al. Barriers and Facilitators to Healthcare Workers' Adherence with Infection Prevention and Control (IPC) Guidelines for Respiratory Infectious Diseases: a Rapid Qualitative Evidence Synthesis. Cochrane Database Syst Rev 2020;4(4):CD013582.
			2020-03-20	9/10	Yes	There is uncertainty about the effectiveness of procedures to prevent exposure to contaminated body fluids in health care workers, although providing donning and doffing instructions as well as using extra sanitation for doffing may reduce the risk of contamination	Yes (row content last checked on 2021-10-18)	Full review	Benefits and harms	Verbeek J, Rajamaki B, Ijaz S, et al. Personal Protective Equipment for Preventing Highly Infectious Diseases due to Exposure to Contaminated Body Fluids in Healthcare Staff. Cochrane Database Syst Rev 2020;4(4):CD011621.
			2020-11-03	7/9	Yes	The risks of dispersion or aerosol generation and infection transmission with nasopharyngeal and oropharyngeal swabs are uncertain	No	Full review	Other	Agarwal A, Fernando SM, Honarmand K, Bakaa L, Brar S, Granton D, Chaudhuri D, Chetan D, Hu M, Basmaji J, Muttalib F, Rochwerg B, Adhikari NKJ, Lamontagne F, Murthy S, Hui DS, Gomersall CD, Mubareka S, Diaz J, Burns KE, Couban R, Vandvik PO. Risk of dispersion or aerosol generation and infection transmission with nasopharyngeal and oropharyngeal swabs for detection of COVID-19: a systematic review. BMJ Open. 2021 Mar 17;11(3):e040616.
			2020-12-01	5/9	No	The risks of of transmitting COVID-19 during nebulizer treatments are uncertain [Review of studies of mainly low quality conducted during the COVID-19, influenza, MERS and SARS outbreaks]	Yes (row content last checked on 2021-10-18)	Rapid review	Other	Goldstein KM, Ghadimi K, Mystakelis H, Kong Y, Meng T, Cantrell S, Von Isenburg M, Gordon A, Ear B, Gierisch JM, Williams JW. RIsk of transmitting COVID-19 during nebulizer treatment: A living ultra-rapid review (September 2020 update). 2020.
		Other	2020-07-21	6/6	Yes	No completed studies were found that evaluated the effects of healthcare workers' use of antimicrobial mouthwash and nasal sprays to protect them when treating suspected COVID-19 patients	No	Full review	Benefits and harms	Burton MJ, Clarkson JE, Goulao B, Glenny A-M, McBain AJ, Schilder AGM, et al. Use of antimicrobial mouthwashes (gargling) and nasal sprays by healthcare workers to protect them when treating patients with suspected or confirmed COVID‐19 infection. Cochrane Database of Systematic Reviews. 2020;(9):Art. No.: CD013626. DOI: 10.1002/14651858.CD013626.pub2.
			2020-06-01	6/6	Yes	No completed studies were found that evaluated the effects of healthcare workers' use of antimicrobial mouthwash and nasal sprays to protect them when undertaking aerosol-generating procedures on suspected COVID-19 patients	No	Full review	Benefits and harms	Burton MJ, Clarkson JE, Goulao B, Glenny A-M, McBain AJ, Schilder AGM, et al. Antimicrobial mouthwashes (gargling) and nasal sprays to protect healthcare workers when undertaking aerosol‐generating procedures (AGPs) on patients without suspected or confirmed COVID‐19 infection. Cochrane Database of Systematic Reviews. 2020;(9):Art. No.: CD013628. DOI: 10.1002/14651858.CD013628.pub2.
			2021-02-01	7/10	No	Although no evidence has demonstrated a reduction of COVID-19 transmission using mouthwashes, rinsing with a solution 1% PVP-I or Listerine has shown to reduce the viral load [Review of observational studies of moderate quality]	No	Full review	Benefits and harms	Mohebbi ZS, Ebrahimi T, Shamshiri AR. Do mouthwashes reduce covid-19 viral load during dental procedures and oropharyngeal examinations? A systematic review. Preprints. 2021.
			N/A (Protocol)	n/a	Yes	[Protocol - results not yet available] A review evaluating the effects of mouth-rinses on the viral load of SARS-CoV-2 in saliva is currently being conducted	Yes (row content last checked on 2021-08-30)	Protocol	Benefits and harms	Vásquez AAH, Barrenechea-Pulache A, Comandé D, Azañedo D. Effect of mouth-rinses on viral load of SARS-CoV-2 in saliva: A living systematic review and meta-analysis. PROSPERO. 2021; CRD42021240561
			N/A (Protocol)	n/a	Yes	[Protocol - results not yet available] A review evaluating the efficacy of routine glove use by the general healthy population to prevent COVID-19 is currently being conducted	Yes (row content last checked on 2021-08-30)	Protocol	Benefits and harms	Morales MB, Ortiz-Muñoz L, Duarte Anselmi G, Rada G; COVID‐19 L·OVE Working Group. Use of gloves for the prevention of COVID-19 in healthy population: A living systematic review protocol. Health Science Reports. 2021 Mar 9;4(2):e255.
			2020-08-01	5/9	No	Whereas no evidence was found to support the effectiveness of portable air filters for reducing the incidence of respiratory infections, two studies showed that they are capable of capturing or removing airborne bacteria in indoor settings [Review of observational studies of moderate quality]	No	Full review	Benefits and harms	Hammond A, Khalid T, Thornton HV, Woodall CA, Hay AD. Should homes and workplaces purchase portable air filters to reduce the transmission of SARS-CoV-2 and other respiratory infections? A systematic review. PLoS One. 2021;16(4):e0251049.
			2021-01-14	7/10	No	Evidence has shown that HEPA purifiers are the most efficient filters to decontaminate the air from particles in the range of sizes relevant to SARS-CoV-2 [Review of observational studies of unknown quality]	No	Full review	Benefits and harms	Liu DT, Philips KM, Speth MM, Besser G, Mueller CA, Sedaghat AR. Portable HEPA purifiers to eliminate airborne SARS-CoV-2: A systematic review. Otolaryngology - Head and Neck Surgery. 2021.
	Service limitations (see relevant sector within economic and social responses)
Infection control
	Screening
		Targets	2020-05-01	7/9	No	Study design, quality, and prevalence estimates of early SARS-CoV-2 serosurveys are heterogeneous (ranging from 0.4% to 59.3%), suggesting that the urgency to examine seroprevalence may have compromised methodological rigour	Yes (row content last checked on 2021-10-18)	Rapid review	Other	Bobrovitz N, Arora R, Yan T, Rahim H, Duarte N, Bouher E, et al. Lessons from a Rapid Systematic Review of Early SARS-CoV-2 Serosurveys. MedRxiv 2020.
			2020-07-15	8/10	No	Evidence of signs or symptoms that can be used to determine if patients presenting to primary care or outpatient settings have COVID-19 is currently uncertain, but the presence of anosmia or ageusia may be useful as a red flag for COVID-19 and the presence of fever or cough, given their high sensitivities, may also be useful to identify people for further testing	No	Full review	Other	Struyf T, Deeks JJ, Dinnes J, et al. Signs and symptoms to determine if a patient presenting in primary care or hospital outpatient settings has COVID-19 disease. Cochrane Database Syst Rev. 2020;7:CD013665. Published 2020 Jul 7. doi:10.1002/14651858.CD013665
			2020-07-03	7/10	No	Despite substantial variation on the secondary attack rates, asymptomatic individuals were responsible for fewer secondary infections compared to symptomatic and pre-symptomatic individuals	Yes (row content last checked on 2021-10-18)	Full review	Other	Qui X, Nergiz AI, Maraolo AE, Bogoch II, Low N, Cevik M. The role of asymptomatic and pre-symptomatic infection in SARS-CoV-2 transmission - A living systematic review. Clinical Microbiology and Infection. 2021;27(4):551-519.
