India has bought 1.6 billion doses of Covid-19 vaccines, which is more than any other country, according to a global analysis. Using its massive manufacturing clout, the country purchased 500 million doses of the Oxford University-AstraZeneca vaccine candidate, one billion from the American company Novavax and 100 million doses of the Sputnik V candidate from Russia's Gamaleya Research Institute, said the USA-based Duke University Global Health Innovation Centre.