LONDON (Reuters) – The University of Oxford’s COVID-19 vaccine candidate has a better immune response when a two full dose regimen is used instead of a full dose followed by a half dose booster, the university said Thursday, under reference to early trial data.
The developers of the vaccine candidate, licensed to the pharmaceutical company AstraZeneca, have already published later-stage study results showing higher efficacy when half a dose is followed by a full dose, compared to a regimen of two full doses. doses. However, more needs to be done to confirm that result.
The latest details of the Phase I and 2 clinical trials released Thursday did not refer to the half-dose / full-dose regimen, which Oxford said was “unplanned,” but approved by regulators.
Once seen as the front runner in the development of a coronavirus vaccine, the British team has been overtaken by American drug company Pfizer, whose shots were rolled out in Britain and the United States this month.
Previously published data from the later phase 3 studies showed that the efficacy was 62% for subjects who received two full doses, but a more robust 90% for a smaller subgroup who received a half and then a full dose.
In its statement on Thursday, the university said it had explored two dosing regimens in early-stage studies, a full dose / full dose regimen and a full dose / half dose regimen, explored as a potential “dose-saving” strategy.
“The booster doses of the vaccine have both been shown to elicit stronger antibody responses than a single dose, with the standard / standard dose eliciting the best response,” the university said in a statement.
The vaccine “stimulates broad antibody and T cell functions,” he said.
Reporting by Alistair Smout and Keith Weir; Edited by William James, Mark Heinrich and Frances Kerry