Journal Article

Considering BCG vaccination to reduce the impact of COVID-19

Netea, Mihai G, Ghebreyesus, Tedros A, Curtis, Nigel, Sparrow, Annie

2020

Overview

In addition to its specific effect against tuberculosis, the BCG vaccine has beneficial nonspecific (off-target) effects on the immune system that protect against a wide range of other infections and are used routinely to treat bladder cancer.1,2 This has led to the suggestion that vaccination with BCG might have a role in protecting health-care workers and other vulnerable individuals against severe coronavirus disease 2019 (COVID-19). In Guinea-Bissau, a high-mortality setting, BCG-Danish reduced all-cause neonatal mortality by 38% (95% CI 17–54), mainly because there were fewer deaths from pneumonia and sepsis.3 In South Africa, BCG-Danish reduced respiratory tract infections by 73% (95% CI 39–88) in adolescents.4 Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a single-stranded positive-sense RNA virus, and the BCG vaccine has been shown to reduce the severity of infections by other viruses with that structure in controlled trials. [...]whether BCG will be effective remains unknown: findings from the ecological studies suggesting less COVID-19 in countries with routine BCG immunisation are weak evidence because they are based on population rather than individual data and are prone to confounding.11 Also, it is unlikely that a BCG vaccine given decades ago in childhood will ameliorate COVID-19 now.

• Publisher: Elsevier Ltd,Elsevier Limited
• Subject: Bacillus Calmette-Guerin vaccine / BCG / BCG Vaccine / Betacoronavirus / Bladder / Children / Coronaviridae / Coronavirus Infections / Coronaviruses / Correspondence / COVID-19 / Ecological effects / Ecological studies / Health care / Humans / Immune system / Immunity, Heterologous / Immunization / Infant mortality / Infections / Mortality / Neonates / Pandemics / Pneumonia, Viral / Public health / Randomized Controlled Trials as Topic / Respiratory diseases / Respiratory tract / Respiratory tract diseases / RNA viruses / SARS-CoV-2 / Sepsis / Severe acute respiratory syndrome coronavirus 2 / Tuberculosis / Vaccination / Vaccines / Viral diseases / Viruses