A MedPage Today article reports that as Great Britain continues to stretch out the interval between the first and second doses of the COVID-19 vaccine to 12 weeks, data out this week seems to support doing so, but concerns remain. A study published in The Lancet showed that the AstraZeneca/Oxford vaccine provides sustained protection of 76% during the 12-week interval between first and second doses, however, clinical trials used to authorize the Pfizer/BioNTech and Moderna vaccines didn’t examine whether such a lag between first and second doses would have an impact on efficacy.

Helen Salisbury, a general practitioner and honorary senior clinical lecturer at the University of Oxford said that “the AstraZeneca/Oxford vaccine had another set of timelines built into trialing it, looking at longer gaps between first and second shot and now individual receiving first doses of other vaccines are doing so with the understanding that their second dose will be given 12 weeks later.” “If our best guess” is that the pandemic will end sooner by spacing out doses, helping to address shortages and vaccinating more people at 76% efficacy rather than fewer people with slightly better protection, that’s likely the right thing to do, so far the data is looking relatively good”.

The U.S. isn’t rushing to follow suit. Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, addressed the U.K.’s strategy of delaying doses during a White House COVID-19 Response Team briefing. “We have heard from studies emanating out of the AstraZeneca platform, that in the U.K. they’re talking about the possibility since their data seems to show this, that if you prolong the interval between the first and second dose, in fact even go with a single dose, you can get good results”. “ What is in the future is anyone’s guess but seriously, great information and hopefully will provide us with more insight into this virus! Stay well, mask up indoors, and stay tuned!