India is the largest buyer of COVID-19 vaccines in the world with 1.6 billion doses, according to a global analysis. A number some scientists say could cover 800 million people or 60% of its population, and will be enough to develop 'herd immunity'. The 'Launch and Scale Speedometer' analysis, which is updated every two weeks, shows India has confirmed 1.6 billion doses of three vaccines as of November 30 while the US and the European Union have purchased doses of six candidates.