A new study by the ICMR is set to find the utility of BCG vaccine in reducing severity of COVID-19. BCG vaccination prevents severe forms of tuberculosis in children.
The ICMR-National Institute for Research in Tuberculosis in Chennai has initiated a multi-centric study to investigate whether Bacille Calmette Guerin (BCG) vaccine can prevent and/or reduce the severity of COVID-19 disease among elderly individuals aged 60 years and above residing in hotspots for SARS-CoV2.
According to ICMR, the study will be carried out in six states—Tamil Nadu, Maharashtra, Gujarat, Madhya Pradesh, Rajasthan and Delhi in approximately 1,000 healthy volunteers who are above 60 years of age. “In Tamil Nadu, it will be done in close collaboration with the Greater Chennai Corporation and state department of public health,” according to ICMR.
The study will also document whether BCG vaccine can prevent the occurrence of the SARS- CoV-2 infection and its progression and death associated with COVID-19 among the elderly. “The study uses the same BCG vaccine that is administered to newborn babies as a part of national immunisation programme for over 50 years. There are pre-set criteria in the study that will decide on eligibility of a volunteer to participate in this study. The study would enroll approximately 1000 participants and follow them closely for a period of six months post vaccination,” according to ICMR.
“BCG vaccine shall be administered on trial basis for adults aged 60-95, ordered by Hon’ble Chief minister of Tamil Nadu. This is aimed at reducing COVID mortality rate in senior people. National Institute for Research in Tuberculosis will start the pilot program soon,” Dr C. Vijayabhaskar, state health minister, Tamil Nadu has tweeted earlier in the week. The trial is a non-randomised, active controlled trial.
The immunomodulatory properties of the BCG vaccine might have a protective effect in respiratory infections, but until the results of the randomised trials come in, it may not be prudent to read any more into its role in COVID-19, experts including the WHO director general, Dr Tedros Adhanom Ghebreyesus have cautioned. In an article in Lancet, experts including the WHO chief have said that the underlying mechanisms with vaccines such as BCG are now understood — the BCG vaccine and some other live vaccines induce metabolic and epigenetic changes that enhance the innate immune response to subsequent infections, a process termed trained immunity. Based on that, the vaccine may reduce viraemia after SARS-COV-2 exposure, with consequent less severe COVID-19 and more rapid recovery.
However, until RCT results are out— trials are on in Australia and Netherlands—the world needs to wait, experts caution.
