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

Nat Rev Immunol. 2020 Jun;20(6):335-337. doi: 10.1038/s41577-020-0337-y.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • BCG Vaccine / immunology
  • BCG Vaccine / therapeutic use*
  • Betacoronavirus
  • COVID-19
  • Coronavirus Infections / immunology
  • Coronavirus Infections / prevention & control*
  • Humans
  • Immunity, Innate
  • Immunogenicity, Vaccine
  • Pandemics / prevention & control*
  • Pneumonia, Viral / immunology
  • Pneumonia, Viral / prevention & control*
  • SARS-CoV-2


  • BCG Vaccine