Evidence about public-health measures

Evidence syntheses on this webpage are organized by:

  1. vaccine safety and efficacy and real-world effectiveness
  2. 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)
  3. infection control (screening, quarantining, testing, isolation, contact tracing, and susceptibility tracking)
  4. 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
Date of last search Quality (AMSTAR) rating Evidence-certainty (e.g., GRADE) assessment available             Key findings
Living evidence synthesisType of synthesis             Type of question
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)2022-01-057/9NoThis living review presents a detailed analysis on the efficacy and effectiveness of available COVID-19 vaccines against variants of concernYes (row content last checked on 2022-01-10)Rapid reviewBenefits and harms
Iorio A, Little J, Linkins L, Abdelkader W, Bennett D, Lavis JN. COVID-19 living evidence profile #6 (version 6.22): 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 January 2022.

   2021-12-178/9NoThis website provides a summary of the efficacy of COVID-19 vaccines based on clinical trials dataYes (row content last checked on 2022-01-10)Full review Benefits and harms COVID NMA. Overall effectiveness and safety of all vaccines vs placebo. 2021.
   2021-07-127/11YesThis website provides a summary of the efficacy of COVID-19 vaccines based on clinical trials dataYes (row content last checked on 2022-01-10)Full reviewBenefits and harmsPan American Health Organization. Pfizer-BioNTech COVID-19 vaccine - Efficacy and effectiveness of the vaccine. Pan American Health Organization.; 2021.
   2021-02-088/11NoA 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 efficacyNoFull reviewBenefits and harmsCalzetta 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 three doses if two doses were recommended before the emergence of variants        
  Effectiveness when administered at large scaleN/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 conductedNo 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.  
   2021-05-118/9NoEvidence shows that high transmission of variants of concern in the same household is concerning, and vaccine roll-out combined with non-pharmaceutical interventions (including lockdowns, quarantines and physical distancing) are expected to limit the number of deaths and preserve ICU capacity [Review of studies of low to moderate quality]Yes (row content last checked on 2022-01-10)Rapid reviewOtherCurran 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.
   2021-05-046/9NoA 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 2022-01-10)Rapid reviewOtherEgunsola 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/aNo[Protocol - results not yet available] A review exploring the transmission of COVID-19 after vaccination is currently being conductedYes (row content last checked on 2021-08-30)ProtocolOtherHooper 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 segmentN/A (Protocol)n/aYes[Protocol - results not yet available] A systematic review evaluating the differential benefits and harms of available vaccines among different ethnic groups is currently being conductedNoProtocolBenefits and harmsWei 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/aYes[Protocol - results not yet available] A review evaluating the safety of COVID-19 candidate vaccines on pregnant women is currently being conductedNoProtocolBenefits and harmsCiapponi 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/aNo[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 conductedYes (row content last checked on 2021-08-30)ProtocolBenefits and harmsFisher 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/aYes[Protocol - results not yet available] A review evaluating the efficacy and immunogenicity of COVID-19 vaccines in pregnant and breastfeeding women is currently being conductedNoProtocolBenefits and harmsGoncalves 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/aYes[Protocol - results not yet available] A review evaluating the side effects of COVID-19 vaccines in pregnant and breastfeeding women is currently being conductedNoProtocolBenefits and harmsGoncalves 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.
   2021-03-104/9NoLimited evidence suggests that immunocompromised patients could produce an attenuated immune response after being vaccinated against COVID-19 [Review of observational studies of unclear quality]NoFull reviewBenefits and harmsCOVID-19 Critical Intelligence Unit. Immunocompromised patients and COVID-19 vaccines. NSW Government. 2021.
   2021-10-069/10YesVaccination 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; vaccination in individuals with previous COVID-19 infection may slightly reduce the risk of infection compared to those without previous infectionYes (row content last checked on 2022-01-10)Rapid reviewBenefits and harmsNational Collaborating Centre for Methods and Tools. Rapid Review Update 1: What is the ongoing 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/aNo[Protocol - results not yet available] A review evaluating the efficacy and safety of COVID-19 vaccines on pregnant and breastfeeding women is currently being conductedYes (row content last checked on 2021-09-07)ProtocolBenefits and harmsLow JM & Low YW. Efficacy and safety of COVID-19 vaccine: A systematic review and meta-analysis in pregnant and breastfeeding individuals. PROSPERO. 2021;CRD42021266203.