			2020-06-10	7/11	No	On average 20% of patients with SARS-CoV-2 remain asymptomatic through the course of infection, and these infections may have lower secondary attack rates compared to symptomatic infections and there is variability in the rate of presymptomatic infections [Review of observational studies]	Yes (row content last checked on 2021-10-18)	Full review	Other	Buitrago-Garcia D, Egli-Gany D, Counotte MJ, Hossmann S, Imeri H, Ipekci AM, et al. Occurrence and transmission potential of asymptomatic and presymptomatic SARS-CoV-2 infections: A living systematic review and meta-analysis. PLoS Medicine. 2020;17(9):e1003346.
			2020-04-17	6/10	Yes	While no evidence was found on universal screening for SARS-CoV-2 infection, modelling studies suggest that screening at travel hubs may slightly slow the importation of infected cases	No	Rapid review	Benefits and harms	Viswanathan M, Kahwati L, Jahn B, Giger K, Dobrescu AI, Hill C, et al. Universal screening for SARS‐CoV‐2 infection: A rapid review. Cochrane Database of Systematic Reviews 2020, Issue 9. Art. No.: CD013718. DOI: 10.1002/14651858.CD013718.
			2020-08-25	8/11	No	A meta-analysis found that 23% of confirmed SARS-CoV-2 infections are asymptomatic, but this varies depending on the setting in which the infections occur [Review of observational studies with important heterogeneity]	No	Rapid review	Benefits and harms	Beale S, Hayward A, Shallcross L, Aldridge RW, Fragaszy E. A rapid review and meta-analysis of the asymptomatic proportion of PCR-confirmed SARS-CoV-2 infections in community settings. Wellcome Open Research. 2020;5:266.
			2020-06-08	7/10	No	Limited evidence suggests that mass testing combined with lockdowns might be an effective strategy to control COVID-19, compared to lockdown alone [Review of observational and modelling studies]	No	Full review	Benefits and harms	Johanna N, Citrawijaya H, Wangge G. Mass screening vs lockdown vs combination of both to control COVID-19: A systematic review. Journal of Public Health Research. 2020;9(4):2011.
			2020-05-07	8/11	No	It is estimated that COVID-19 asymptomatic cases are more common in children and healthcare workers compared to the general population [Review of studies of variable quality and substantial heterogeneity]	No	Full review	Benefits and harms	Chen C, Zhu C, Yan D, Liu H, Li D, Zhou Y, et al. The epidemiological and radiographical characteristics of asymptomatic infections with the novel coronavirus (covid-19): A systematic review and meta-analysis. International Journal of Infectious Diseases. 2021.
			2020-06-21	4/9	No	The limited evidence available assessing the role of children in the transmission of SARS-CoV-2 suggests that children are unlikely to play an important role in overall transmission [Review of studies of unknown quality]	Yes (row content last checked on 2021-10-18)	Rapid review	Other	Li X, Xu W, Dozier M, He Y, Kirolos A, Lang Z, et al. The role of children in the transmission of SARS-CoV2: Updated rapid review. Journal of Global Health. 2020;10(2):021101.
			2021-06-14	6/10	No	COVID-19 screening among vaccinated or partially vaccinated populations has been most commonly conducted using PCR complemented with rapid antigen tests [Review of studies of unclear quality]	No	Rapid review	Other	Egunsola O, Farkas B, Flanagan J, Salmon C, Mastikhina L, Clement FM on behalf of the University of Calgary Health Technology Assessment Unit. Surveillance of COVID-19 in a Vaccinated Population: A Rapid Literature Review. Spor Evidence Alliance. 2021.
		Methods	2020-04-30	9/11	No	Children over 12 months of age generally experience milder symptoms than adults, but younger children were more likely to experience critical illness and vomiting [Review of observational studies]	No	Full review	Other	Cui X, Zhao Z, Zhang T, Guo W, Guo W, Zheng J, et al. A systematic review and meta-analysis of children with coronavirus 2019 (COVID-19). Journal of medical virology. 2020.
			2020-05-29	9/11	No	Non-contact infrared thermometers and thermal scanners may have reasonable sensitivity and specificity for diagnosing fever, but the sensitivity of thermal scanners decreased in the context of pandemics [Review of studies conducted during the COVID-19, H1N1, seasonal influenza and SARS outbreaks]	No	Full review	Test accuracy	Aggarwal N, Garg M, Dwarakanathan V, Gautam N, Kumar SS, Jadon RS, et al. Diagnostic accuracy of non-contact infrared thermometers and thermal scanners: A systematic review and meta-analysis. Journal of Travel Medicine. 2020.
			2020-04-17	6/10	Yes	The certainty of the evidence is low or very low for the accuracy of different universal screening methods, but in general they are shown to have low sensitivity	No	Rapid review	Test accuracy	Viswanathan M, Kahwati L, Jahn B, Giger K, Dobrescu AI, Hill C, et al. Universal screening for SARS‐CoV‐2 infection: A rapid review. Cochrane Database of Systematic Reviews 2020, Issue 9. Art. No.: CD013718. DOI: 10.1002/14651858.CD013718.
			2020-07-01	5/9	No	Economic evaluations show that screening programs may be a cost-effective strategy to control COVID-19	No	Full review	Costs and cost-effectiveness	Rezapour A, Souresrafil A, Peighambari MM, Heidarali M, Tashakori-Miyanroudi M. Economic evaluation studies of programs against COVID-19: A systematic review of the literature. International Journal of Surgery. 2020;85:10-18.
			2020-05-01	9/11	No	Fever, cough, myalgia and dyspnea were found to be the most common symptoms among COVID-19 patients [Review of studies of variable quality and substantial heterogeneity]	No	Full review	Other	Jafari A, Falahatkar S, Yekta K, Mohammad H. COVID-19 clinical characteristics, complications and comorbidity: An updated systemic review and meta-analysis. The Lancet. 2020.
			2021-01-08	8/11	No	COVID-19 in children is usually associated with a favourable clinical course although severe disease and death do occur, the latter more commonly in hospitalised children in low and middle income compared with high income countries; the most prevalent clinical manifestations are fever and cough [Review of studies of variable quality]	No	Full review	Other	Irfan O, Muttalib F, Tang K, Jiang L, Lassi ZS, Bhutta Z. Clinical characteristics, treatment and outcomes of paediatric COVID-19: A systematic review and meta-analysis. Archives of Disease in Childhood. 2021:archdischild-2020-321385.
		Locations (and frequency if applicable)	2020-11-13	9/10	Yes	This rapid review found insufficient real-world evidence to determine the effects of travel related measures to contain the COVID-19 pandemic, although some studies from the pre-COVID era found screening at borders as a possible approach for detecting infected travellers	Yes (row content last checked on 2021-10-18)	Rapid review	Benefits and harms	Burns J, Movsisyan A, Stratil JM, Coenen M, Emmert-Fees KMF, Geffert K, et al. Travel‐related control measures to contain the COVID‐19 pandemic: A rapid review. Cochrane Database of Systematic Reviews.2020;(9):Art. No.: CD013717. DOI: 10.1002/14651858.CD013717.
