AstraZeneca’s Covid-19 vaccine, which is being used in Sri Lanka as well, was shown to be safe and 79% effective in preventing symptomatic disease in widely anticipated US clinical trials, the Wall Street Journal reported today. It said these results would provide a vote of confidence for the shot and a pathway for its authorization in the US The interim trial data showed the vaccine, developed in partnership with the University of Oxford, was 80% effective in participants aged 65 and over, a group previous AstraZeneca trials lacked in large numbers.