With trials of Sinovac Biotech Ltd.’s coronavirus vaccine in Brazil and Turkey suggesting the shot has a protection rate on either side of 90%, there is still no final assessment on exactly how effective it is in protecting people against Covid-19.
Sinovac is finalizing results of phase III trials carried out in Brazil, Turkey, Indonesia and Chile, according to a person familiar with the trials. Those tests are relatively independent from each other and conducted according to different protocols, rather than subject to unified norms that typically govern such trials, said the person, who asked not to be identified because the data isn’t public.
Researchers in Brazil earlier this week delayed releasing complete information on Sinovac’s vaccine, saying only that it was found to be more than 50% effective. Sao Paulo state Health Secretary Jean Gorinchteyn offered more specific guidance on Thursday, saying the vaccine “didn’t reach 90%” efficacy, which would make it less successful than those developed by Pfizer Inc. and Moderna Inc.