Disappointing Chinese Vaccine Results Pose Setback for Developing World January 13, 2021 +4 Brazil says CoronaVac has an efficacy rate just over 50 percent IFTTT much lower than previously announced. More than 380 million doses have already been ordered. NYT NYT > Business NYTimes Brazil says CoronaVac has an efficacy rate just over 50 percent IFTTT much lower than previously announced. More than 380 million doses have already been ordered. NYT NYT > Business NYTimes