Should Bacillus Calmette–Guérin (BCG) vaccine be used in the prophylaxis of COVID-19?

  • Daisy O. Sanchez-Mostiero
  • Abigail F. Melicor
Keywords: covid-19


At present, there is insufficient evidence to support the use of BCG vaccine as prophylaxis for COVID-19.

  • Bacillus Calmette Guerin (BCG) vaccine is an attenuated microorganism derived from bovine tubercle bacillus and

is being given to prevent severe tuberculosis.

  • BCG vaccination may enhance production of antibodies and pro-inflammatory cytokines such as interleukin

(IL)-1β and tumor necrosis factor (TNF). BCG may lead to increased CD4 and CD8 T-cell activity on subsequent

viral infection.

  • Ecological studies on the effect of BCG vaccination policy on COVID-19 outcomes have conflicting results and

are prone to bias from confounders.

  • There is insufficient evidence on the efficacy and safety of BCG vaccine for COVID-19 prophylaxis.
  • Thirteen clinical trials are ongoing among high-risk groups (healthcare workers, elderly, police officers) to evaluate

the efficacy and safety of BCG vaccine in preventing COVID-19 and its severe symptoms.

  • WHO does not recommend the use of BCG vaccine as prophylaxis against COVID-19.
  • Adverse events of BCG vaccine range from mild local cutaneous reactions to systemic adverse events such as

abscess, lymphadenopathy and osteomyelitis.