			2020-05-22	4/10	No	Insufficient evidence to assess the effectiveness of workplace screening programs for reducing the spread of COVID-19 was found in healthcare settings, but some evidence suggests that multifaceted strategies are most likely to be effective in detecting staff illness [Review of studies mainly conducted during the pre-COVID-19 era]	No	Rapid review	Benefits and harms	Erdmann R. Rapid review: Effectiveness of workplace screening programs for reducing the spread of COVID-19 in healthcare settings. Edmonton, AB: Alberta Health Services, COVID-19 Scientific Advisory Group; 2020.
			2020-07-27	9/11	No	While mass testing of residents and staff as well as guidance on infection prevention and control measures were frequently implemented in long-term care facilities, their effects are uncertain [Review mainly based on observational studies of low quality]	No	Rapid review	Other	Frazer K, Mitchell L, Stokes D, Lacey E, Crowley E, Kelleher C. A rapid systematic review of measures to protect older people in long term care facilities from COVID-19. medRxiv. 2020.
			2021-05-11	8/9	No	Evidence shows that high transmission of variants of concern in the same household is concerning, warrantining the use of non-pharmaceutical public health measures alongside a vaccine rollout strategy [Review of studies of low to moderate quality]	Yes (row content last checked on 2021-10-18)	Rapid review	Other	Curran J, Dol J, Boulos L, Somerville M, McCulloch H. Public Health and Health Systems Impacts of SARS-CoV-2 Variants of Concern. Report prepared for the SPOR Evidence Alliance and COVID-END, June 2021.
	Quarantining of exposed or potentially exposed individuals
		Voluntary or imposed	2020-04-01	9/11	No	One randomized controlled trial has found that quarantining workers during an epidemic when members of their household are infected can control the spread of influenza-like-illness, but increases their individual risk of infection	No	Full review	Benefits and harms	Jefferson T, Jones M, Al Ansari L, Bawazeer G, Beller E, Clark J, et al. Physical Interventions to Interrupt or Reduce the Spread of Respiratory Viruses. Part I - Face Masks, Eye Protection and Person Distancing: Systematic Review and Meta-Analysis. MedRxiv 2020.
			2020-06-23	7/10	Yes	Evidence of how effective quarantines are alone or in combination with other measures for people who were in contact with a confirmed/suspected case of COVID-19 mostly comes from mathematical modelling studies, which consistently show that they can be important for reducing COVID-19 incidence and mortality	Yes (row content last checked on 2021-10-18)	Rapid review	Other	Nussbaumer-Streit B, Mayr V, Dobrescu AIulia, Chapman A, Persad E, Klerings I, et al. Quarantine alone or in combination with other public health measures to control COVID‐19: A rapid review. Cochrane Database of Systematic Reviews. 2020;(4)CD013574.
			2020-11-13	9/10	Yes	The effectiveness of quarantining travellers is uncertain	Yes (row content last checked on 2021-10-18)	Rapid review	Benefits and harms	Burns J, Movsisyan A, Stratil JM, Coenen M, Emmert-Fees KMF, Geffert K, et al. Travel‐related control measures to contain the COVID‐19 pandemic: A rapid review. Cochrane Database of Systematic Reviews.2020;(9):Art. No.: CD013717. DOI: 10.1002/14651858.CD013717.
			2020-06-02	5/9	No	Whereas the majority of jurisdictions explored require a 14-day quarantine for people exposed to COVID-19, there is important variability in the duration of quarantine from symptoms onset, and after having ended symptoms	No	Full review	Other	National Collaborating Centre for Methods and Tools. Rapid Review: Are any jurisdictions using isolation periods other than 14 days in response to COVID-19?. Hamilton, ON: National Collaborating Centre for Methods and Tools; 2020.
			2020-05-01	9/11	No	The average incubation period of patients with COVID-19 has been estimated to be five days, while the duration of illness to dyspnea, onset of symptoms to hospital admission, hospital admission to ICU admission, and first symptom to death occurred in an average of 13, six, five and 17 days, respectively [Review of studies of variable quality and substantial heterogeneity]	No	Full review	Other	Jafari A, Falahatkar S, Yekta K, Mohammad H. COVID-19 clinical characteristics, complications and comorbidity: An updated systemic review and meta-analysis. The Lancet. 2020.
			N/A (Protocol)	n/a	No	[Protocol - results not yet available] A review evaluating the cost-effectiveness of public health interventions, including quarantines, is currently being conducted	No	Protocol	Costs and cost-effectiveness	Rayanakorn A, Chaiprom P, Lee SWH. Cost-effectiveness of public health interventions on COVID-19 control: A systematic review and meta-analysis. PROSPERO. 2021; CRD42021243848
			2021-03-12	6/9	No	Evidence suggests that non-pharmaceutical interventions for reducing COVID-19 appear to be more effective when used as a combination of multiple measures (social distancing, isolation and quarantine, and workplace distancing); a number of major enablers and barriers that impact the effectiveness of these interventions have been identified [Review of observational studies mainly of low quality]	No	Full review	Other	Regmi K & Lwin CM. Factors associated with the Implementation of non-pharmaceutical interventions for reducing coronavirus disease 2019 (COVID-19): A systematic review. International Journal of Environmental Research and Public Health. 2021;18(8):4274.
			2021-05-11	8/9	No	Evidence shows that non-pharmaceutical interventions (including lockdowns and quarantines) appear to be required to limit transmission during vaccine rollout to reduce the spread of variants of concern; data on the prevalence and incidence of variants of concern is needed to make decisions about quarantining travellers [Review of studies of low to moderate quality]	Yes (row content last checked on 2021-10-18)	Rapid review	Other	Curran J, Dol J, Boulos L, Somerville M, McCulloch H. Public Health and Health Systems Impacts of SARS-CoV-2 Variants of Concern. Report prepared for the SPOR Evidence Alliance and COVID-END, June 2021.
	Testing
		Optimizing testing across different types of individuals, settings and timing options	2020-05-01	6/11	No	The incidence of positive RT-PCR and abnormal computed tomography tests were higher than 92% among pregnant women with SARS-CoV-2 infection, and fever and cough were the most common symptoms	No	Full review	Other	Uygun-Can B & Acar-Bolat B. Clinical properties and diagnostic methods of COVID-19 infection in pregnancies: Meta-analysis. BioMed Research International. 2020.
			2020-04-24	7/9	No	In patients with COVID-19, RT-PCR was found to have higher positivity rates in the early days after symptom onset, whereas sampling 10 days after symptom onset appears to substantially reduce positivity rates [Review of studies of low quality]	No	Full review	Test accuracy	Mallett S, Allen AJ, Graziadio S, Taylor SA, Sakai NS, Green K, et al. At what times during infection is SARS-CoV-2 detectable and no longer detectable using RT-PCR-based tests? A systematic review of individual participant data. BMC Medicine. 2020;18(1):346.
			2020-05-01	6/10	No	Drive-through testing was one of the most common approaches implemented for population testing for SARS-CoV-2 [Review of observational studies of unkown quality]	No	Full review	Other	Foster CR, Campbell F, Blank L, Cantrell A, Black M, Lee ACK. A scoping review of the experience of implementing population testing for SARS-CoV-2. medRxiv. 2021.
