Bacillus Calmette-Guérin (BCG) vaccine, which primarily provides protection against tuberculosis (TB), is also beneficial against coronavirus disease (Covid-19) among elderly people, scientists at the Indian Council of Medical Research (ICMR) have concluded.
The results have been published in a pre-print study.
ICMR scientists have been investigating the impact of BCG vaccination on the frequencies of immunity cells–T cell, B cell, monocyte (white blood cells), and dendritic (antigen-presenting) cell subsets — and total antibody levels in a group of healthy elderly people, who are aged between 60 and 80 years, a month after their vaccination as part of a clinical study to examine its effect on Covid-19 patients.
Elderly people, who are aged above 60 years, and those with comorbidities such as diabetes, hypertension, cardiac and kidney diseases etc; are considered as high-risk groups. They tend to develop severe forms of illness, and also have a high mortality rate among Covid-19 patients.
“BCG vaccination was associated with enhanced innate and adaptive memory cell subsets, as well as total antibody levels in elderly individuals, suggesting its potential utility in SARS-CoV2 infection, which causes Covid-19, by enhancing heterologous immunity,” scientists concluded in the research.
The BCG vaccine is administered to newborn babies as a part of the Centre’s Universal Immunisation Programme (UIP), which was launched over 50 years ago.
“In an ongoing study, scientists at ICMR have found that the BCG vaccine induces increased memory cell responses and total antibody production in elderly,” said an ICMR statement.
From July through September, 86 individuals were enrolled in the study, including 54 and 32 in the vaccinated and unvaccinated arms, respectively. All the vaccinated individuals were followed up a month after their vaccination.
The median age was 65 (range: 60-78) years in the BCG vaccinated group and 63 years (range: 60-80) in the unvaccinated group.
Several clinical trials are in progress to examine the effect of BCG.
ICMR scientists zeroed in on an investigation in elderly population because most BCG studies are evaluating its role in protecting healthcare workers and other individuals from the viral infection.
Negligible studies are examining the protective effect of BCG vaccination against Covid-19 in the elderly population group.
Previous studies in elderly individuals have shown that BCG vaccination protected against respiratory infections in Indonesia, Japan, and Europe.
“These data fit very well with the recent finding that BCG vaccination in elderly patients was associated with increased time to first infection and protection against viral respiratory pathogens,” the paper stated.
