Two doses of the Covishield vaccine provided 63% protection against symptomatic COVID-19 infection and 85% protection against moderate or severe disease, suggested a study conducted in Faridabad, Haryana. The study was carried out during the second wave when the Delta variant dominated.

The study suggests that the vaccines continued to be effective at protecting against severe disease and death irrespective of the variants. The findings from the study, published online in Lancet Infectious Diseases, are comparable to the results of recent studies conducted in England and Scotland that found the vaccine to be 60-67% effective against infection with the Delta variant.

The study assessed 2,379 confirmed cases and 1,981 healthy individuals. Around 3.6% of the cases were fully vaccinated compared to 8.5% of the controls. Of 84 cases with moderate-to-severe COVID-19 infection, only one was completely vaccinated, compared to 84 of 2,295 cases with mild disease. There were 16 deaths in the unvaccinated or incomplete vaccination group but zero deaths were reported in the completely vaccinated group… (The Hindu, November 26, 2021)