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. By Sui-Lee Wee and Ernesto Londoño Scientists 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 […]