Bacillus Calmette-Guérin (BCG) vaccine is the live attenuated vaccine form of Mycobacterium bovis used to prevent tuberculosis as well as other mycobacterial infections such as leprosy. The vaccine is also used to treat superficial carcinoma of the bladder [1, 2].
Due to its ability to reduce child mortality (which is not necessarily associated with tuberculosis prevention), it is part of the vaccination schedule in many countries.
It is hypothesized that BCG vaccination is linked to a less severe manifestation of SARS-CoV-2 in the countries that have it on their regular vaccination schedules. In a study preprint published on MedRxiv.org, a research group states that BCG vaccination is a potential new tool in the fight against COVID-19 [3].
Murdoch Children’s Research Institute has organized BRACE, a Phase 3, two-group, multicenter, open-label, randomized, controlled trial of up to 4170 health care workers in Australian hospitals to determine if BCG vaccination reduces the incidence and severity of COVID-19 during the 2020 pandemic [4]. Primary results are expected in October 2020, and full study results are expected in March 2022.
References
- Yamazaki-Nakashimada, M. A., Unzueta, A., Berenise Gámez-González, L., González-Saldaña, N., & Sorensen, R. U. (2020). BCG: a vaccine with multiple faces. Human Vaccines & Immunotherapeutics, 1-10.
- Merle, C. S., Cunha, S. S., & Rodrigues, L. C. (2010). BCG vaccination and leprosy protection: review of current evidence and status of BCG in leprosy control. Expert review of vaccines, 9(2), 209-222.
- Correlation between universal BCG vaccination policy and reduced morbidity and mortality for COVID-19: an epidemiological study
- BCG Vaccination to Reduce the Impact of COVID-19 in Australian Healthcare Workers Following Coronavirus Exposure (BRACE) Trial