Disappointing Chinese Vaccine Results Pose Setback for Developing World

Disappointing Chinese Vaccine Results Pose Setback for Developing World

Brazil says CoronaVac has an efficacy rate just over 50 percent, much lower than previously announced. More than 380 million doses have already been ordered.Inspecting vials containing the CoronaVac vaccine, made by the Chinese company Sinovac, at the Butantan Institute in São Paulo, Brazil. Credit...Amanda Perobelli/ReutersBy Sui-Lee Wee and Ernesto LondoñoScientists in Brazil have downgraded the efficacy of a Chinese coronavirus vaccine that they hailed as a major triumph last week, diminishing hopes for a shot that could be quickly produced and easily distributed to help the developing world.Officials at the Butantan Institute in São Paulo said on Tuesday that a trial conducted in Brazil showed that the CoronaVac vaccine, manufactured by the Beijing-based company Sinovac, had an efficacy rate just over 50 percent. That rate, slightly above the benchmark that the World Health Organization has said would make a vaccine effective for general use, was far below the 78 percent level announced last week.The implications could be significant for a vaccine that is crucial to China's global health diplomacy. At least 10 countries have ordered more than 380 million doses of the Sinovac inoculation,