Hyderabad: A study conducted by Indian Council of Medical Research (ICMR) researchers on elderly people between 60 and 80 years of age found that BCG vaccination induces innate and adaptive immunity among them, which could prove beneficial against the SARS-CoV-2 virus. Researchers from the ICMR-affiliated National Institute for Tuberculosis Research (NIRT), Chennai, have found in an ongoing study that the BCG vaccine induces increased memory cell responses and complete development of antibodies among the elderly. "The BCG vaccination was associated with enhanced innate and adaptive memory cell subsets as well as total levels of antibodies in elderly people, indicating its possible usefulness in SARS-CoV-2 infection by enhancing heterologous immunity," the report, which is available in Wednesday's MedRxiv preprint journal for health sciences, said.
The Baceille Calmette-Guerin (BCG) is a heterologous vaccine in which a single pathogen is introduced to protect against different one. In this case, BCG is composed of Mycobacterium bovis and is used to protect against tuberculosis ( TB) caused by Mycobacterium tuberculosis bacteria. "As part of our clinical study to explore the effect of BCG on Covid-19, we investigated the influence of BCG vaccination on the frequencies of T cell, B cell, monocyte and dendritic cell subsets as well as total antibody levels in a community of healthy elderly people (ages 60-80 years) one month after vaccination," the ICMR researchers stated.
Researchers from all over the world have been trying to understand the promise of the BCG vaccine for Covid-19 infections ever since the outbreak of the Covid-19 pandemic. A group of US scholars who had conducted comprehensive global study of BCG vaccination, published in the Proceedings of the National Academic of Sciences (PNAS), had suggested earlier in June that 'BCG may have a protective impact in patients with Covid-19.' ICMR was inspired by the possible protective properties of the BCG vaccine for Covid-19 positive patients to initiate an Indian study to assess its efficacy among elderly people between the ages of 60 and 80 living in the country's Covid-19 hotspots.
The BCG research, led by NIRT, was conducted in six locations, including Tamil Nadu, Maharashtra, Gujarat , Madhya Pradesh, Rajasthan and New Delhi, with approximately 1,500 safe volunteers over 60 years of age. The BCG vaccine, which for the past 50 years has been part of the National Immunization Program in India, has been administered to older people who are not affected by Covid-19 disease. The ICMR research aimed to determine whether BCG shots can prevent infection with SARS-CoV-2 and whether it can prevent the virus from spreading and becoming a major cause of elderly morbidity. The BCG vaccine is basically the first vaccine to be given shortly after birth to practically all infants in India. Via observational studies, scientists from around the world have linked low Covid-related mortality rates in India and Pakistan to the practise of mandatory BCG vaccination.