The independent commission advising the German government on vaccination policy has recommended that the Oxford/AstraZeneca vaccine not be used for people aged over 65, in a move likely to complicate the acrimonious rollout of the jab in the EU.

A statement by the Standing Vaccine Commission at the Robert Koch Institute, Germany’s main public health agency, said there were “insufficient data currently available to ascertain how effective the vaccination is above 65 years”.

For that reason, the commission said it was recommending that the vaccine only be used on people aged between 18 and 64. It added that the two shots already approved by the European Medicines Agency — from BioNTech/Pfizer and Moderna — were judged to be “equivalent in terms of safety and efficacy”. The EMA is expected to reach a long-awaited decision on the approval of the Oxford/AstraZeneca vaccine for use in the EU on Friday.

According to a set of trial data released by the German vaccine commission, just two of 660 trial participants over the age of 65 got Covid-19 — one in the vaccinated and one in the control group — which is far below the number needed to draw statistical conclusions. That set of trial data showed an overall efficacy of 70.4 per cent.

AstraZeneca rejected the German recommendation, saying the latest analysis of the clinical trial data for the vaccine supported efficacy in the over-65 age group.

“We await a regulatory decision on the vaccine by the EMA in the coming days,” it said.

London-listed shares in the drugmaker fell as much as 2.4 per cent after the news.

The German recommendation came with EU and AstraZeneca locked in a crisis over vaccine supplies, after Brussels attacked the company’s “continued lack of clarity” on its delivery schedule.

While both the EU and AstraZeneca said high-level emergency talks held on Wednesday night had been “constructive”, they did little to resolve the dispute over whether the company should deliver tens of millions more doses to the EU than it plans to over the first three months of the year.

France and Italy both said they would wait for the EMA decision on Friday, before taking a view on whether to recommended the shot for the elderly.

Emer Cooke, head of the EMA, said on Wednesday that there was no indication that it would need to restrict use of the jab based on age, but said she did not want to prejudge any outcomes.

The EMA declined to comment on the German recommendation, pointing instead to a statement it made earlier on Thursday, saying it was still evaluating the vaccine.

“We expect the committee’s recommendation on the authorisation of this vaccine tomorrow, on 29 January, and will communicate the assessment and its outcome shortly after the opinion has been adopted,” it said.

Germany’s move could raise questions in the UK, where the vaccine is approved for all persons aged 18 and over. When the UK regulator, the Medicines and Healthcare products Regulatory Agency (MHRA), approved it for emergency use last month, health authorities acknowledged there was a small amount of data on older populations, but that more results would become available this year.

The MHRA did not immediately respond to a request for comment.

Additional reporting by Miles Johnson in Rome and Leila Abboud in Paris