   2021-01-045/11NoEvidence shows that vaccination against COVID-19 appears to be safe in patients undergoing anti-CD20 therapy, but vaccine response may be lower than in the general population [Review of studies of variable quality, conducted before the COVID-19 pandemic]NoFull reviewBenefits and harmsVijenthira A, Gong I, Betschel SD, Cheung M, Hicks LK. Vaccine response following anti-CD20 therapy: A systematic review and meta-analysis of 905 patients. Blood Advances. 2021;5(12):2624-2643.
  Complementary vaccines2021-03-108/11NoA 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]NoFull reviewOtherWang 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
4/9No 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 isolationNo 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 settingsNo 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* 2020-05-0311/11Yes 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; low certainty evidence suggests N95 respirators and eye protection can lead to a reduction in viral infections, whereas physical distancing of more than one metre probably results in a large reduction of viral infections
Yes (row content last checked on 2022-01-10)Full reviewBenefits 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
6/10No 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, whereas PPE use by healthcare workers has been found to be one of the strongest factors associated with reduced risk of coronavirus infectionYes (row content last checked on 2022-01-10)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 conductedNo 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 
   2020-11-189/11NoEvidence 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]NoFull reviewBenefits and harmsOllila 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.
   2021-03-166/10NoPublic-health measures and non-pharmacological interventions (including compulsory mask wearing, community wide masking policies, travel and border restrictions, and quarantining travellers) may be effective for mitigating the spread of COVID-19 [Review of studies of low to moderate quality]NoFull reviewOtherAyouni 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 equipment2020-05-03 11/11 YesLarge 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; low certainty evidence suggests N95 respirators and eye protection can lead to a reduction in viral infections, whereas physical distancing of more than one metre probably results in a large reduction of viral infectionsYes (row content last checked on 2022-01-10)Full reviewBenefits and harmsChu 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
  2021-07-026/10NoWhereas 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, whereas PPE use by healthcare workers has been found to be one of the strongest factors associated with reduced risk of coronavirus infectionYes (row content last checked on 2022-01-10)Full reviewBenefits 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 NoThe safety of different decontamination methods for reusing surgical masks in clinical settings is uncertain
Yes (row content last checked on 2022-01-10)Full reviewBenefits and harmsZorko 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 Whereas the effectiveness of different types of PPE, PPE modifications, and procedures to prevent exposure among healthcare workers is uncertain, easy to doff gowns, and gown-glove improvements may be better than standard gowns and gloves, and providing donning and doffing instructions as well as using extra sanititation for doffing may reduce the risk of contamination Yes (row content last checked on 2022-01-10)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 Whereas the effectiveness of different types of PPE, PPE modifications, and procedures to prevent exposure among healthcare workers is uncertain, easy to doff gowns, and gown-glove improvements may be better than standard gowns and gloves, and providing donning and doffing instructions as well as using extra sanititation for doffing may reduce the risk of contamination Yes (row content last checked on 2022-01-10)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 
   2021-10-24
6/10 No Using PPE was found to be the strongest factor associated with reducing risk of coronavirus infection among healthcare workers, while wearing two filtering facepiece masks was associated with a reduced risk of COVID-19 infection, when compared to a single surgical mask [Review of observational studies]Yes (row content last checked on 2022-01-10)Rapid review OtherChou R, Dana T, Buckley DI, Selph S, Fu R, Totten AM. Update alert 10: Epidemiology of and risk factors for coronavirus infection in health care workers. Annals of Internal Medicine. 2021;
   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 2022-01-10)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 2022-01-10)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. 
