A coronavirus vaccine developed by China's Sinovac Biotech was 78% effective in a late-stage Brazilian trial with no severe COVID-19 cases, researchers said on Thursday, although a lack of data details stirred calls for more transparency.
Brazil made a diplomatic push on Monday to guarantee an Indian-made shipment of British drugmaker AstraZeneca's COVID-19 vaccine, hoping to avoid export restrictions that could delay immunizations during the world's second-deadliest outbreak.