The study by Oxford University investigated the ability of monoclonal antibodies in Sera from recovered people and from vaccinated people to neutralize the Delta and Kappa variants, the statement said.
The trial results, primarily generated in the United States but also in Chile and Peru, included a 79% efficacy in preventing symptomatic COVID-19, and showed no increased risk of a rare form of blood clots that has caused concern in parts of Europe.
Britain's Medicines and Healthcare products Regulatory Agency concluded at the time that a 12-week gap between doses was the key to achieving the highest efficacy, of around 80%.
Indian health officials say they generally ask for so-called bridging trials to determine if a vaccine is safe and generates an immune response in its citizens whose genetic makeup can be different from people in Western nations.
Earlier in January, Pfizer, which is currently the largest supplier of COVID-19 vaccines to the EU, announced delays of nearly a month to its shipments, but hours later revised this to say the delays would last only a week.