COVID SCIENCE UPDATE

Oxford/AstraZeneca vaccine might work better with doses months apart

Among recipients of the COVID-19 vaccine from Oxford University and AstraZeneca, prolonging the interval between the first and second doses led to better results, researchers said in a paper posted on Monday ahead of peer-review by The Lancet on its preprint site.

For volunteers aged 18 to 55, vaccine efficacy was 82.4% with 12 or more weeks between doses, compared to 54.9% when the booster was given within 6 weeks after the first dose.

The longest interval between doses given to older volunteers was 8 weeks, so there were no data for the efficacy of a 12-week dosing gap in that group.

Europe's medicine regulator has said there is not enough data to determine how well the vaccine will work in people over 55.

Given their findings, the authors say "a second dose given after a three-month period is an effective strategy ... and may be the optimal for rollout of a pandemic vaccine when supplies are limited in the short term." -- Reuters