			2020-09-29	6/9	No	The communicable period of SARS-CoV-2 was found to potentially exceed the time of positive detection of viral nucleic acid by RT-PCR testing [Review of studies of variable quality and substantial heterogeneity among their findings]	No	Rapid review	Other	Park M, Pawliuk C, Nguyen T, Griffitt A, Dix-Cooper L, Fourik N, et al. Determining the communicable period of SARS-CoV-2: A rapid review of the literature, March to September 2020. Eurosurveillance. 2021;26(14):2001506
			2020-08-11	6/11	No	Evidence shows similar secondary attack rates among children and adults, while children seem to be less frequently infected with SARS-CoV-2 [Review of studies of unknown quality with significant heterogeneity among their findings]	No	Full review	Other	Spielberger BD, Goerne T, Geweniger A, Henneke P, Elling R. Intra-household and close-contact SARS-CoV-2 transmission among children – A systematic review. Frontiers in Pediatrics. 2021;9:613292.
			2021-06-15	7/9	No	Limited evidence is available on how to handle rapid diagnostic tests for COVID-19 in a fully vaccinated population [Review of studies of mainly moderate quality]	No	Rapid review	Other	Mitton C, Smith N, Lakzadeh P, Kim D. Rapid Diagnostic Testing for COVID-19 in a fully vaccinated population. Report prepared for the SPOR Evidence Alliance and COVID-END, June 2021.
		Methods used in the test	2020-04-01	8/11	No	[All tests] RT-PCR using sputum samples is the most sensitive method to diagnose COVID-19, followed by the use of CT scan, with a general observation that respiratory samples are more sensitive regardless of the analysis technique used	No	Full review	Test accuracy	Böger B, Fachi MM, Vilhena RO, Cobre AF, Tonin FS, Pontarolo R. Systematic review with meta-analysis of the accuracy of diagnostic tests for COVID-19 [published online ahead of print, 2020 Jul 10]. Am J Infect Control. 2020;S0196-6553(20)30693-3. doi:10.1016/j.ajic.2020.07.011
			2020-09-30	10/11	No	[CT scan] While important heterogeneity among studies was found, available evidence suggests that chest CT scan is sensitive but has moderate specificity, which was found to be higher low prevalence settings [Review mainly based on low quality studies]	Yes (row content last checked on 2021-10-18)	Full review	Test accuracy	Islam N, Ebrahimzadeh S, Salameh J-P, Kazi S, Fabiano N, Treanor L et al. Thoracic imaging tests for the diagnosis of COVID‐19. Cochrane Database of Systematic Reviews. 2021;9:Art. No.: CD013639. DOI: 10.1002/14651858.CD013639.pub4.
			2020-09-06	9/11	No	[CT scan] The diagnostic accuracy of a chest CT scan might not be sufficient to diagnose COVID-19, particularly for its low specificity [Review of studies of mainly moderate quality with important heterogeneity among their findings]	No	Full review	Test accuracy	Pang C, Hou Q, Yang Z, Ren L. Chest computed tomography as a primary tool in COVID-19 detection: An update meta-analysis. Clinical Translational Imaging. 2021.
			2021-01-01	6/11	No	[CT scan] CT scan assisted by artificial intelligence algorithms has shown to have a 90% pooled sensitivity and 95% specificity [Review of studies of unknown quality and heterogeneity among their findings]	No	Full review	Test accuracy	Moezzi M, Shirbandi K, Shahvandi HK, Arjmand B, Rahim F. The diagnostic accuracy of Artificial Intelligence-Assisted CT imaging in COVID-19 disease: A systematic review and meta-analysis. Inform Med Unlocked. 2021;24:100591.
			2021-02-26	7/11	No	[CT scan] Using CT-based radiomics to distinguish COVID-19 from other viral pneumonia had a pooled sensitivity of 88.5% and a pool specificity of 81.1% [Review of studies of low to moderate quality and important heterogeneity among some of their outcomes]	No	Full review	Test accuracy	Kao YS, Lin KT. A meta-analysis of computerized tomography-based radiomics for the diagnosis of COVID-19 and viral pneumonia. Diagnostics. 2021;11(6):991.
			2020-04-25	6/11	No	[Lung ultrasound] Lung ultrasound can be a contributor to diagnosing COVID-19, but not to confidently rule out the disease	No	Full review	Test accuracy	Mohamed MFH, Al-Shokri S, Yousaf Z, et al. Frequency of Abnormalities Detected by Point-of-Care Lung Ultrasound in Symptomatic COVID-19 Patients: Systematic Review and Meta-Analysis. Am J Trop Med Hyg. 2020.
			2020-09-30	10/11	No	[Lung ultrasound] While important heterogeneity among studies was found, available evidence suggests that lung ultrasound is moderately sensitive but has very low specificity [Review mainly based on low quality studies]	Yes (row content last checked on 2021-10-18)	Full review	Test accuracy	Islam N, Ebrahimzadeh S, Salameh J-P, Kazi S, Fabiano N, Treanor L et al. Thoracic imaging tests for the diagnosis of COVID‐19. Cochrane Database of Systematic Reviews. 2021;9:Art. No.: CD013639. DOI: 10.1002/14651858.CD013639.pub4.
			2020-09-30	6/10	No	[PET/CT] PET/CT with 2-[(18)F]FDG as a radiopharmaceutical appears to have limited utility to diagnose COVID-19 compared with high resolution CT; it may have a role in detecting incidental lesions suspicious of COVID when used for other indications.	No	Full review	Other	Annunziata S, Bolton RCD, Kamani CH, Prior JO, Albano D, Bertagna F, et al. Role of 2-[(18)F]FDG as a radiopharmaceutical for PET/CT in patients with COVID-19: A systematic review. Pharmaceuticals. 2020;13(11):E377.
			2020-07-17	8/10	Yes	[RT-PCR] The false-negative (patients incorrectly diagnosed as not having COVID-19) rate of patients undergoing RT-PCR tests is uncertain, hence repeat testing is necessary where the diagnosis is in doubt	Yes (row content last checked on 2021-10-18)	Full review	Test accuracy	Arevalo-Rodrigues I, Bultrago-Garcia D, Simancas-Racines D, Zambrano-Achig P, del Campo R, Ciapponi A, Sued O, Martinez-Garcia L, Rutjes A, Low N, Bossuyt PM, Perez-Molina JA, Zamora J. False negative results of initial RT-PCR assays for COVID-19: A systematic review. 2020.
			2020-09-30	10/11	No	[X-ray] While important heterogeneity among studies was found, available evidence suggests that lung ultrasound is moderately sensitive but has low specificity [Review mainly based on low quality studies]	Yes (row content last checked on 2021-10-18)	Full review	Test accuracy	Islam N, Ebrahimzadeh S, Salameh J-P, Kazi S, Fabiano N, Treanor L et al. Thoracic imaging tests for the diagnosis of COVID‐19. Cochrane Database of Systematic Reviews. 2021;9:Art. No.: CD013639. DOI: 10.1002/14651858.CD013639.pub4.
		Methods (type of specimen)	2020-05-02	8/11	No	Although the sensitivity of serologic-based to detect either present or past infection are around 80%, its performance is still highly dependant on the prevalence of COVID-19	No	Full review	Test accuracy	de Moura DTH, McCarty TR, Ribeiro IB, Funari MP, de Oliveira PVAG, de Miranda Neto AA, et al. Diagnostic characteristics of serological-based COVID-19 testing: A systematic review and meta-analysis. Clinics. 2020;75:e2212.
