Extra trial for Oxford vaccine to prove its protection of elderly

The drug company behind one of the UK’s leading vaccines is to run an extra trial amid growing questions about its performance.

On Tuesday, scientists from Oxford University and AstraZeneca revealed their vaccine had achieved an overall efficacy rate of 70 per cent in phase III trials. However, this rose to 90 per cent in a sub-group.

It was disclosed that this had stemmed from an error, when some of those in the study were given half a dose for the first jab, when a full dose was intended. Those given the intended dose saw efficacy rates of just 62 per cent.

Yesterday, the company said it would run extra trials, to satisfy regulators, after US health officials announced that no-one in the group with 90 per cent efficacy rates was above the age of 55.

The revelation sparked widespread concern, because the jabs will be targeted at the elderly first.

However, British scientists pointed out that previous trials suggested the vaccines were highly effective in the elderly. Yesterday, the government confirmed that Professor Jonathan Van-Tam, deputy chief medical officer for England, had asked the Medicines and Healthcare products Regulatory Agency to begin processes to evaluate the safety and efficacy of the vaccine.

It is hoped that the jab roll-out could start next month.

The UK has bought 100 million doses, with hopes that almost 20 million of them will be available for use by the end of the year.

The head of AstraZeneca said the company would run an extra study, in order to validate the findings from the sub-group.

While the study of those given two full doses involved 8895 people, the 90 per cent efficacy was based on a dosing regime given to 2741 people.

Pascal Soriot, the chief executive, said: ‘‘Now that we’ve found what looks like a better efficacy we have to validate this, so we need to do an additional study.’’ He said he did not expect the additional trial to hold up regulatory approvals in the UK.

Scientists from Oxford University yesterday said that previous phase II trials had shown the vaccines were ‘‘very, very effective in the elderly’’ insisting full data, which is about to be submitted to The Lancet medical journal, would reassure the public.

‘‘Now that we’ve found what looks like a better efficacy we have to validate this, so we need to do an additional study.’’

Pascal Soriot

AstraZeneca