Based on previous studies, we found that Bacillus Calmette-Guérin(BCG) vaccination may have a role in preventing SARS-CoV-2 infection. Thus, we conducted this meta-analysis to investigate this protective effect. We searched in Embase, PubMed, Web of Science, Cochrane Library, BioRxiv, and MedRxiv databases for studies that evaluated the relationship between BCG vaccination and SARS-CoV-2 infection or COVID-19 disease. The quality of all included studies was assessed through the Risk of Bias in Non-randomized Studies - of Interventions and the Agency for Healthcare Research and Quality. Review Manager (Version 5.3) was used for conducting all data analyses. A total of 8 studies were ultimately included in our meta-analysis. Our primary analysis found significantly lower SARS-CoV-2 infection rate in the BCG vaccination group compared to the control group, with a odds ratio (OR) of 0.61, (95% confidence interval (CI) 0.39 to 0.95, P = 0.03; I2 = 31%, and P = 0.21 for heterogeneity). Our study indicated that BCG vaccination can protect against SARS-CoV-2 infection. However, there is insufficient evidence that BCG vaccination can reduce the severity of COVID-19.

  • All age groups
  • Efficacy/effectiveness
  • Vaccine/vaccination
  • Tuberculosis
  • COVID-19