Study: BCG Vaccine Protects Elderly Against Respiratory Infections

Results of a recent study showed that the Bacille Calmette-Guérin (BCG) vaccine can protect elderly adults against various respiratory infections—but it’s unclear what effect it could have on the coronavirus disease 2019 (COVID-19).¹

BCG is a vaccine for tuberculosis (TB). Although not widely used in the United States, the vaccine is often given to infants and small children in other countries where TB is common.

For the double-blind randomized clinical trial, which was a joint collaboration between Radboud University Medical Center and the National and Kapodistrian University of Athens, investigators examined the effect that the BCG vaccine had on elderly adults after they were discharged from the hospital.

The investigators assigned the 198 study participants to either receive a placebo or BCG vaccine as they were being discharged from the hospital and then followed the participants for 12 months to determine whether there were any new infections, according to the results of the ACTIVATE study published in Cell.¹ 

Evangelos J. Giamarellos-Bourboulis, MD, PhD, co-coordinator of the study at the 4th Department of Internal Medicine at ATTIKON University Hospital, told Drug Topics® that the investigators discovered a “decrease of overall risk of new infection with the BCG vaccination” among those who received the vaccine.

According to the results, 42.3% of the elderly participants developed an infection in the placebo group, whereas only 25% developed an infection in the BCG group, according to a news release announcing the findings. Those in the treatment arm also took longer to develop their first infection—with an average of 16 weeks after vaccination—compared with 11 weeks in the placebo group.²

“In addition to the clear effect of BCG vaccination on infections in general, the most important observation was that BCG could mainly protect against respiratory infections: BCG-vaccinated elderly people had 75% fewer respiratory infections than the elderly who received placebo,” Giamarellos-Bourboulis said in the release.²

He told Drug Topics® that the types of respiratory infections included respiratory viruses and pneumonia.

Investigators reported no differences in adverse effects between the groups and determined the BCG vaccine was safe for elderly patients.¹

It’s also possible the vaccine could help protect the elderly against COVID-19, but that has not been fully studied. The study began before the coronavirus pandemic began and a low prevalence of COVID-19 among those in the study prevented the investigators from being able to draw any conclusions.²

Giamarellos-Bourboulis said the next step in the research will be to “run trials with BCG vaccination to protect the elderly from COVID-19.”

Several studies are already underway to examine whether the BCG vaccine could also have a protective effect against COVID-19.

References:

1. Giamarellos-Bourboulis EJ, Tsilika M, Moorlag S, et al. Activate: Randomized clinical trial of BCG vaccination against infection in the elderly. Cell. 2020. doi: https://doi.org/10.1016/j.cell.2020.08.051​
2. Elderly people protected against respiratory infections by BCG vaccine. News release. Radboud UMC; September 1, 2020. Accessed October 6, 2020. https://www.radboudumc.nl/en/nieuws/2020/elderly-people-protected-against-respiratory-infections-by-bcg-vaccine