The team behind the Oxford/AstraZeneca Covid vaccine have "no idea" when the jab will be approved by the British regulator, a scientist leading the research has said.
Data for the vaccine, developed with pharmaceutical giant AstraZeneca, has been submitted to the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) for approval.
But Dr Sarah Gilbert, professor of vaccinology at the University of Oxford, said she did not know when the MHRA could draw its conclusions about the vaccine.
“It’s actually AstraZeneca, the manufacturers of the vaccine, who are working directly with the regulators and in parallel. We have been working on the publication of the full data which came out yesterday,” she told the Today programme.
Dr June Raine, chief executive of the Medicines and Healthcare products Regulatory Agency (MHRA), said she was not able to give a "firm date" on when the review of the Oxford/AstraZeneca vaccine would be completed. "The data packages for the AstraZeneca/Oxford vaccine have been arriving, we do expect a further package in the coming days," she told the Commons Science and Technology and Health and Social Care committees. She added: "There will be questions and deliberations that we will be pursuing in exactly the same way as we have done for Pfizer/BioNTech. "So, not able to give a firm date, but to assure the committees that work is proceeding intensively and with great scientific rigour."
The Oxford/AstraZeneca Covid vaccine has been found to be safe and effective, researchers confirmed on Tuesday in a study published in The Lancet journal, but added more detail was needed on how effective the vaccine is for older adults.
Interim results from pooled studies show the vaccine was 70.4% effective on average in preventing coronavirus after two doses were given.
For people given two full doses of the jab in one study, the vaccine was 62.1% effective.
But in a study where people received a half dose followed by a full dose, the vaccine was 90% effective.
The overall efficacy of 70.4% is based on 11,636 volunteers across the UK and Brazil, and combined across three groups of people vaccinated.
Asked if the statistics paint the Oxford vaccine in a “slightly worse light” compared with others, Dr Gilbert said: “Well, that’s something that will become clearer over time.
“We’re all working out how to do this as we go along through this year and trying to make the best decisions quickly.
“And each trial should be considered on its own, rather than being compared to other trials.”On the smaller subgroup in the Oxford vaccine trial – the group who were given a half dose followed by a full dose – Dr Gilbert said: “It does appear to have higher efficacy, based on the data that we’ve got – as you say the subgroup is smaller than the subgroup that received two full doses of the vaccine.”
She told the Today programme: “What we need to do now is to look into the immune responses and people who’ve got the different vaccination regimens and see if we can find an explanation for that and that’s something that we should be able to do.”
Dr Gilbert said there were no older adults in that subgroup.
She added: “In fact, in the whole trial we haven’t had many cases of Covid disease in older people because they were recruited later into the trial.
“So the data that’s analysed so far was collected by the beginning of November, and in the next data analysis it’s likely there’ll be more inclusion of people over the age of 55.”
The team has measurements on the immune response in older people, she said, adding: “It doesn’t decline at all in people – even over the age of 70 there was no difference in their immune response.”
This means the MHRA could support licensing the vaccine for the elderly, she confirmed.