Tuberculosis Vaccine Could Play Role in COVID-19 Prevention

A group of researchers at Cedars-Sinai Medical Center in Los Angeles have found evidence that a tuberculosis vaccine has been associated with a reduced likelihood of contracting coronavirus disease 2019 (COVID-19). The research also found that the vaccine could help in reducing the level of severity of the disease.

The Bacillus Calmette-Guérin (BCG) vaccine was first developed around 1921 to treat bladder cancer and for people who are at a higher risk of contracting tuberculosis. The vaccine is FDA approved and is administered to over 100 million children every year around the globe.

The Study, published in The Journal of Clinical Investigation, tested for evidence of SARS-CoV-2 in more than 6,000 healthcare workers in the Cedars-Sinai Health system and also asked about their medical and vaccination histories. The study found that 30% of those who had received the BCG vaccine at some point in the past were significantly less likely to test positive for antibodies of SARS-CoV-2. They were also less likely to have reported having had an infection of COVID-19 or having COVID-19 related symptoms.

"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," said Moshe Arditi, MD, co-senior author on the study.

The findings of the study do not represent a view that the BCG vaccine will be more effective than a specific COVID-19 vaccination. However, the BCG vaccine could be approved more quickly and be made more readily available, considering its years of being an approved therapy. The vaccine could be a potential bridge offering some benefit until a more effective and safer COVID-19 vaccine is made widely available.

"Given our findings, we believe that large, randomized clinical trials are urgently needed to confirm whether BCG vaccination can induce a protective effect against SARS-CoV2 infection," said Susan Chang, MD, MPH, MMSc, the other co-lead author of the study.

Numerous randomized clinical trials are already in the works studying the potential of the BCG vaccine for COVID-19. Along with Cedars-Sinai, Baylor College of Medicine and Texas A&M University are leading the research. "It would it be wonderful if one of the oldest vaccines that we have could help defeat the world's newest pandemic," Arditi said.