Clinical trials in Brazil have shown China’s Sinovac vaccine, called CoronaVac, to be only 50.4% effective against Covid-19, and not 78.4% effective, as had initially been claimed. Brazil had agreed to buy 100 million doses of CoronaVac, despite Brazilian President Bolsonaro’s initial criticism of the vaccine. Brazil has had 8.2 million cases of Covid-19 amongst […]