AstraZeneca US phase III vaccine trial shows 79% efficacy in preventing symptomatic cases

AstraZeneca publishes the data from a study of more than 30,000 volunteers

The vaccine was also shown to be 100% effective at preventing severe disease, death and hospitalisation. So, that is arguably the more important statistic.
In any case, this should bolster the approval process for the vaccine in the US – which may help to ease some of fears about the efficacy and use as debated in Europe lately.