Participants given first shot at half strength by mistake were found to be better protected
The Oxford University and AstraZeneca vaccine trials reached 90% efficacy by accident thanks to the “serendipity” of an error that led to some participants receiving half doses, it has emerged.
On Monday scientists revealed that the Oxford vaccine had an overall efficacy of 70%, but could be around 90% effective when administered as a half dose followed by a full dose a month later.
