How a dosing error turned into lucky punch for AstraZeneca and Oxford

A stroke of good fortune from a dosing error will pave the way for AstraZeneca and Oxford University to submit their Covid-19 vaccine for regulatory clearance.

The British drugmaker said on Monday that the vaccine could be around 90% effective, when administered as a half dose followed by a full dose a month later, citing data from late-stage trials in Britain and Brazil.

"The reason we had the half-dose is serendipity," Mene Pangalos, the head of AstraZeneca's non-oncology research and development, told Reuters.

A larger group who had received two full doses - as planned - resulted in an efficacy read-out