Chinese Sinovac covid vaccine more than 50% effective, but data withheld

A Covid-19 vaccine developed by Chinese pharmaceutical firm Sinovac Biotech Ltd. was found to be more than 50% effective in a Brazilian clinical trial, though researchers delayed releasing more information at the request of the company. A 50% efficacy rate is a minimum standard set by US regulators for emergency authorization of Covid vaccines. Messenger RNA vaccines from Moderna Inc. and Pfizer Inc. have produced far better results, reducing symptomatic Covid cases by well over 90% in giant trials. MORE FROM THIS SECTIONSee All How Oxford- AstraZeneca covid-19 vaccine went from pole position to troubled start 12 min read . 04:23 PM IST Mutated Covid-19 strain’s transmissibility to cause...