An ICMR study states that 2 Covid vaccine doses were successful in preventing 95% deaths due to Covid-19 during the second wave. Deaths were also lower by 82% among those inoculated with one dose, said the study. The ICMR conducted the study among more than 1.2 lakh police personnel, who were at high risk of infection, in Tamil Nadu. The study was conducted during the second wave which was mostly driven by the spread of the Delta variant.