			2020-09-10	7/9	No	Evidence suggests a relationship between the time from collection of a specimen, copy threshold, and symptom severity when doing SARS-CoV-2 culture, and also suggests that a positive PCR test in isolation may not imply infectivity [Review mainly based on low quality studies]	Yes (row content last checked on 2021-10-18)	Full review	Other	Jefferson T, Spencer E, Brassey J, Heneghan C. Viral cultures for COVID-19 infectivity assessment - A systematic review. Clinical Infectious Diseases. 2020;ciaa1764.
			2020-05-07	8/10	No	While important variation in the diagnostic accuracy of serological tests for COVID-19 was found, IgA and/or IgG based chemoluminiscense immunoassays was the most accurated followed by ELISA [Review of studies mainly of low quality]	No	Full review	Test accuracy	Mekonnen D, Mengist HM, Derbie A, Nibret E, Munshea A, He H, et al. Diagnostic accuracy of serological tests and kinetics of severe acute respiratory syndrome coronavirus 2 antibody: A systematic review and meta-analysis. Reviews in Medical Virology. 2020;e2181.
			2020-08-31	8/11	No	Pooled analyses suggest the sensitivity of PCR tests is imperfect when based on respiratory samples (although RT-PCR was found to be more sensitive than other PCRs) although specificity has been found to be consistently high [Review of studies including COVID-19 and other coronaviruses]	No	Full review	Test accuracy	Hellou MM, Górska A, Mazzaferri F, Cremonini E, Gentilotti E, De Nardo P, et al. Nucleic-acid-amplification tests from respiratory samples for the diagnosis of coronavirus infections: Systematic review and meta-analysis. Clinical Microbiology and Infection. 2020.
			2020-06-01	9/11	No	Among serological tests detecting antibodies to diagnose COVID-19, detection of IgM+ or IgG+ had the highest sensitivity, while all the panels studied had favourable specificity, and diagnostic accuracy improved in serological tests conducted 2 weeks after symptom onset [Review of studies of variable quality]	No	Full review	Test accuracy	Chen M, Qin R, Mei J, Yang Z, Wen W, Li J. Clinical applications of detecting IgG, IgM, or IgA antibody for the diagnosis of COVID-19: A meta-analysis and systematic review. International Journal of Infectious Diseases. 2021.
			2020-08-01	8/11	No	Using saliva and deep throat sputum specimens seems to have a reliable test accuracy to diagnose SARS-CoV-2 infection [Review of studies of moderate quality and moderate heterogeneity among their findings]	No	Full review	Test accuracy	Khiabani K, Amirzade-Iranaq MH. Are saliva and deep throat sputum as reliable as common respiratory specimens for SARS-CoV-2 detection? A systematic review and meta-analysis. American Journal of Infection Control. 2021:(21).
			N/A (Protocol)	n/a	No	[Protocol - results not yet available] A review evaluating SARS-CoV-2 viral shedding in fluids involved in the sex act is currently being conducted	Yes (row content last checked on 2021-08-30)	Protocol	Other	Gonsalves L, Kara E, Broutet N, de Leon RGP, Cala DC, Peña CGM, et al. Viral shedding of SARS-CoV-2 in bodily fluids involved in the sex act: A living systematic review. PROSPERO. 2020; CRD42020204741.
			N/A (Protocol)	n/a	No	[Protocol - results not yet available] A review evaluating the diagnostic accuracy of respiratory tract specimens for the detection of SARS-CoV-2 is currently being conducted	Yes (row content last checked on 2021-08-30)	Protocol	Test accuracy	Moore A, Nakahata M, Kalinich C, Nyhan K, Bromberg D, Shi X, et al. The sensitivity of respiratory tract specimens for the detection of SARS-CoV-2: A living systematic review and meta-analysis. PROSPERO. 2020;CRD42020196585.
		Methods (site from where specimen is taken)	2020-04-01	8/11	No	RT-PCR using sputum samples is the most sensitive method to diagnose COVID-19, followed by the use of CT scan, with a general observation that respiratory samples are more sensitive regardless of the analysis technique used	No	Full review	Test accuracy	Böger B, Fachi MM, Vilhena RO, Cobre AF, Tonin FS, Pontarolo R. Systematic review with meta-analysis of the accuracy of diagnostic tests for COVID-19 [published online ahead of print, 2020 Jul 10]. Am J Infect Control. 2020;S0196-6553(20)30693-3. doi:10.1016/j.ajic.2020.07.011
			2020-04-19	7/10	No	In children with SARS-CoV-2 infection, viral shedding samples have been found to be present for longer in feces compared to the respiratory tract; this may be of relevance in relation to different possible routes of transmission.	No	Full review	Other	Santos VS, Gurgel RQ, Cuevas LE, Martins-Filho PR. Prolonged fecal shedding of SARS-CoV-2 in pediatric patients. A quantitative evidence synthesis [published online ahead of print, 2020 May 22]. J Pediatr Gastroenterol Nutr. 2020;10.1097/MPG.0000000000002798. doi:10.1097/MPG.0000000000002798
			2020-04-30	6/10	No	The likelihood of a positive SARS-CoV-2 test using a respiratory sample decreases with time from symptoms onset, with sputum specimens showing the highest positivity rates, and oropharyngeal swabs the lowest	No	Full review	Other	Mohammadi A, Esmaeilzadeh E, Li Y, Bosch RJ, Li J. SARS-CoV-2 detection in different respiratory sites: A systematic review and meta-analysis. Medrxiv. 2020.
			2020-06-01	7/11	No	Low prevalence of ocular manifestations of COVID-19 was found and a very low PCR positivity rate on ocular samples [Review of observational studies]	No	Full review	Test accuracy	La Distia Nora R, Putera I, Khalisha DF, Septiana I, Ridwan AS, Sitompul R. Are eyes the windows to COVID-19? Systematic review and meta-analysis. BMJ Open Ophthalmology. 2020;5(1).
			2020-08-10	7/11	No	Fecal viral nucleic acid was present in a high number of children with COVID-19, although the characteristics of patients having stool samples positive for viral nucleic acid with symptom resolution remains uncertain [Review of studies of unknown quality]	No	Full review	Other	Wang JG, Cui HR, Tang HB, Deng XL Gastrointestinal symptoms and fecal nucleic acid testing of children with 2019 coronavirus disease: A systematic review and meta-analysis. Scientific Reports. 2020;10(1):17846.
			2020-11-01	7/11	No	No important differences were found on the sensitivity of testing for SARS-CoV-2 infection with saliva versus nasopharyngeal swabs, although the results substantially change depending on the method of saliva collection [Review of observational studies of variable quality]	No	Full review	Test accuracy	Bastos ML, Perlman-Arrow S, Menzies D, Campbell JR. The sensitivity and costs of testing for SARS-CoV-2 infection with saliva versus nasopharyngeal swabs: A systematic review and meta-analysis. Annals of Internal Medicine. 2021.
			2020-12-30	8/11	No	In diagnosing SARS-CoV-2 infection, saliva has been shown to be the best candidate as an alternative specimen to oropharyngeal swabs, whereas urine, feces and tears were found to perform worse [Review of studies of variable quality and high heterogeneity among their results]	No	Full review	Other	Moreira VM, Mascarenhas P, Machado V, Botelho J, Mendes JJ, Taveira N, et al. Diagnosis of SARS-Cov-2 infection by RT-PCR using specimens other than naso- and oropharyngeal swabs: A systematic review and meta-analysis. Diagnostics (Basel). 2021;11(2):363.
