AstraZeneca faces more Covid-19 vaccine questions after manufacturing error

Oxford said a difference in manufacturing processes led to later phases of the trials having a half-dose given instead of a full one

AstraZeneca Plc and the University of Oxford face mounting questions about their Covid-19 vaccine trial results after acknowledging a manufacturing error.
 

While an announcement earlier this week by Astra and Oxford showed their shot was 70 per cent effective on average in a late-stage study, the scant details released by the UK partners have sparked worries, with some expressing doubts about whether US regulators would clear it.

Astra and Oxford had said their vaccine was 90 per cent effective when a half-dose was given before a full-dose booster. Two full doses showed an efficacy of 62 per cent. But the