   2020-08-045/9NoMedical staff could be at risk of developing pressure injuries while wearing protective equipment for long periods of time to prevent COVID-19 infection, whereas patients in prone position to treat COVID-19 could be at risk of developing pressure injuries when connected to a mechanical ventilator for long periods [Review of observational studies]NoFull reviewOtherYu 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.
   2021-05-118/9NoEvidence shows that high transmission of variants of concern in the same household is concerning, and vaccine roll-out combined with non-pharmaceutical interventions (including lockdowns, quarantines and physical distancing) are expected to limit the number of deaths and preserve ICU capacity [Review of studies of low to moderate quality]Yes (row content last checked on 2022-01-10)Rapid reviewOtherCurran 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 fragmentsYes (row content last checked on 2022-01-10)Rapid reviewOther 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 2022-01-10)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.  
   2020-05-218/10NoA 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]NoRapid reviewOtherGoodwin 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 2020-05-0311/11YesLarge 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; low certainty evidence suggests N95 respirators and eye protection can lead to a reduction in viral infections, whereas physical distancing of more than one metre probably results in a large reduction of viral infections
Yes (row content last checked on 2022-01-10)Full reviewBenefits and harmsChu 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 deperssion 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 Whereas economic evaluations show that screening programs may be a cost-effective strategy to control COVID-19, when these economic evaluations use a long time horizon, social distancing measures were found to be more cost-effective than quarantine, non-intervention, or herd immunityNo Full review Costs and cost-effectivenessRezapour 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/aNo[Protocol - results not yet available] A review evaluating the cost-effectiveness of public health interventions, including quarantines and social distancing, is currently being conductedNoProtocolCosts and cost-effectivenessRayanakorn A, Chaiprom P, Lee SWH. Cost-effectiveness of public health interventions on COVID-19 control: A systematic review and meta-analysis. PROSPERO. 2021; CRD42021243848 
   2021-05-118/9NoEvidence shows that high transmission of variants of concern in the same household is concerning, and vaccine roll-out combined with non-pharmaceutical interventions (including lockdowns, quarantines and physical distancing) are expected to limit the number of deaths and preserve ICU capacity [Review of studies of low to moderate quality]Yes (row content last checked on 2022-01-10)Rapid reviewOtherCurran 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 conductedYes (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/aNo[Protocol - results not yet available] A review evaluating SARS-CoV-2 viral shedding in fluids involved in the sex act is currently being conductedYes (row content last checked on 2021-08-30)ProtocolOtherGonsalves 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
6/11NoPeople 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 effectiveYes (row content last checked on 2022-01-10)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 conductedNo 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. 
   2021-03-126/9NoEvidence 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]NoFull reviewOtherRegmi 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. 
   2020-10-016/11NoHigh 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]NoFull reviewViews and experiencesNwagbara 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. 
   2021-05-268/10NoNoRapid reviewBenefits and harmsGold 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.
   2021-03-055/9NoMask use in community settings appears to protect against transmission and other adverse health outcomes related to COVID-19 infection [Review of ecological studies of variable quality]NoFull reviewOtherFord N, Holmer HK, Chou R, Villeneuve PJ, Baller A, Van Kerkhove M, et al. Mask use in community settings in the context of COVID-19: A systematic review of ecological data. EClinicalMedicine. 2021;38:101024.
  Health worker and essential worker-focused behaviour change supports for the above2020-03-20
9/10 Yes Whereas the effectiveness of different types of PPE, PPE modifications, and procedures to prevent exposure among healthcare workers is uncertain, easy to doff gowns, and gown-glove improvements may be better than standard gowns and gloves, and providing donning and doffing instructions as well as using extra sanititation for doffing may reduce the risk of contamination Yes (row content last checked on 2022-01-10)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. 
   2020-11-037/9YesThe risks of dispersion or aerosol generation and infection transmission with nasopharyngeal and oropharyngeal swabs are uncertainNoFull reviewOtherAgarwal 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.
   2020-12-015/9NoThe 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 2022-01-10)Rapid reviewOtherGoldstein 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.
  Other2020-07-21
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 patientsNoFull reviewBenefits 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.
