Research Highlight

BCG may protect elderly against COVID-19 

doi:10.1038/nindia.2021.108 Published online 11 August 2021

Bacillus Calmette-Guérin (BCG), a vaccine against tuberculosis, could reduce inflammation in healthy elderly people1.

The vaccine dampens inflammation by lowering the levels of inflammation-related marker proteins. It also checks the secretion of specific proteins discharged during lung inflammation, a research team from Chennai says.

These findings, the researchers say, show that the vaccine could potentially be used to protect elderly people against COVID-19, which primarily affects the lungs.  

Recent studies have indicated that the BCG vaccine enhances antiviral immune responses, making it a likely candidate in the fight against COVID-19. However, it remains unknown how the vaccine generates such immune responses.

To investigate it, scientists from the ICMR-National Institute for Research in Tuberculosis and the ICMR-National Institute of Epidemiology, both in Chennai, India, vaccinated people between 60 and 80 years living in COVD-19 hotspots. They then measured the levels of inflammation-related proteins such as cytokines, acute-phase proteins (APPs) and matrix metalloproteinases (MMPs) in their blood before and one month after vaccination.   

The researchers found that the vaccine reduced the immune responses in all the vaccinated individuals.  BCG-vaccinated individuals exhibited decreased blood levels of cytokines, APPs and MMPs compared with unvaccinated ones.

Specific small inflammation-related proteins, which have roles in COVID-19, were decreased in the vaccinated individuals. The vaccination also decreased the levels of specific inflammation-related growth factors.

Since BCG vaccination does not increase inflammation, it is safe for elderly individuals, the researchers say.


References

1. Kumar, N. P. et al. Effect of BCG vaccination on proinflammatory responses in elderly individuals. Sci. Adv. 7, eabg7181 (2021)Doi:10.1126/sciadv.abg7181