Prognosis

CoronaVac’s Overall Efficacy in Brazil Measured at 50.4%

  • New numbers add to confusion over Chinese-developed vaccine
  • 78% rate presented last week had excluded very mild cases

   

Photographer: Jonne Roriz/Bloomberg
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Brazil officials said the CoronaVac vaccine developed in partnership with Sinovac Biotech Ltd was 50.38% effective in preventing coronavirus cases, a number that meets the threshold required by global regulators for approval but that’s well below the 78% figure announced last week.

At a press conference Tuesday, Sao Paulo state officials and researchers from Butantan Institute explained that they split the cases in six categories: asymptomatic, very mild, mild, two levels of moderate, and severe -- the first two not requiring medical assistance.