The Oxford University/AstraZeneca vaccine is coming under increasing scrutiny, with critics questioning the claim that trials showed it could protect up to 90% of people against coronavirus.
On Thursday Sir John Bell, Oxford’s regius professor of medicine and the UK government’s life sciences adviser, dismissed suggestions the trial had not been properly set up or reported. “We weren’t cooking this up as we went along,” he said, adding that he hoped the full, peer-reviewed data would be published in the Lancet medical journal at the weekend.
In spite of the public excitement generated by the announcement that a third vaccine had been successful – with particular promise for developing countries as it is relatively cheap and can be stored at fridge temperature – AstraZeneca’s share price dropped.
One analyst in the US wrote in an investor note that “we believe that this product will never be licensed in the US” and alleged the company had tried to “embellish” the results.
It comes after the headline figure for the vaccine’s overall efficacy was put at 70% – as announced by the company on Monday and discussed in a press briefing by the Oxford researchers. But a sub-set of fewer than 3,000 people in the UK was given a lower dose regime – originally by accident – where the efficacy rose to 90%. In most trial volunteers in Brazil and the UK, it was 62%.
Sir Mene Pangalos, AstraZeneca’s head of biopharmaceuticals R&D, has confirmed that the low-dose trial included nobody over the age of 55. This led to concerns that younger age may have been a factor – particularly relevant given that the vulnerable elderly are most at risk from Covid-19.
Researchers had no explanation for the 90% result in people given a half dose followed by a whole dose of the vaccine, instead of two whole doses in other arms of the trial. Critics claimed the trials did not include enough ethnic diversity, gender and age balance to satisfy the US regulator, the Food and Drug Administration.
Defending the vaccine trials, Bell told a symposium run by the Faculty of Pharmaceutical Medicine: “[The] MHRA [Medicines and Healthcare Products Regulatory Authority] knew perfectly well what we were doing. They approved all the protocols.”
It had been widely accepted before any of the vaccine trials reported results that 60% efficacy would be enough for a licence and would be useful, he said. “We are well in excess of that. I can’t imagine any reason why regulators won’t accept that.”
America had not yet seen the full data, he said, which he hoped would be published in the Lancet at the weekend. “I think when they see the data, it will be a great deal easier to have these conversations.”
Scientists at Oxford and the company admitted they were surprised