   2021-02-017/10NoAlthough 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]NoFull reviewBenefits and harmsMohebbi 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/aYes[Protocol - results not yet available] A review evaluating the effects of mouthwashes on the viral load of SARS-CoV-2 in saliva is currently being conductedYes (row content last checked on 2021-12-06)ProtocolBenefits and harmsCosta C, Nogueira M, Araújo J. Do mouthwashes reduce the SARS-CoV-2 viral load in saliva in vivo? A living systematic review. PROSPERO. 2021;CRD42021250335.
   N/A (Protocol)n/aYes[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 conductedYes (row content last checked on 2021-08-30)ProtocolBenefits and harmsMorales 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. 
   2020-08-015/9NoWhereas 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]NoFull reviewBenefits and harmsHammond 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. 
   2021-01-147/10NoEvidence 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]NoFull reviewBenefits and harmsLiu 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.
   2021-01-048/10NoEcological studies showed an association between increasing temperature and humidity and reducing COVID-19 mortality, whereas the association with wind speed was ambiguous [Review of studies of mainly low quality with inconsistency among their findings]NoFull reviewOtherRomero Starke K, Mauer R, Karskens E, Pretzsch A, Reissig D, Nienhaus A, et al. The effect of ambient environmental conditions on COVID-19 mortality: A systematic review. International Journal of Environmental Research and Public Health. 2021;18(12):6665.
 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 2022-01-10)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. 
   2020-04-17
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, while 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.  
   2020-06-214/9NoThe limited evidence available assessing the role of children in the transmission of SARS-CoV-2 suggests that children may be unlikely to play an important role in overall transmission [Review of studies of unknown quality]Yes (row content last checked on 2022-01-10)Rapid reviewOtherLi 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. 
   2021-06-146/10NoCOVID-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]NoRapid reviewOtherEgunsola 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.
   2021-03-317/9NoPresymptomatic and asymptomatic infected individuals are probably capable of transmitting the SARS-CoV-2 virus , although there are important limitations with assessing symptom status and infectivity at a single point of time, [Review of studies of unclear quality]Yes (row content last checked on 2022-01-10)Full reviewOtherJefferson T, Spencer EA, Brassey J, Onakpoya IJ, Rosca EC, Plüddemann A, et al. Transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) from pre and asymptomatic infected individuals. A systematic review. Clinical Microbiology and Infection. 2021. 
  Methods2020-05-29
9/11 NoNon-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 certaintly 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, while modelling studies suggest that screening at travel hubs may slightly slow the importation of infected cases 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 Whereas economic evaluations show that screening programs may be a cost-effective strategy to control COVID-19, when these economic evaluations use a long time horizon, social distancing measures were found to be more cost-effective than quarantine, non-intervention, or herd immunityNo 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, whereas the average incubation period has been estimated to be five days, and the duration of illness to dyspnea, onset of symptoms to hospital admission, hospital admission to ICU admission, and first symptom to death ocurred in an average of 13, six, five and 17 days, respectively; 62% of COVID-19 patients are required to remain in hospital after initial admission [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.  
   2021-01-2510/11YesTaste disorders among COVID-19 patients occurs in 38% of the cases, whereas it may be more frequent in men than women; the prevalence of xerstomia in COVID-19 patients is 43% [Review of studies with substantial heterogeneity among their findings]Yes (row content last checked on 2022-01-10)Full reviewOtherAmorim Dos Santos J, Normando AGC, Carvalho da Silva RL, Acevedo AC, De Luca Canto G, Sugaya N, et al. Oral manifestations in patients with COVID-19: A 6-month update. Journal of Dental Research. 2021;100(12):1321-1329.
   N/A (Protocol)n/aNo[Protocol - results not yet available] A review evaluating the characteristics and clinical outcomes of COVID-19 patients infected with variants of concern is currently being conductedYes (row content last checked on 2022-01-10)ProtocolOtherChoi S, Pokharel A, Ong KIC, Jimba M. Characteristics and clinical outcomes of patients infected with SARS-CoV-2 variant of concern: A rapid and living systematic review and meta-analysis. PROSPERO. 2021;CRD42021254745.
