Confusion over efficacy emerged after interim late-stage trial results announced in late November when AstraZeneca acknowledged that people in its clinical trial accidentally got different doses.
Administration of the vaccine was paused in many parts of the world as regulators investigated the clots, concluding they were a very rare side effect β impacting about 86 people out of the 25 million who had received the vaccine.
It can be kept in a standard refrigerator for six months.