Experts say the relatively small number of people in the low-dose group makes it difficult to know if the effectiveness seen in the group is real or a statistical quirk. (File photo)AstraZeneca and Oxford University on Wednesday (Thursday, New Zealand time) acknowledged a manufacturing error that is raising questions about preliminary results of their experimental Covid-19 vaccine. In the low-dose group, AstraZeneca said, the vaccine appeared to be 90 per cent effective. READ MORE:* Covid-19: AstraZeneca to start rolling out hundreds of millions of doses of vaccine by Christmas* Covid-19: AstraZeneca vaccine 'highly effective' prevention* Coronavirus: Second Covid-19 vaccine shows overwhelming success in US tests* Coronavirus: What New Zealand is doing to get a Covid-19 vaccineDid researchers mean to give a half-dose? Another factor: None of the people in the low-dose group were over 55 years old.

Source: Stuff November 26, 2020 02:15 UTC