  Locations (and frequency if applicable) 2020-11-139/10Yes Whereas the majority of the available evidence is uncertain and coming from the pre-COVID era, studies suggest that restricting cross-border travel may reduce the number of imported and exported cases of COVID-19, and reduce the acceleration of epidemic progressionYes (row content last checked on 2022-01-10)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. 
   2021-05-118/9NoEvidence shows that high transmission of variants of concern in the same household is concerning, and vaccine roll-out combined with non-pharmaceutical interventions (including lockdowns, quarantines and physical distancing) are expected to limit the number of deaths and preserve ICU capacity [Review of studies of low to moderate quality]Yes (row content last checked on 2022-01-10)Rapid reviewOtherCurran 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 2020-04-019/11NoOne 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
NoFull reviewBenefits and harmsJefferson 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.
   2020-06-237/10 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; the effectiveness of quarantining individuals travelling from a country with a declared outbreak is uncertainYes (row content last checked on 2022-01-10)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. 
   2020-11-139/10Yes Whereas the majority of the available evidence is uncertain and coming from the pre-COVID era, studies suggest that restricting cross-border travel may reduce the number of imported and exported cases of COVID-19, and reduce the acceleration of epidemic progressionYes (row content last checked on 2022-01-10)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 Fever, cough, myalgia and dyspnea were found to be the most common symptoms among COVID-19 patients, whereas the average incubation period has been estimated to be five days, and the duration of illness to dyspnea, onset of symptoms to hospital admission, hospital admission to ICU admission, and first symptom to death ocurred in an average of 13, six, five and 17 days, respectively; 62% of COVID-19 patients are required to remain in hospital after initial admission [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/aNo[Protocol - results not yet available] A review evaluating the cost-effectiveness of public health interventions, including quarantines and social distancing, is currently being conductedNoProtocolCosts and cost-effectivenessRayanakorn A, Chaiprom P, Lee SWH. Cost-effectiveness of public health interventions on COVID-19 control: A systematic review and meta-analysis. PROSPERO. 2021; CRD42021243848 
   2021-03-126/9NoEvidence 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]NoFull reviewOtherRegmi 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. 
   2021-05-118/9NoEvidence shows that high transmission of variants of concern in the same household is concerning, and vaccine roll-out combined with non-pharmaceutical interventions (including lockdowns, quarantines and physical distancing) are expected to limit the number of deaths and preserve ICU capacity [Review of studies of low to moderate quality]Yes (row content last checked on 2022-01-10)Rapid reviewOtherCurran 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.
   2021-01-265/9NoLimited evidence is available on the measures to support people in isolation or quarantine during the COVID-19 pandemic [Review of studies of low quality]NoRapid reviewOtherCardwell K, O’Neill SM, Tyner B, Broderick N, O’Brien K, Smith SM, et al. A rapid review of measures to support people in isolation or quarantine during the Covid-19 pandemic and the effectiveness of such measures. Reviews in Medical Virology. 2021;e2244.
 Testing        
  Optimizing testing across different types of individuals, settings and timing options2020-05-01
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. 
   2020-05-016/10NoDrive-through testing was one of the most common approaches implemented for population testing for SARS-CoV-2 [Review of observational studies of unkown quality]NoFull reviewOtherFoster 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. 
   2020-09-296/9NoThe 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]NoRapid reviewOtherPark 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
   2020-08-116/11NoEvidence 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]NoFull reviewOtherSpielberger 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. 
   2021-06-157/9NoLimited 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]NoRapid reviewOtherMitton 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 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 usedNo 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 While important heterogeneity among studies was found, available evidence suggests that chest CT scan is sensitive but has moderate specificity, lung ultrasound is moderately sensitive but has very low specificity and X-rays are moderately sensitive with low specificity [Review mainly based on low quality studies]Yes (row content last checked on 2022-01-10)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.
   2020-09-069/11No[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]NoFull reviewTest accuracyPang 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.
