Covid Working Group chief Dr NK Arora has said that according to research in India, a single shot had up to 61 per cent effectiveness against the Delta strain, while 2 doses provide 65% protection.
Arora said the study was conducted “in the middle” of the second wave of the pandemic, which was majorly caused due to the B.1.617, or Delta variant, first detected in India.
Besides the vaccine efficacy quoted by Arora, the study also showed that one dose of the Covishield shot reduced the risk of hospitalization by 70% and two doses by 77%.