Sinovac Biotech Ltd. was 78% effective against Covid-19 in late-stage trials in Brazil, the most definitive result so far on the shot’s efficacy after previous data sparked confusion and doubt.The protection rate, confirmed by Sao Paulo state officials, was derived from Sinovac’s most advanced final-stage trials in Brazil involving about 13,000 participants.
The rate is shy of the roughly 95% effectiveness seen in mRNA vaccines developed by Pfizer Inc. and Moderna Inc.The vaccine was 78% effective in preventing mild cases of Covid-19 and 100% effective against severe and moderate infections, said Dimas Covas, director of the Butantan Institute that partnered with Sinovac to produce the shot locally.