			2020-11-12	8/11	No	Using saliva to detect SARS-CoV-2 by RT-PCR methods has shown to have high sensitivity (from 82% to 92%) and variable specificity (from 75% to 98%) compared to oropharyngeal and nasopharyngeal swabs [Review of observational studies of variable quality and high heterogeneity among their findings]	No	Full review	Test accuracy	Atieh MA, Guirguis M, Alsabeeha NHM, Cannon RD. The diagnostic accuracy of saliva testing for SARS-CoV-2: A systematic review and meta-analysis. Oral Dis. 2021.
			2020-04-29	8/11	No	Serological tests evaluating IgG and IgM to diagnose COVID-19 were found to have a high specificity, whereas its sensitivity depends highly on the methods used (lateral flow immunoassay, chemiluminescence enzyme immunoassay, fluorescence enzyme-linked immunoassay and ELISA systems)[Review of studies of mainly low quality and important heterogeneity among their findings]	No	Full review	Test accuracy	Vengesai A, Midzi H, Kasambala M, Mutandadzi H, Mduluza-Jokonya TL, Rusakaniko S et al. A systematic and meta-analysis review on the diagnostic accuracy of antibodies in the serological diagnosis of COVID-19. Syst Rev. 2021;10(1):155.
		Speeding results	2020-05-25	9/11	No	Important heterogeneity in the diagnostic accuracy of point-of-care antigen and molecular tests to diagnose SARS-CoV-2 infection was found [Review mainly based on low or unclear quality studies]	Yes (row content last checked on 2021-10-18)	Full review	Test accuracy	Dinnes J, Deeks JJ, Adriano A, Berhane S, Davenport C, Dittrich S, et al. Rapid, point‐of‐care antigen and molecular‐based tests for diagnosis of SARS‐CoV‐2 infection. Cochrane Database of Systematic Reviews. 2020;(8):Art. No.: CD013705. DOI: 10.1002/14651858.CD013705.
			2020-09-28	9/11	No	The majority of isothermal nucleic acid point-of-care tests have reported at least 90% sensitivity and specificity, but the diagnostic accuracy increased in samples with medium to high viral load, without needing a RNA sample purification step [Review of studies mainly of low quality conducted during COVID-19 and other coronaviruses outbreaks]	No	Full review	Test accuracy	Subsoontorn P, Lohitnavy M, Kongkaew C. The diagnostic accuracy of isothermal nucleic acid point-of-care tests for human coronaviruses: A systematic review and meta-analysis. Scientific Reports. 2020;10(1):22349.
			2020-08-10	8/11	No	Point-of-care testing using molecular assays offer 94% sensitivity and very high specificity in the detection of SARS-CoV-2 [Review of studies of variable quality and high heterogeneity]	No	Full review	Test accuracy	Yoon SH, Yang S, Cho H, Eun S, Koo CM, Kim MK. Point-of-care testing for the detection of SARS-CoV-2: A systematic review and meta-analysis. European Review for Medical and Pharmacological Sciences. 2021;25(1):503-517.
			2020-11-20	5/11	No	Only two rapid-antigen tests (Roche/SDB and Abbott) were found to provide enough real-world performance data to confirm that they are able to detect current SARS-CoV-2 infection [Review of studies of unknown quality]	No	Full review	Test accuracy	Hayer J, Kasapic D, Zemmrich C. Real-world clinical performance of commercial SARS-CoV-2 rapid antigen tests in suspected COVID-19: A systematic meta-analysis of available data as of November 20, 2020. International Journal of Infectious Diseases. 2021;108:592-602.
			2021-06-15	7/9	No	Limited evidence is available on how to handle rapid diagnostic tests for COVID-19 in a fully vaccinated population [Review of studies of mainly moderate quality]	No	Rapid review	Other	Mitton C, Smith N, Lakzadeh P, Kim D. Rapid Diagnostic Testing for COVID-19 in a fully vaccinated population. Report prepared for the SPOR Evidence Alliance and COVID-END, June 2021.
	Isolation of suspected or confirmed cases		N/A (protocol)	n/a	Yes	[Protocol - results not yet available] A systematic review exploring behaviour-management strategies to aid self-isolation for unwilling and unable individuals during the COVID-19 pandemic is currently being conducted	No	Protocol	Other	Bahji A, Crockford D. Behaviour management strategies to aid self-isolation for unwilling and unable individuals during the COVID-19 pandemic: a systematic review. PROSPERO. 2020;CRD42020208155.
			2020-12-09	7/11	No	Estimates show that 25% (CI 95% 16 to 38) of COVID-19 cases do not develop symptoms throughout the course of infection [Review of studies of unknown quality and substantial heterogeneity among their findings]	No	Full review	Other	Alene M, Yismaw L, Assemie MA, Ketema DB, Mengist B, Kassie B, et al. Magnitude of asymptomatic COVID-19 cases throughout the course of infection: A systematic review and meta-analysis. PLoS One. 2021;16(3):e0249090.
			2020-12-01	6/11	No	The mean incubation period for COVID-19 has been estimated at 6.2 days, but the data are varied, and much longer incubation periods in a small percentage of people cannot be ruled out' [Review of studies of low quality with significant heterogeneity among their findings]	No	Full review	Other	Dhouib W, Maatoug J, Ayouni I, Zammit N, Ghammem R, Fredj SB, et al. The incubation period during the pandemic of COVID-19: A systematic review and meta-analysis. Systematic Reviews. 2021;10:101.
	Contact tracing		2020-05-05	10/10	Yes	Digital contact tracing technologies used alongside manual methods and other public-health measures such as isolation may successfully identify secondary cases and could save time, but there is limited evidence about their effectiveness, acceptability and implementation in real-world outbreak settings	No	Rapid review	Benefits and harms	Anglemyer A, Moore THM, Parker L, Chambers T, Grady A, Chiu K, et al. Digital contact tracing technologies in epidemics: A rapid review. Cochrane Database of Systematic Reviews 2020, Issue 8. Art. No.: CD013699. DOI: 10.1002/14651858.CD013699
			2020-04-30	6/9	No	A systematic review found no empirical studies comparing automated with manual contact tracing systems for COVID-19 or other infectious diseases, but modelling studies suggest that the effectiveness of contact tracing depends on disease context, timeliness of case identification and notification, tracers' expertise, case and contact definitions, and behavioral factors	No	Full review	Benefits and harms	Braithwaite I, Callender T, Bullock M, Aldridge RW. Automated and partly automated contact tracing: A systematic review to inform the control of COVID-19. The Lancet Digital Health. 2020;2(11):e607-e621.
			2020-07-15	9/9	No	Feelings of collective responsibility motivate people to engage in contact-tracing systems, but this motivating factor must outweigh privacy concerns, mistrust of government or public-health officials and be reinforced by clear and consistent information about the personal and collective benefits of these systems [Review of studies conducted during COVID-19, Ebola and other outbreaks]	No	Rapid review	Other	Megnin-Viggars O, Carter P, Melendez-Torres GJ, Weston D, Rubin GJ. Facilitators and barriers to engagement with contact tracing during infectious disease outbreaks: A rapid review of the evidence. PLoS One. 2020;15(10):e0241473.
			2020-10-28	9/10	No	Existing non-empirical evidence shows that contact tracing apps can be effective when added to manual contact tracing for reducing transmission of SARS-CoV-2 [Review of observational and non-empirical studies mainly of low quality]	No	Rapid review	Benefits and harms	Jenniskens K, Bootsma MCJ, Damen JAAG, Oerbekke MS, Vernooij RWM, Spijker R, et al. Effectiveness of contact tracing apps for SARS-CoV-2: A rapid systematic review. BMJ Open. 2021;11(7):e050519.
