Britain on Friday asked its regulatory agency to review safety and efficacy data on AstraZeneca’s COVID-19 vaccine as experts have raised concerns on errors made in the drugmaker’s trial.
According to Reuters, the British government has purchased 100 million doses of the vaccine, developed by AstraZeneca in partnership with Oxford University, and AstraZeneca expects that about 4 million doses will be available in the U.K. by the end of December.
“We have formally asked the regulator to assess the Oxford/AstraZeneca vaccine, to understand the data and determine whether it meets rigorous safety standards,” said Health Secretary Matt Hancock, who has said he hopes the U.K. will begin distributing the vaccine before Christmas.
“This letter is an important step towards deploying a vaccine as quickly as safely possible,” Hancock added, according to Reuters.
Britain’s Medicines and Healthcare Products Regulatory Agency (MHRA) had begun earlier this month an accelerated “rolling review” of the AstraZeneca vaccine as data became available.
However, AstraZeneca and Oxford admitted Wednesday that a sub-group of trial participants were initially mistakenly given a half dose followed by a full dose.
This, combined with the fact that there was a relatively small number of participants when compared to other studies, has prompted questions among experts on the accuracy of the findings.
On Monday, AstraZeneca announced that its vaccine was, on average, 70 percent effective in preventing COVID-19, with two full doses given at least a month apart showing to be just 62 percent effective, while a half dose followed by a full dose appears to have a 90 percent efficacy rate.
AstraZeneca CEO Pascal Soriot said Thursday that the company would likely hold an additional global trial to test the effectiveness of its candidate vaccine using the half dose followed by the full one, Reuters reported.
This comes as Pfizer, whose vaccine candidate was found to be 95 percent effective in clinical trials, announced last week that it had officially applied for emergency use authorization from the U.S. Food and Drug Administration (FDA).
Operation Warp Speed officials told reporters Tuesday that should Pfizer’s vaccine receive FDA approval, an estimated 6.4 million doses will be distributed to states and territories by mid-December.
However, Health and Human Services Secretary Alex Azar added at the time that health care workers, people living in nursing homes and other vulnerable people should be first in line to receive the vaccine before it is widely available to the general public.
Moderna, which announced recently that its COVID-19 vaccine is 94.5 percent effective, is expected to file a request for emergency use authorization in the coming weeks.