WASHINGTON, United States (AFP) — AstraZeneca’s Covid-19 vaccine is 80 percent effective at preventing the disease in the elderly and does not increase the risk of blood clots, the biotech firm said Monday, following its US phase III efficiency trials. It was 79 percent effective at preventing symptomatic Covid-19 in the overall population and 100 percent effective at preventing severe disease and hospitalization, it said. Several countries had advised against administering the jab to […]