Third wave possible if vaccination not ramped up, Covid norms not followed: Scientist PTI New Delhi | Updated on May 20, 2021 × The IIT-Hyderabad professor and Sutra Model scientist cited a paper by Italian researchers on infected people with falling antibodies that give immunity for six months If the vaccination drive against coronavirus is not ramped up and Covid-19-appropriate-behaviour is not maintained, there is a possibility of a third wave of the pandemic in six-eight months, said M Vidyasagar, a scientist involved in the Sutra Model which uses mathematics to project the trajectory of Covid-19. He, however, stressed the Sutra Model has not predicted any third wave and it is working on it.