MILLIONS of vaccines meant for the UK could be blocked by the European Union as the so-called “vaccine war” intensifies.

The threat to continental supplies of the Pfizer jag to Britain came as Boris Johnson made clear he was not concerned by Germany ruling that the UKmade AstraZeneca vaccine should only be recommended for under 65s.

The Prime Minister, on a visit to Scotland to be updated on the vaccination programme north of the border, insisted the scientific evidence showed the AZ jag “provides a good immune response across all age groups”.

AstraZeneca has enraged the EU27 by admitting it can deliver only a quarter of the 100 million doses it had promised for the first quarter of the year. Production issues at European plants are being blamed but the bloc insists doses made elsewhere like Britain should make up the shortfall.

Political leaders across the bloc are coming under intense pressure as the rollout on the continent is much slower than in the UK.

Mr Johnson has insisted he is “very confident” of the security of the UK’s vaccine supply lines and Michael Gove, the Cabinet Office Minister, was adamant that there would be “no interruption” to deliveries to Britain.

However, the European Commission is expected on Friday to authorise new rules that would enable national regulators to refuse vaccine exports with 24 hours. The UK has ordered 40m doses of the Pfizer vaccine, which is produced in Belgium, and which forms a key part of the Government's attempt to get people in the four most vulnerable groups inoculated by February 15.

An EU official admitted: “There is a possibility in certain circumstances not to allow the export to come forward.”

Another explained: “We want to protect the doses that are supposed to accrue to our citizens, to our member states, via the advanced purchase agreements.”

On Wednesday, Stella Kyriakides, the bloc’s Health Commissioner told AstraZeneca that it was contractually obliged to send vaccinations produced in Oxford and Keele to EU member states.

“We reject the logic of first come first served. That may work at the neighbourhood butchers but not in contracts,” she declared.

Meanwhile, on his Scotland visit, Mr Johnson, asked if he was concerned about the verdict in Germany, said: “No, because the Medicines and Healthcare Regulatory Authority[MHRA], our own authorities, have made it very clear that they think the Oxford/AstraZeneca vaccine is very good and efficacious, gives a high degree of protection after just one dose and even more after two doses.

“And the evidence they’ve supplied is they think it’s effective across all age groups and provides a good immune response across all age groups.”

On Friday, the European Medicines Agency[EMA] is expected to approve the vaccine for use in the EU although it is not yet clear whether it will set an age limit.

However, the German authorities said: “There currently is not sufficient data to assess the vaccination effectiveness from 65 years.”

Dr Mary Ramsay, the head of immunisations at Public Health England, acknowledged there had been “too few cases” of coronavirus in older people in Phase 3 clinical trials to determine the level of efficacy in this age group, but said other data on immune response had been “very reassuring”.

She insisted the vaccines were safe and provided “high levels of protection” against Covid-19 and “particularly against severe disease”.

Dr Ramsay pointed out the risk of severe disease and death increased exponentially with age. “The priority is to vaccinate as many vulnerable people as possible with either vaccine, to protect more people and save more lives.”

Oxford University, which partnered with AstraZeneca to develop the vaccine, has stressed that its jag offers high protection against severe disease and prevents people needing to go to hospital.

AstraZeneca said in a statement: “The latest analyses of clinical trial data for the AstraZeneca/Oxford Covid-19 vaccine support efficacy in the over 65 years age group. We await a regulatory decision on the vaccine by the EMA in the coming days.”

Professor Andrew Pollard, Director of the Oxford Vaccine Group, pointed to the MHRA’s report, which said there were two cases of Covid-19 in the over-65s.

The MHRA said: “There is limited information available on efficacy in participants aged 65 or over, although there is nothing to suggest lack of protection.”

A Phase 3 Lancet study published in December said older age groups had been recruited later into the study so “efficacy data in these cohorts are currently limited by the small number of cases, but additional data will be available in future analyses”.

In that particular analysis, only 12% of people given two doses of the vaccine in the UK arm of the trial[285 out of 2,377] were aged 56 to 69, while 9%[213] were over 70.

Some 12% of people in the control group, given a dummy vaccine, were also aged 56 to 69 while 9% were over 70.

Older people made up similar proportions in the Brazilian section of the trial, which was made up of more than 4,000 people.

Previous work published in November included findings for 560 people. Of these, 160 were aged 18 to 55, 160 were aged 56 to 69, and 240 were 70 or older.

Those results found that all age groups, including older people, had an immune response to the vaccine after two doses.

Earlier this week, a report in German business daily newspaper Handelsblatt said AstraZeneca’s vaccine was thought to be only 8% effective among the over-65s.

But AstraZeneca and Nadhim Zahawi, the UK Government’s Vaccines Minister, dismissed the report as “incorrect” and “untrue”.