   2021-01-016/11No[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]NoFull reviewTest accuracyMoezzi 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. 
   2021-02-267/11No[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]NoFull reviewTest accuracyKao 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
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.NoFull 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 2022-01-10)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.
  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
7/9NoEvidence 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 2022-01-10)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.  
   2020-08-018/11NoUsing 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]NoFull reviewTest accuracyKhiabani 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/aNo[Protocol - results not yet available] A review evaluating SARS-CoV-2 viral shedding in fluids involved in the sex act is currently being conductedYes (row content last checked on 2021-08-30)ProtocolOtherGonsalves 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/aNo[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 conductedYes (row content last checked on 2021-08-30)ProtocolTest accuracyMoore 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 usedNoFull 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. NoFull 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.  
   2020-12-308/11NoIn 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]NoFull reviewOtherMoreira 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. 
   2020-11-128/11NoUsing 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]NoFull reviewTest accuracyAtieh 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.
   2020-04-298/11NoSerological 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]NoFull reviewTest accuracyVengesai 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 2020-11-16
9/11 No Whereas important heterogeneity in the diagnostic accuracy of point-of-care antigen and molecular tests to diagnose SARS-CoV-2 infection was found, studies shows that in average antigen tests show a 72% of sensitivity and 58% of specificity, whereas molecular tests had a 95.1% of sensitivity and 99% of sensitivity (but the results of the latter were mainly coming from out of point-of-care settings) [Review mainly based on low or unclear quality studies]Yes (row content last checked on 2022-01-10)Full review Test accuracy Dinnes J, Deeks JJ, Berhane S, Taylor M, Adriano A, Davenport C, et al. Rapid, point‐of‐care antigen and molecular‐based tests for diagnosis of SARS‐CoV‐2 infection. Cochrane Database of Systematic Reviews. 2021;3: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.  
   2021-06-157/9NoLimited 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]NoRapid reviewOtherMitton 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.
   2021-04-3010/11No

The diagnostic accuracy of antigen rapid diagnostic tests for COVID-19 has been estimated at 71.2% sensitivity and 98.9% specificity, and is particularly high when performed during the first week of illness, although a large number of studies did not perform the tests following manufacturers recommendations [Review of studies of variable quality and important heterogeneity among some of their findings]

See most updated version in this link: https://www.klinikum.uni-heidelberg.de/diagnostics-global-health

Yes (row content last checked on 2022-01-10)Full reviewTest accuracyBrümmer LE, Katzenschlager S, Gaeddert M, Erdmann C, Schmitz S, Bota M, et al. The accuracy of novel antigen rapid diagnostics for SARS-CoV-2: A living systematic review and meta-analysis. PLOS Medicine. 2021;18(8):e1003735.
 Isolation of suspected or confirmed casesN/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 conductedNo 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. 
  2020-12-097/11NoEstimates 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]NoFull reviewOtherAlene 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.
  2020-12-016/11NoThe 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]NoFull reviewOtherDhouib 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 tracing2020-05-05
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 NoRapid reviewBenefits 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 
  2020-07-15
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. 
  2020-10-289/10NoExisting 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]NoRapid reviewBenefits and harmsJenniskens 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.
  2021-01-315/9NoContact-tracing apps have been widely used in East Asia during the COVID-19 pandemic, with government mistrust and a lack of  mandatory use policies identified as the main barriers to implementing them [Review of studies of unclear quality]NoFull reviewOtherAkinbi A, Forshaw M, Blinkhorn V. Contact tracing apps for the COVID-19 pandemic: A systematic literature review of challenges and future directions for neo-liberal societies. Health Information Science. 2021;9(1):18.
 Susceptibility tracking        
  Antibody testing 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 2022-01-10)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 onsetNo 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 2022-01-10)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
4/10NoExtensive 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 2022-01-10)Rapid reviewTest 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. 
