A vaccine, used to treat tuberculosis since the last 100 years, may help prevent the risk of Covid-19 infections in older adults, according to a study by the Indian Medical Research Council (ICMR). Bacillus Calmette-Guerin (BCG) is considered to be one of the most broadly used vaccines in the world, with around 130 million infants receiving this vaccine every year. There is improved interest in BCG vaccination of elderly population, especially in countries with a high number of reported Covid-19 cases.

Previous studies have reported that BCG vaccination may confer protection against respiratory tract infections, involving viral infections. The new study, published in the journal Science Advances, suggests that BCG could potentially act to inhibit the biomarkers of inflammation by the immune cells in the blood. However, "this remains to be proven. In addition, it is still unknown as to how long this inhibitory effect can persist", said a team of researchers from the ICMR-National Institute for Research in Tuberculosis and the ICMR-National Institute of Epidemiology.