	Susceptibility tracking
		Antibody testing	2020-05-01	7/9	No	Existing studies suggest urgency to examine seroprevalence may have compromised methodological rigour, restricting the conclusions that can be drawn about the link between prevalence and immunity to COVID-19	Yes (row content last checked on 2021-10-18)	Rapid review	Other	Bobrovitz N, Arora R, Yan T, Rahim H, Duarte N, Bouher E, et al. Lessons from a Rapid Systematic Review of Early SARS-CoV-2 Serosurveys. MedRxiv 2020.
			2020-04-27	11/11	No	Antibody testing appears to be a potentially appropriate approach for detecting previous SARS-CoV-2 infection when taken 15 days after symptom onset, with uncertainty remaining about their application beyond 35 days after symptom onset	No	Full review	Test accuracy	Deeks JJ, Dinnes J, Takwoingi Y, Davenport C, Spijker R, Taylor-Phillips S, et al. Antibody tests for identification of current and past infection with SARS-CoV-2. Cochrane Database Syst Rev. 2020 Jun 25;
			2020-04-04	9/11	Yes	FDA authorized serology tests to detect SARS-CoV-2 antibodies probably have a high sensitivity and specificity, but their diagnostic accuracy is optimal 15 or more days post symptom onset	No	Full review	Test accuracy	Rajesh P & Anand G. Diagnostic accuracy of FDA authorized serology tests to detect SARS-CoV-2 antibodies: A systematic review and meta-analysis. medRxiv. 2020.
			2020-09-18	7/9	No	The potential for COVID-19 re-infection and for new transmission after recovery is currently uncertain	Yes (row content last checked on 2021-10-18)	Rapid review	Other	National Collaborating Centre for Methods and Tools. Rapid Review Update 3: What is known on the potential for COVID-19 re-infection, including new transmission after recovery? Hamilton, ON: National Collaborating Centre for Methods and Tools; 2020.
			2020-05-04	4/10	No	Extensive variability in the sensitivity estimates across tests used to detect antibodies to SARS-CoV-2 was found [Review mainly based on low quality studies]	Yes (row content last checked on 2021-10-18)	Rapid review	Test accuracy	Jarrom D, Elston L, Washington J, Prettyjohns M, Cann K, Myles S, et al. The effectiveness of tests to detect the presence of SARS-CoV-2 virus, and antibodies to SARS-CoV-2, to inform COVID-19 diagnosis: A rapid systematic review. BMJ Evidence-Based Medicine. 2021.
			2020-12-22	8/11	No	A highly variable seroprevalence of human infection with SARS-CoV-2 was found among different WHO regions, with South-East Asia having the highest seroprevalence, and individuals aged 20-64 years more likely to be seropositive than young and older people [Review of studies of mainly low quality]	No	Full review	Other	Chen X, Chen Z, Azman AS, Deng X, Sun R, Zhao Z, Zheng N, Chen X, Lu W, Zhuang T, Yang J, Viboud C, Ajelli M, Leung DT, Yu H. Serological evidence of human infection with SARS-CoV-2: a systematic review and meta-analysis. The Lancet. Global Health. 2021 Mar 8:S2214-109X(21)00026-7.
		Antibody test usage	2020-04-03	4/9	No	No evidence was found to inform clinical or public-health implications of serological antibody testing as priority indications for COVID-19 [Review of observational studies mainly of low quality]	No	Rapid review	Other	Alberta Health Services, COVID-19 Scientific Advisory Group. Priority indications for serologic testing for COVID-19 rapid review. Alberta: Alberta Health Services, COVID-19 Scientific Advisory Group; 2020
Broader public-health measures
	Risk stratification
		Stratifying the population by risk of infection	N/A (Protocol)	n/a	No	[Protocol - results not yet available] A systematic review to explore the association between demographic factors and a COVID-19 diagnosis in patients is currently being conducted	Yes (row content last checked on 2021-08-30)	Protocol	Other	Atherley A, Derckx R, Dijkstra J, Franssen G, Hendriks S, Jolani S, et al. Demographic Factors and COVID-19: a Rapid and Living Systematic Review and Meta-Analysis. PROSPERO 2020; CRD42020180085.
			N/A (Protocol)	n/a	No	[Protocol - results not yet available] A systematic review to explore the association between lifestyle factors and a COVID-19 diagnosis is currently being conducted	Yes (row content last checked on 2021-08-30)	Protocol	Other	Wesselius A, der Ven E, Bongaerts B, Dijksma I, Ament S, Falahi F, et al. Lifestyle Factors and COVID-19: a Rapid and Living Systematic Review and Meta-Analysis. PROSPERO 2020; CRD42020181902.
			2020-07-08	7/11	No	Healthcare workers, particularly nurses, report a high prevalence of SARS-CoV-2 infection, with a significant proportion of asymptomatic or pre-symptomatic carriers	Yes (row content last checked on 2021-10-18)	Full review	Other	Gómez-Ochoa SA, Franco OH, Rojas LZ, Raguindin PF, Roa-Diaz ZM, Wyssmann BM, et al. COVID-19 in healthcare workers: A living systematic review and meta-analysis of prevalence, risk factors, clinical characteristics, and outcomes. American Journal of Epidemiology. 2020.
			2021-07-18	6/11	No	The relationship between smoking status and infection, hospitalization and mortality is uncertain; current smokers may be at reduced risk of infection compared with non-smokers (although they appear to be more likely to be tested), but former smokers may have an increased risk of hospitalisation and greater disease severity [Review of observational studies]	Yes (row content last checked on 2021-10-18)	Rapid review	Other	Simons D, Shahab L, Brown J, Perski O. The association of smoking status with SARS-CoV-2 infection, hospitalisation and mortality from COVID-19: A living rapid evidence review with Bayesian meta-analyses (version 12). Addiction. 2021.
			2020-07-25	7/11	No	Secondary attack rates averaged at about 18% with substantial heterogeneity, with higher rates in households and other residential settings and when infections are symptomatic [Review of observational studies]	No	Full review	Other	Koh WC, Naing L, Chaw L, Rosledzana MA, Alikhan MF, Jamaludin SA, et al. What do we know about SARS-CoV-2 transmission? A systematic review and meta-analysis of the secondary attack rate and associated risk factors. medRxiv. 2020;15(10):e0240205.
			2020-06-10	5/9	No	Some evidence shows that children with COVID-19 appear more likely to be asymptomatic, and adult to child transmission seems to be less likely than child to child or child to adult transmissions [Review of studies of unknown quality]	Yes (row content last checked on 2021-10-18)	Rapid review	Other	COVID-19 Scientific Advisory Group. What role might children play in community SARS-CoV-2 transmission? What measures might mitigate potential additional risk of transmission of COVID-19 related to school and daycare reopening? Calgary, AB: Alberta Health Services; 2020.
			2020-12-15	6/10	No	Most adults infected with COVID-19 develop antibodies that peaked between 20-25 days after the onset of symptoms before declining, and are detectable for at least 120 days; neutralizing antibody activity may also last for several months, and antibody prevalence may not vary by age or sex	Yes (row content last checked on 2021-10-18)	Rapid review	Other	Arkhipova-Jenkins I, Helfand M, Armstrong C, Gean E, Anderson J, Paynter RA, et al. Antibody response after SARS-CoV-2 infection and implications for immunity. Annals of Internal Medicine. 2021.
