Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2020 Jun;20(6):335-337.
doi: 10.1038/s41577-020-0337-y.

BCG-induced trained immunity: can it offer protection against COVID-19?

Luke A J O'Neill  1 , Mihai G Netea  2   3   4
Affiliations
Review

BCG-induced trained immunity: can it offer protection against COVID-19?

Luke A J O'Neill et al. Nat Rev Immunol. 2020 Jun.

Abstract

Bacillus Calmette–Guérin (BCG) vaccination has been reported to decrease susceptibility to respiratory tract infections, an effect proposed to be mediated by the general long-term boosting of innate immune mechanisms, also termed trained immunity. Here, we discuss the non-specific beneficial effects of BCG against viral infections and whether this vaccine may afford protection to COVID-19.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing interests.

Figures

Fig. 1
Fig. 1. Trained immunity antiviral host defence.
a | Bacillus Calmette–Guérin (BCG) vaccination has been shown to protect against multiple viral pathogens, including respiratory syncytial virus (RSV), influenza A virus and herpes simplex virus type 2 (HSV2). Will it protect against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)? b | Trained immunity leading to enhanced innate immune responses to different pathogens after a vaccination is mediated by metabolic and epigenetic rewiring in innate immune cells, which leads to increased gene transcription and improved host defence. c | Trained immunity as a tool for enhancing population immunity during a pandemic ahead of the availability of a specific vaccine. TNF, tumour necrosis factor.
See this image and copyright information in PMC

References

    1. Huang C, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet. 2020;395:497–506. doi: 10.1016/S0140-6736(20)30183-5. - DOI - PMC - PubMed
    1. Shann F. The non-specific effects of vaccines. Arch. Dis. Child. 2010;95:662–667. doi: 10.1136/adc.2009.157537. - DOI - PubMed
    1. Aaby P, et al. Randomized trial of BCG vaccination at birth to low-birth-weight children: beneficial nonspecific effects in the neonatal period? J. Infect. Dis. 2011;204:245–252. doi: 10.1093/infdis/jir240. - DOI - PubMed
    1. Stensballe LG, et al. Acute lower respiratory tract infections and respiratory syncytial virus in infants in Guinea-Bissau: a beneficial effect of BCG vaccination for girls community based case-control study. Vaccine. 2005;23:1251–1257. doi: 10.1016/j.vaccine.2004.09.006. - DOI - PubMed
    1. Wardhana, et al. The efficacy of Bacillus Calmette-Guerin vaccinations for the prevention of acute upper respiratory tract infection in the elderly. Acta Med. Indones. 2011;43:185–190. - PubMed

Publication types