Oxford vaccine more effective with three-month gap between doses: study
AstraZeneca and Oxford University’s Covid-19 vaccine is more effective when its second dose is administered three months after the first, instead of six weeks, a peer-reviewed study published in The Lancet medical journal showed on Friday.
The study confirmed the Anglo-Swedish drugmaker’s findings from earlier this month which showed the vaccine had 76% efficacy against symptomatic coronavirus infection for three months after the first dose.
Efficacy was found to be 81% with the longer interval of 12 weeks between the first and second dose, compared with 55% efficacy which the six-week gap, according to The Lancet study, which backs British and World Health Organisation recommendations for longer intervals.
Faced with a resurgence in infections and new, highly transmissible variants of the coronavirus, many countries are hoping to broaden immunisation by giving some protection to as many people as possible with a first dose while delaying subsequent shots.