Covid-19 vaccines for that can provide immunity to at least 50% of the participants in phase clinical trials, according to a Mint report.The development comes in the backdrop of both World Health Organisation's and US Food and Drug Administration’s benchmarks that says that a coronavirus vaccine must prove to be at least 50% more effective than a placebo in a large-scale trial to be considered for approval.Here are the major developments on the manufacturing and clinical trials of Covid-19 vaccines in India:Click here to read the Mint ePapermint is now on Telegram.