			2021-10-07	8/11	No	Estimates of the global seroprevalence of SARS-CoV-2 antibodies remain relatively low with important variations among geographical regions and specific populations [Review of studies of variable quality] See the interactive map of the global seroprevalence here (https://serotracker.com/en/Explore)	Yes (row content last checked on 2021-10-18)	Full review	Other	Bobrovitz N, Arora RK, Cao C, Boucher E, Liu M, Rahim H, et al. Global seroprevalence of SARS-CoV-2 antibodies: A systematic review and meta-analysis. medRxiv. 2021.
			2021-04-05	8/11	No	Patients who have reduced levels of IgG antibodies, and possibly those with a milder form of infection, may be more likely to have repeated infection [Review of studies of unknown quality and important heterogeneity among their findings]	No	Full review	Other	Dembrovszky F, Váncsa S, Farkas N, Erőss B, Szakó L, Teutsch B et al. Immunoglobulin response and prognostic factors in repeated SARS-CoV-2 positive patients: A systematic review and meta-analysis. Viruses. 2021;13(5):809.
			2021-05-12	7/10	No	The risk of re-infection has found to be relatively low for at least ten months post-infection, whereas immune memory responding to SARS-CoV-2 infection has been found up to nine months post infection; important uncertainty exists about the role that natural infection and vaccination might play in the context of variants of concern [Review of studies of low to moderate quality]	Yes (row content last checked on 2021-10-18)	Full review	Other	Health Information and Quality Authority, Ireland. Duration of immunity (protection from reinfection) following SARS-CoV-2 infection. Cork, Ireland: Health Information and Quality Authority, Ireland; 2021.
			2020-06-10	8/9	No	No robust evidence has been found allowing assessments of an association between vitamin D supplementation or serum vitamin D levels with susceptibility to COVID-19 infection [Review of observational studies of mainly low quality]	No	Full review	Other	Grove A, Osokogu O, Al-Khudairy L, Mehrabian A, Zanganeh M, Brown A, et al. Association between vitamin D supplementation or serum vitamin D level and susceptibility to SARS-CoV-2 infection or COVID-19 including clinical course, morbidity and mortality outcomes? A systematic review. BMJ Open. 2021;11(5):e043737.
			2021-03-21	8/11	No	Evidence shows that COVID-19 infects all blood types, but the infection rates are different, although the reuslts are highly heterogeneous (i.e., A > 0 > B > AB) [Review of studies of variable quality ]	No	Full review	Other	Kabrah SM, Kabrah AM, Flemban AF, Abuzerr S. Systematic review and meta-analysis of the susceptibility of ABO blood group to COVID-19 infection. Transfusion and Apheresis Science. 2021;103169.
			2021-02-19	8/10	No	The risk of reinfection in individuals with prior evidence of infection was low for up to 10 months, although further evidence is needed on how these findings might change with variants of concern [Review of studies of moderate quality]	No	Full review	Other	Murchu EO, Byrne P, Carty PG, De Gascun C, Keogan M, O'Neill M, et al. Quantifying the risk of SARS-CoV-2 reinfection over time. Reviews in Medical Virology. 2021;e2260.
			2021-05-06	8/11	No	Patients with mild to moderate COVID-19 and who have suppressed immune systems more frequently show recurrent PCR positivity [Review of studies of moderate quality]	No	Full review	Other	Ren X, Wang X, Ge Z, Cui S, Chen Z. Clinical features and corresponding immune function status of recurrent viral polymerase chain reaction positivity in patients with COVID-19 : A meta- analysis and systematic review. International Journal of Immunopathology and Pharmacology. 2021;35.
			2020-10-23	8/11	No	Micronutrients deficiency (particularly vitamin D) was found to be associated with an increased incidence of COVID-19 [Review of mainly observational studies with important heterogeneity among their findings]	No	Full review	Other	Wang MX, Gwee SXW, Pang J. Micronutrients deficiency, supplementation and novel coronavirus infections - A systematic review and meta-analysis. Nutrients. 2021;13(5):1589.
			2021-01-16	8/11	No	Evidence studying patients with hemoglobinopathies suggests that, compared to the general population, patients with sickle-cell disease have higher COVID-19 infection rates [Review of studies of important heterogeneity among some of their findings]	No	Full review	Other	Haghpanah S, Hosseini-Bensenjan M, Sayadi M, Karimi M. Incidence rate of COVID-19 infection in hemoglobinopathies: A systematic review and meta-analysis. Hemoglobin. 2021:1-9.
			2021-04-15	9/11	No	Evidence shows that individuals who are black and Hispanic are more affected by COVID-19 when measured by cases, hospitalizations and deaths [Review of studies on unknown quality with important heterogeneity among their findings]	No	Full review	Other	Mude W, Oguoma VM, Nyanhanda T, Mwanri L, Njue C. Racial disparities in COVID-19 pandemic cases, hospitalisations, and deaths: A systematic review and meta-analysis. Journal of Global Health. 2021;11:05015.
			2021-03-10	4/10	No	Evidence shows that close contacts and family clusters are the main route of COVID-19 transmission, although children are less likely to be infected than adults within a family cluster [Review of studies of unknown quality]	No	Full review	Other	Song WL, Zou N, Guan WH, Pan JL, Xu W. Clinical characteristics of COVID-19 in family clusters: A systematic review. World Journal of Pediatrics. 2021.
	Outbreak management
		Locations (essential services or other)	2020-06-26	7/10	No	Outbreak investigations show that long-term care facilities are more vulnerable to the COVID-19 pandemic, in terms of disease spread and mortality rate	Yes (row content last checked on 2021-10-18)	Full review	Other	Salcher-Konrad M, Jhass A, Naci H, Tan M, El-Tawil Y, Comas-Herrera A. COVID-19 Related Mortality and Spread of Disease in Long-Term Care: First Findings from a Living Systematic Review of Emerging Evidence. MedRxiv 2020.
			2021-02-01	8/10	No	Implementation of a comprehensive COVID-19 plan, with strategies to prevent introduction of COVID-19 into long-term care facilities, identify and isolate cases, decrease likelihood of transmission and provide high-quality medical care to residents, may be effective to reduce both viral transmission and mortality within-long term care homes	No	Rapid review	Other	National Collaborating Centre for Methods and Tools. Rapid review update 2: What risk factors are associated with COVID-19 outbreaks and mortality in long-term care facilities and what strategies mitigate risk? National Collaborating Centre for Methods and Tools. 2021;
		Rapid-response mechanisms
	Pandemic tracking
		Levels of re-emergence that trigger action	2020-05-20	8/10	No	While no evidence has been found on the effectiveness of wastewater-based surveillance to monitor the COVID-19 pandemic, reports and retrospective analyses show that COVID-19 has been detected in untreated wastewater	No	Rapid review	Other	National Collaborating Centre for Methods and Tools. Rapid review: What is known about using wastewater surveillance to monitor the COVID-19 pandemic in the community? Hamilton: National Collaborating Centre for Methods and Tools; 2020
			2020-08-31	7/11	No	Although important geographical variations were found among estimations of case fatality ratios, estimates of the reproduction number was 2.69 [Review of studies of unknown quality with a substantial heterogeneity among their findings]	No	Full review	Other	Ahammed T, Anjum A, Rahman MM, Haider N, Kock R, Uddin MJ. Estimation of novel coronavirus (COVID-19) reproduction number and case fatality rate: A systematic review and meta-analysis. Health Sci Rep. 2021;4(2):e274.

* This topic has been the focus of extensive academic debate (see here), and the evidence is frequently being updated

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.