A study of COVID-19 vaccine immunity highlights the importance of vaccination in those who have already been exposed to the virus.
The study has found that both COVISHIELD and COVAXIN significantly enhance immune responses in subjects with varying levels of basal immunity to SARS CoV-2 developed through natural exposure. The multi-centric study led by researchers from St John’s Research Institute was published in npj Vaccines, a Nature journal on September 14.
COVISHIELD, manufactured by Serum Institute of India and COVAXIN, indigenously developed by Bharat Biotech Ltd were the first two vaccines authorized for COVID-19 vaccination in India. Even though India had a highly successful vaccination campaign, a majority of the population remained unvaccinated till end of 2021. A major question raised and unknown at that time was whether COVID vaccines available in India in 2021 were even capable of inducing immune responses over and above immunity that may have been acquired through natural exposure to the virus during the ancestral and Delta waves.
