Third wave of coronavirus unlikely to be as severe as second wave: Study SECTIONS Last Updated: Jun 26, 2021, 10:00 AM IST Share Synopsis Considering the four hypotheses for the emergence of a third wave, the study said, infection-induced immunity may decay over time, permitting re-infection of those previously exposed, even if the circulating virus remains unchanged. Covid third wave 'unlikely to be as severe' as the second wave: ICMR study A third wave of COVID-19 -- if it occurs -- is unlikely to be as severe as the second wave given the extent of spread of coronavirus infections that has already taken place in the country, according to a study. The study, based on mathematical modelling analysis published in the Indian Journal of Medical Research (IJMR), highlights that the emergence of a third wave of coronavirus could be substantially mitigated by the expansion of vaccination.