Japanese Journal of Infectious Diseases
Online ISSN : 1884-2836
Print ISSN : 1344-6304
ISSN-L : 1344-6304
Original Articles
Effect of BCG Vaccination against SARS-CoV-2 Infection
Ya-Ping LiJie-Wen CaiLi-Juan LiaoHan DingXun-Jie CaoGuo-Dong ZhuXu-Guang Guo
Author information

2022 Volume 75 Issue 3 Pages 302-308


Based on previous studies, we found that Bacillus Calmette–Guérin (BCG) vaccination may play a role in preventing SARS-CoV-2 infection. Therefore, we conducted a meta-analysis to investigate this protective effect. We searched the 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 using the Risk of Bias in Non-randomized Studies of Interventions and the Agency for Healthcare Research and Quality data tools. Review Manager (Version 5.3) was used to conduct all the data analyses. A total of eight studies were ultimately included in our meta-analysis. Our primary analysis found a significantly lower SARS-CoV-2 infection rate in the BCG vaccination group compared to the control group, with an odds ratio of 0.61, (95% confidence interval 0.39 to 0.95, P = 0.03; I2 = 31%, and P = 0.21, respectively). Our study indicates 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.

Content from these authors
© 2022 Authors
Previous article Next article