China’s Covid Shot Has Four Wildly Different Efficacy Rates

China’s Covid Shot Has Four Wildly Different Efficacy Rates

Days before a global rollout kicks off with the President of Indonesia receiving the Sinovac Biotech Ltd. vaccine on live television, uncertainty swirls over the efficacy of the leading Chinese shot, for which four different protection rate numbers have been released in recent weeks.

Indonesia, which is moving the fastest on distributing the Sinovac shot to its population, said that a local trial showed an efficacy of 65% against Covid-19. But only 1,620 people in Indonesia took part in that trial — too small for meaningful data.

Turkey said last month that the same vaccine showed efficacy of 91.25% in its local trial, which was similarly too small to draw a sufficient conclusion.

In Brazil, where Sinovac’s biggest trial of more than 13,000 people is being conducted, dueling efficacy rates have been publicized. The company’s local trial partner, Butantan Institute, said last week that the vaccine was 78% effective in preventing mild cases of Covid-19 and 100% effective against severe and moderate infections.