Video report by ITV News Science Editor Tom Clarke
The Prime Minister has defended the AstraZeneca vaccine after Germany ruled that it should only be recommended for under 65s.
Boris Johnson said he is not concerned by the ruling and insisted evidence show it “provides a good immune response across all age groups”.
A draft recommendation from Germany’s vaccination advisory committee said the jab should only be given to people aged 18 to 64 for now as there was 'insufficient data' to recommend it for those aged over 65.
Mr Johnson, during a visit to Scotland, said he does not agree with the German ruling, as he backed the advice from the UK’s Medicines and Healthcare products Regulatory Agency (MHRA).
He said: "I think that the MHRA, our own authorities, have made it very clear that they think the Oxford/AstraZenica 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 that they've supplied is that they think that it is effective across all age groups."
Boris Johnson explains why Germany's position does not cause him concern over the vaccine's efficacy
Dr Mary Ramsay, head of immunisations at Public Health England (PHE) has also defended the use of the jab.
She 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 “reassuring”.
Dr Ramsay said: “Both the AstraZeneca and Pfizer/BioNTech vaccines are safe and provide high levels of protection against Covid-19, particularly against severe disease.
“There were too few cases in older people in the AstraZeneca trials to observe precise levels of protection in this group, but data on immune responses were very reassuring.
“The risk of severe disease and death increase 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.”
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The European Medicines Agency is expected to approve the vaccine for use in the EU on Friday, although it is not yet clear whether it will set an age limit.
But the German authorities said: "There currently is not sufficient data to assess the vaccination effectiveness from 65 years."
Oxford University, which partnered with AstraZeneca to develop the vaccine, has stressed that its jab offers high protection against severe disease and prevents people needing to go to hospital.
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 4,088 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.
AstraZeneca and the vaccines minister Nadhim Zahawi dismissed the report as “incorrect” and “untrue”.
Meanwhile, Downing Street said the UK’s chief scientific adviser, Sir Patrick Vallance, had told the Cabinet that the Oxford/AstraZeneca vaccine had been shown to be effective in younger and older people.
A No 10 spokesman said: “The chief scientific adviser set out that the Oxford/AstraZeneca vaccine remains both safe and effective and that the trials showed similar immune responses in both younger and older adults.”
AstraZeneca said: “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.”
Some 7.9 million jabs have been given in the UK so far including 7,447,199 first jabs up to January 27 - a rise of 282, 812 on the previous day.
The seven-day average of first doses in the UK is now 353, 422 which is lower than the amount needed to meet the Government's target of 15 million first doses by February 15.
To reach this target, an average of 419,600 first doses of vaccine would be needed.