NEW DELHI: In a development that could have significant implications in the coming times, an ICMR study has found that BCG vaccination induces enhanced innate and adaptive immunity in elderly individuals, which may prove beneficial against the Covid-19 virus.
Those above 60, apart from people with underlying health conditions, are particularly susceptible to serious diseases, in case they contract Covid-19.
Bacillus Calmette-Guerin (BCG) is a live–attenuated vaccine strain of Myobacterium 63 bovis that provides protection against mycobacterial infections such as tuberculosis and leprosy, neonatal sepsis and respiratory infections and lowers childhood mortality.
In India, this vaccine is administered to babies at birth as part of the government’s universal immunisation programme.
The researchers associated with the ICMR’s National Institute for Research in Tuberculosis, Chennai, through the clinical study, have now shown that the same vaccine heightened total antibody levels in elderlies and also strengthened various immunity cells.
“Although our study did not examine the functional effects of these changes in the immune system, our data nevertheless reveal an important role for BCG vaccination in boosting immune responses in the elderly population,” wrote the authors in the paper that has just been released on pre-print server and is yet to be peer-reviewed.
Whether this translates to improved protective immunity to non-specific infections like SARS CoV2 remains to be determined, the authors associated with the paper noted.
As part of the study, the researchers from July through September this year vaccinated 54 individuals while 32 people were part of the unvaccinated arm. Subjects in both arms were aged 60-80 years.
After a month, the investigations showed the positive impact of BCG vaccination on various immunity cells, that included B cells and T cells or memory as well as total antibody levels in those who were given the vaccine shots.
Their result demonstrated that BCG vaccination-induced enhanced frequencies of the immunity cell and in addition, it also resulted in elevated levels of all antibody isotypes.
“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 by enhancing heterologous immunity,” wrote the scientists in the paper.
Senior immunologist Dr Seyed Hasnain who has, in two separate analyses so far, showed that countries and regions with BCG vaccinations have witnessed fewer Covid-19 mortalities, called it a “solid” study.
“The researchers, after analysing the effect on BCG vaccine in elderlies have shown that it strengthens both T cells and B cell responses which is very good news and may have repercussions for Covid-19 vaccine manufacturing,” he said. Dr Hasnain added that it would be interesting to follow up on the subjects given the vaccine and assess the course of disease in them, in case some of them contract Covid-19.