Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK
The Lancet
AstraZeneca vaccine: Findings from the interim analysis of the randomized trials of the AstraZeneca–University of Oxford vaccine have now been published in The Lancet. As previously reported, the adenovirus vaccine showed 62% efficacy among people who received two full doses and 90% efficacy among those who received a half-dose followed by a full dose. The half-dose was given inadvertently to a subset of U.K. participants. Commentators write, “Public concerns might have been raised by the unplanned administration of different doses, notwithstanding that the per-protocol primary results exceeded licensure thresholds and that the serendipitous findings for recipients of the mixed-dose regimen were of high efficacy.” They call for additional research into the findings with the mixed-dose regimen.
The Lancet article on AstraZeneca-Oxford vaccine