Tuberculosis Vaccine Improves Immune Response to Coronavirus

By Reuters Staff

March 18, 2022

(Reuters) - New research sheds light on how a tuberculosis vaccine might help protect against COVID-19.

Early in the pandemic, studies began to suggest that people who received the Bacillus Calmette Guérin (BCG) vaccine as children had lower rates of SARS-CoV-2 infection. Research in hamsters now shows that animals vaccinated with BCG had less pneumonia due to COVID-19 and lower levels of the coronavirus in their lungs.

Doctors at Johns Hopkins University in Baltimore found important differences in lung cells between animals infected with SARS-CoV-2 who did or did not get the BCG vaccine, they reported on bioRxiv ahead of peer review. Upon infection with the coronavirus, for the BCG-treated animals, antibodies came to lung cells much faster, lung repair mechanisms got underway much more quickly, and tissue-damaging inflammation was blunted, said coauthor Dr. William Bishai.

Earlier this month, researchers in India reported on the effects of BCG in recipients of the COVID-19 vaccine from AstraZeneca in a small study. The 21 subjects who had received the TB vaccine showed significantly "more robust" antibody- and T-cell attacks against the coronavirus than the 13 people who had not, they reported on Research Square ahead of peer review.

Combining BCG vaccines with COVID-19 vaccines "may offer synergistic protection," the Johns Hopkins team said. Clinical trials testing BCG vaccines for protection against COVID-19 are underway.

SOURCE: bioRxiv, online March 15, 2022 and Research Square, online March 2, 2022.