   2020-12-228/11NoA 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]NoFull reviewOtherChen 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 conductedYes (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 (including dietary, smoking and physical activity habits) and a COVID-19 diagnosis is currently being conductedYes (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 2022-01-10)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 2022-01-10)Rapid reviewOther 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; whereas the effects of closing schools are uncertain, children appear to be less likely to be infected by SARS-CoV-2 at schools compared to home settings [Review of studies of unknown quality] Yes (row content last checked on 2022-01-10)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. 
   2020-12-156/10NoMost 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 sexYes (row content last checked on 2022-01-10)Rapid reviewOtherArkhipova-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.
   2022-01-048/11No

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 2022-01-10)Full reviewOtherBobrovitz 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.
   2021-04-058/11NoPatients 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]NoFull reviewOtherDembrovszky 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. 
   2021-05-127/10NoThe 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 2022-01-10)Full reviewOtherHealth 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.
   2021-03-218/11NoEvidence 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 ]NoFull reviewOtherKabrah 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.
   2020-04-216/10NoIndividuals with blood group A were more susceptible to COVID-19 infection, while individuals with blood group O were less susceptible; no associated was found in other blood groups [Review of moderate quality studies with important heterogeneity among some of their findings]Yes (row content last checked on 2022-01-10)Rapid reviewOtherPourali F, Afshari M, Alizadeh-Navaei R, Javidnia J, Moosazadeh M, Hessami A. Relationship between blood group and risk of infection and death in COVID-19: A live meta-analysis. New Microbes and New Infections. 2020;
   2021-02-198/10NoThe 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]NoFull reviewOtherMurchu 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.
   2021-05-068/11NoPatients with mild to moderate COVID-19 and who have suppressed immune systems more frequently show recurrent PCR positivity [Review of studies of moderate quality]NoFull reviewOtherRen 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.
   2020-10-238/11NoMicronutrients 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]NoFull reviewOtherWang MX, Gwee SXW, Pang J. Micronutrients deficiency, supplementation and novel coronavirus infections - A systematic review and meta-analysis. Nutrients. 2021;13(5):1589.
   2021-01-168/11NoEvidence 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]NoFull reviewOtherHaghpanah 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. 
   2021-04-159/11NoEvidence 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]NoFull reviewOtherMude 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.  
   2021-03-104/10NoEvidence 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]NoFull reviewOtherSong 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.
   2021-02-019/11NoNo association has been found between mood disorders and the risk of getting a COVID-19 infection [Review of studies of mainly moderate quality with important heterogeneity among their findings]NoFull reviewOtherCeban F, Nogo D, Carvalho IP, Lee Y, Nasri F, Xiong J, et al. Association between mood disorders and risk of covid-19 infection, hospitalization, and death: A systematic review and meta-analysis. JAMA Psychiatry. 2021.
   2021-05-107/11NoLow serum vitamin D levels may be associated with an increased risk of COVID-19 incidence [Review of studies of mainly moderate quality with important heterogeneity among their findings]NoFull reviewBenefits and harmsSzarpak L, Rafique Z, Gasecka A, Chirico F, Gawel W, Hernik J, et al. A systematic review and meta-analysis of effect of vitamin D levels on the incidence of COVID-19. Cardiology Journal. 2021.
   N/A (Protocol)n/aYes[Protocol - results not yet available] A review evaluating risk factors for getting COVID-19 among healthcare workers is currently being conductedYes (row content last checked on 2022-01-10)ProtocolOtherDzinamarira T, Mhango M, Dzobo M, Ngara B, Chitungo I, Makanda P, et al. Risk factors for COVID-19 among healthcare workers. A protocol for a systematic review and meta-analysis. PLoS ONE. 2021;16(5): e0250958.
 Outbreak management        
  Locations (essential services or other) 2020-06-267/10NoOutbreak 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 2022-01-10)Full reviewOtherSalcher-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.
   2021-02-018/10 NoImplementation 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 homesYes (row content last checked on 2022-01-10)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 action2020-05-208/10NoWhile 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 wastewaterNoRapid reviewOtherNational 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
   2020-08-317/11NoAlthough 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]NoFull reviewOtherAhammed 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