More evidence is emerging that the Oxford Covid vaccine works in older people, according to vaccine experts in the UK.
Sir Munir Pirmohamed, boss of the Commission on Human Medicines, today said regulators had received extra information from Oxford University and AstraZeneca scientists to prove their jab was safe and effective for over-65s.
The data, which is not yet publicly available, is coming now from same clinical trials in the UK and around the world that got it approved in the first place. They enrolled thousands more older people after the jab was green-lighted.
European leaders have ruffled the vaccine-maker’s feathers in recent weeks by claiming the vaccine doesn’t work on older people and refusing to use it.
In the same week that politicians were slinging mud at AstraZeneca for scaling back its deliveries, many European countries openly criticised the vaccine, with France’s President Macron calling it ‘quasi-ineffective’.
Oxford scientists hit back against the claims, with Professor Andrew Pollard saying he didn’t understand what Mr Macron’s comment meant. And the team behind the ground-breaking vaccine said the idea that it didn’t work had ‘no basis’.
Numerous countries including Spain, Germany, France, Hungary, Sweden and Norway have suggested they won’t give the jab to anyone over 65.
Scientists admit there is a lack of data definitively proving the vaccine works for elderly people but the data they do have suggests it doesn’t affect them any less than it does younger people, in whom it is proven to prevent Covid-19.
Oxford and AstraZeneca chiefs said this week that they expect data on effectiveness in over-65s – who were in the same study as other age groups but a couple of months behind – in the next few weeks.
It comes as another study published today by Oxford found that the vaccine works just as well against the fast-spreading Kent variant B.1.1.7 which is now dominant in the UK.
Oxford University and AstraZeneca’s vaccine has sparked criticism in Europe because its clinical trial didn’t enrol over-65s until later than other age groups so it doesn’t yet have the same level of proof that it will protect them from Covid-19. The researchers who made and tested the vaccines, and the drug regulators in the UK and EU as a whole, were satisfied that there is enough evidence to approve it, but some countries’ leaders are sceptical
Sir Munir said in a briefing today: ‘There was no evidence that those people over 65 were not getting evidence of efficacy.
‘Since then we’ve seen more data coming through from AstraZeneca as more people are completing the trial, which highlights again that efficacy in the elderly is seen, and there’s no evidence of lack of efficacy.’
The data Sir Munir refers to is not yet publicly available and has been sent directly to the MHRA, the UK’s vaccines regulator.
He added that elderly people were generating strong immune responses and said the most important thing was that both AstraZeneca’s vaccine and a jab developed by Pfizer and BioNTech were preventing serious disease and deaths.
Asked about the suggestion that Britain had compromised on safety and efficacy standards, MHRA chief executive, Dr June Raine, defended the regulator’s standards.
‘I think our position is very clear in terms of the rigorous science that MHRA pursues in the interests of public confidence, public safety, and the effectiveness of these important vaccines,’ she said.
Professor Andrew Pollard, the Oxford professor who is running the clinical trials of the jab, added: ‘It’s really for each country to take their own scientific advice… but it is authorised everywhere [in the European Union].’
He said: ‘The point about efficacy depends very much on how you cut the data.
‘You can cut it in different ways and get different data. That would be true of all vaccines in development.
‘But [these results] show it has a high efficacy in disease and we are not seeing a high accumulation of hospitalised cases in those who have been vaccinated.’
Boris Johnson previously said he was not concerned by the European countries’ move, adding the UK’s world-leading regulator had ‘made it clear’ the shot was ‘very good and efficacious’.
The issue that European countries have taken with the study is that the vaccine was only trialled on 660 people over the age of 65 in results that have been published so far.
A breakdown of the report showed that one out of 341 people who got the jab later tested positive for coronavirus. Meanwhile one in 319 people who got a fake jab, called a placebo, tested positive.
The whole point of a clinical trial is to compare the number of positive cases in the vaccine group to the number of positives in the non-vaccine group, to work out how well the jab works.
With the exact same number of cases in both groups and an almost identical number of participants, this is impossible to do.
A German analysis of the clinical trial of the vaccine, published on Twitter by a Berlin correspondent for The Times, showed that officials there estimated the efficacy of the vaccine to be just 6.3 per cent in over-65s.
To illustrate how unreliable the 6.3 per cent estimate is, experts in one German analysis of the study – which was shared on Twitter – included their confidence interval, which is a range of numbers they are almost certain the true number falls within.
The confidence interval suggests that scientists thought the true effectiveness of the vaccine in over-65s was somewhere between -1,405 per cent and 94.5 per cent. This means the estimate is wildly unreliable and a true figure cannot be calculated.
The data is the same that was used by the UK Government to approve the jab, and regulators in Britain admitted there was not enough data to give a percentage estimate of its efficacy – while the Germans attempted to do it anyway.
But they were satisfied by the fact that the vaccine was well-tolerated and safe in the older people who did receive it, and the fact that their immune response appeared in lab tests to be the same as those in younger people, who featured more heavily in the trial.
In short, the Medicines and Healthcare products Regulatory Agency (MHRA) said they would not expect the vaccine to work any differently in older people than in other age groups.
They said: ‘Efficacy and safety data are currently limited in individuals ≥65 years of age. No dosage adjustment is required.’
The study has enrolled more older people since it first reported results and continues to gather data on how the vaccine functions in that group.
The jab appears to be between 62 and 90 per cent effective in the adult population in general, according to Oxford University researchers.
And research published today showed that the vaccine appears to work just as well against the B.1.1.7 Kent variant of the coronavirus, which spreads faster than others.
The emergence of new variants across the world has sparked fears the virus may be able to dodge immunity triggered by the vaccines.
Some variants have changed the shape of their spike protein – which the virus uses to enter cells – to evade the immune system.
Virus-fighting antibodies bind to this to stop an infection occurring, but if the shape has been changed they are less likely to be able to bind and stop the virus.
Experts had been concerned over the Kent variant, but recent research has suggested it is susceptible to immunity from the current crop of jabs.
The Oxford study published today put those fears to bed and said: ‘Vaccine efficacy against symptomatic positive infection was similar for B.1.1.7 and non-B1.1.7 lineages.’
It found that the vaccine was able to block 84 per cent of cases of Covid caused by the old variant compared to 75 per cent of those caused by the Kent variant.
There are still concerns over the South African strain – with some studies showing jabs are less effective against it – and the Brazilian strain.
The Oxford group say they are currently testing their jab in South Africa on the variant, and are reviewing data to see whether they have any cases of the Brazilian variant from trials carried out in the country.