BCG Vaccination Associated With Less Severe COVID-19 Pneumonia

The American Journal of Preventive Medicine published a new study on April 12, 2021, 'Childhood Bacillus Calmette–Guérin (BCG) Vaccination and Its Association With Less Severe COVID-19 Pneumonia.'

These researchers concluded by saying 'BCG vaccination received in childhood is associated with less severe COVID-19 pneumonia (p=0.028) and milder liver function deficiency, in addition to a lower death rate in BCG-vaccinated patients versus non-vaccinated individuals.'

'Overall, the death rate was significantly lower in the BCG-vaccinated group (4.2%, 5/118) than in the unvaccinated group (19.0%, 55/290.'

'Another unexpected finding is less liver dysfunction in COVID-19 patients with BCG immunization history, which is likely associated with metabolic reprogramming that alters certain metabolites that can function as cofactors in some liver enzymes.'

'However, definitive proof of the BCG vaccine's benefit is required to validate this broad approach, which remains lacking.'

To quantify the BCG vaccines potential use, researchers at Texas A&M University, in collaboration with MD Anderson Cancer Center, Baylor College Medicine, and Cedars Sinai Medical Center, are looking for health care workers, first responders, front line workers, seniors, and those with preexisting health conditions to participate in a study evaluating the BCG vaccine as a booster of the immune response, and to study if this vaccine reduces illness severity from coronavirus.

Previously, the Journal of Clinical Investigation published a related study on November 19, 2020. Investigators tested the blood of more than 6,000 healthcare workers in the Cedars-Sinai Health System in California for evidence of antibodies SARS-CoV-2.

The researchers found that workers who had received BCG vaccinations in the past, nearly 30% of those studied, were significantly less likely to test positive for SARS-CoV-2 antibodies in their blood or to report having had infections with coronavirus or coronavirus-associated symptoms over the prior six months than those who had not received BCG.

These effects were not related to whether workers had received meningococcal, pneumococcal, or influenza vaccinations.

According to Moshe Arditi, M.D., director of Pediatric and Infectious Diseases, Immunology Division at Cedars-Sinai and co-senior author of the study, the reasons for the lower SARS-CoV-2 antibody levels in the BCG group were not clear.

"It appears that BCG-vaccinated individuals either may have been less sick and therefore produced fewer anti-SARS-CoV-2 antibodies, or they may have mounted a more efficient cellular immune response against the virus," commented Dr. Arditi, professor of Pediatrics and Biomedical Sciences, in a press statement.

“It would it be wonderful if one of the oldest vaccines that we have could help defeat the world's newest pandemic," Dr. Arditi added.