COVID-19, caused by a novel coronavirus, SARS-CoV-2, contributes significantly to the morbidity and mortality in humans worldwide. In the absence of specific vaccines or therapeutics available, COVID-19 cases are managed empirically with the passive immunity approach and repurposing of drugs used for other conditions. Recently, a concept that bacilli Calmette–Guerin (BCG) vaccination could confer protection against COVID-19 has emerged. The foundation for this widespread attention came from several recent articles, including the one by Miller et al. submitted to MedRxiv, a pre-print server. The authors of this article suggest that a correlation exists between countries with a prolonged national BCG vaccination program and the morbidity/mortality due to COVID-19. Further, clinical BCG vaccination trials are currently ongoing in the Netherlands, Australia, the UK, and Germany with the hope of reducing mortality due to COVID-19. Although BCG vaccination helps protect children against tuberculosis, experimental studies have shown that BCG can also elicit a non-specific immune response against viral and non-mycobacterial infections. Here, we summarize the pros and cons of BCG vaccination and critically analyze the evidence provided for the protective effect of BCG against COVID-19 and highlight the confounding factors in these studies.
【저자키워드】 COVID-19, SARS-CoV-2, pandemic, Tuberculosis, trained immunity, BCG, 【초록키워드】 Vaccine, immune response, vaccination, Trial, children, Human, passive immunity, drug, Novel coronavirus, infections, Germany, morbidity and mortality, correlation, non-specific, protective effect, Evidence, Netherlands, BCG vaccination, COVID-19 case, help, medRxiv, reducing mortality, National, widespread, approach, country, articles, highlight, Miller, PROTECT, shown, caused, significantly, provided, contribute, absence, elicit, submitted, conditions, confounding factor, 【제목키워드】 Still,