Effectiveness of Bacille Calmette-Guerin Vaccination Policies in Reducing Infection and Severity of COVID-19: a Systematic Review Protocol


Introduction: The bacille Calmette-Guerin (BCG) vaccine is used for the prevention of tuberculosis (TB) worldwide. Evidence reports a much lower incidence of COVID-19 in TB-endemic areas implying a possible protective mechanism of BCG in countries with mandated BCG policies. The objective of the study is to synthesize and critically evaluate the effectiveness of national BCG vaccination policies in reducing infection and severity of COVID-19 in their native population.

Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a comprehensive search using pre-identified keywords will be done in PubMed, Cochrane, HERDIN Plus, WPRIM, Web of Science and EBSCO databases. After the initial selection of studies based on eligibility criteria, methodological appraisal will be conducted using the Joanna Briggs Institute appraisal instruments and an adapted quality assessment checklist for ecologic studies. Relevant data will be extracted and synthesized including reporting descriptive and inferential statistics to interpret results.

Results: The study will generate a systematic review synthesizing evidence regarding the effects of BCG in curtailing the spread of the COVID-19 pandemic.

Discussion: The battle against the COVID-19 pandemic is far from over, and as such, further studies must be undertaken to verify the evidence behind initial strategies in battling it. This includes the use of BCG in decreasing COVID-19 incidence and mortality. The results of the review can ultimately guide health authorities and policy makers create evidence-based decisions regarding BCG vaccination policies and clinical trials related to COVID-19 control and prevention.

Systematic Review Registration: PROSPERO, CRD42021244060

  1. Mathew S, Faheem M, Hassain NA, Benslimane FM, Thani AAA, Zaraket H, et al. Platforms Exploited for SARS-CoV-2 Vaccine Development. Vaccines (Basel). 2020;9(1):11. Available from: http://dx.doi.org/10.3390/vaccines9010011
  2. Wouters OJ, Shadlen KC, Salcher-Konrad M, Pollard AJ, Larson HJ, Teerawattananon Y, et al. Challenges in Ensuring Global Access to COVID-19 Vaccines: Production, Affordability, Allocation, and Deployment. Lancet. 2021;397(10278):1023–34. Available from: http://dx.doi.org/10.1016/S0140-6736(21)00306-8
  3. World Health Organization. Coronavirus Disease (COVID-19). World Health Organization; 2021 [cited 2021 June 24]. Available from: https://extranet.who.int/pqweb/vaccines/covid-19-vaccines
  4. Emanuel EJ, Persad G, Kern A, Buchanan A, Fabre C, Halliday D, et al. An Ethical Framework For Global Vaccine Allocation. Science. 2020;369(6509):1309–12. Available from: http://dx.doi.org/10.1126/science.abe2803
  5. Wang W, Wu Q, Yang J, Dong K, Chen X, Bai X, et al. Global, Regional, and National Estimates of Target Population Sizes for Covid-19 Vaccination: descriptive study. BMJ. 2020;371:m4704. Available from: http://dx.doi.org/10.1136/bmj.m4704
  6. Ledford H. Oxford COVID-Vaccine Paper Highlights Lingering Unknowns About Results. Nature. 2020;588(7838):378–9. Available from: http://dx.doi.org/10.1038/d41586-020-03504-w
  7. Corey L. The Coming COVID-19 Vaccine Scarcity. Johns Hopkins Coronavirus Resource Center. [cited 2021 April 6]. Available from: https://coronavirus.jhu.edu/vaccines/blog/the-coming-covid-19-vaccine-scarcity
  8. Mullard A. How COVID Vaccines Are Being Divvied Up Around The World. Nature. 2020; Available from: http://dx.doi.org/10.1038/d41586-020-03370-6
  9. Our World in Data. Coronavirus (COVID-19) Vaccinations [Internet]. England; 2021 [updated 2021 June 23; cited 2021 June 24]. Available from: https://ourworldindata.org/covid-vaccinations?country=OWID_WRL
  10. Mayo Clinic. Herd Immunity and COVID-19 (coronavirus): What You Need to Know. Mayo Foundation for Medical Education and Research [Internet]. 2021 June 09 [ cited 2021 June 25]. Available from: https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/herd-immunity-and-coronavirus/art-20486808
  11. GAVI. Can the BCG Vaccine Protect Against COVID-19? GAVI: The Vaccine Alliance [Internet]. 2020 May 19 [updated 2020 July 20; cited 2021 June 25]. Available from: https://www.gavi.org/vaccineswork/can-bcg-vaccine-protect-against-covid-19?gclid=Cj0KCQjw2tCGBhCLARIsABJGmZ6zpwewHXeYhEL5zqUtSrsT4bG89ptZWTzwr33kwVWO-ETH2BKnz7YaAjg6EALw_wcB
  12. Mohapatra PR, Mishra B, Behera B. BCG Vaccination Induced Protection From COVID-19. Indian J Tuberc. 2021;68(1):119–24. Available from: http://dx.doi.org/10.1016/j.ijtb.2020.08.004
  13. Gonzalez-Perez M, Sanchez-Tarjuelo R, Shor B, Nistal-Villan E, Ochando J. The BCG Vaccine for COVID-19: First Verdict and Future Directions. Front Immunol. 2021;12:632478. Available from: http://dx.doi.org/10.3389/fimmu.2021.632478
  14. Shamseer L, Moher D, Clarke M, Ghersi D, Liberati A, Petticrew M, et al. Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) 2015: Elaboration and Explanation. BMJ. 2015;350(jan02 1):g7647. Available from: http://dx.doi.org/10.1136/bmj.g7647
  15. Phillips B, Cl B, Sackett D, Badenoch D, Straus S, Haynes B, et al. Levels of Evidence (March 2009). Oxford Centre for Evidence-Based Medicine. [cited 2 Jun 2021]. Available from: https://www.cebm.ox.ac.uk/resources/levels-of-evidence/oxford-centre-for-evidence-based-medicine-levels-of-evidence-march-2009
  16. Page MJ, Moher D, Bossuyt P, Boutron I, Hoffmann T, Mulrow CD., et al. PRISMA 2020 Explanation and Elaboration: Updated Guidance and Exemplars for Reporting Systematic Reviews. BITSS. 2020. Available from: http://dx.doi.org/10.31222/osf.io/gwdhk
  17. Betran AP, Torloni MR, Zhang J, Ye J, Mikolajczyk R, Deneux-Tharaux C, et al. What Is the Optimal Rate of Caesarean Section at Population Level? A systematic review of ecologic studies. Reprod Health. 2015;12(1):57. Available from: http://dx.doi.org/10.1186/s12978-015-0043-6
  18. Aromataris E, Munn Z. JBI Manual for Evidence Synthesis. JBI. 2020. Available from https://synthesismanual.jbi.global . https://doi.org/10.46658/JBIMES-20-01

Articles related to the one you are viewing

There are currently no results to show, please try again later

Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, which permits use, share — copy and redistribute the material in any medium or format, adapt — remix, transform, and build upon the material, as long as you give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. You may not use the material for commercial purposes. If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original. You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit https://creativecommons.org/licenses/by-nc-sa/4.0/.