Ministers conceded this week that there will be a slowdown of the UK Covid vaccination programme after it emerged that fewer doses would be available in April than previously expected.
The UK government insists it is still on track to meet its headline targets.
But there are still unanswered questions about the supply of vaccines coming into the country.
Why the shortfall in April?
Matt Hancock gave a press conference on Wednesday in which he announced “fantastic news… on the success of the vaccination rollout”.
The Health Secretary did not make any reference in his opening remarks to imminent problems with the supply of Oxford/AstraZeneca vaccine, which is being used across the UK alongside another vaccine made by Pfizer.
But an internal letter from NHS England to vaccination venues had just emerged, warning staff of “a significant reduction in weekly supply available from manufacturers beginning in the week commencing March 29, meaning volumes for first doses will be significantly constrained.”
The letter said the UK Vaccines Taskforce “now currently predict this will continue for a four-week period, as a result of reductions in national inbound vaccines supply”.
Replying to journalists, Mr Hancock said: “Vaccine supply is always lumpy, and we regularly send out technical letters to the NHS to explain the ups and downs of supply over the future weeks, and what you’re referring to is a standard one of those letters.”
He did not mention any specific problem with overseas suppliers, and when questioned on BBC Radio 4’s Today Programme the following morning, Housing Secretary Robert Jenrick said: “It’s not that there’s any one factory that’s responsible for this, or any one country.”
Later that day, Matt Hancock told the House of Commons in a statement: “We have a delay in a scheduled arrival from the Serum Institute of India.”
He added that the UK authorities were also retesting a batch of 1.7 million doses already in the country to check its stability, adding to the delays.
Made in India?
Reuters first reported in February that the UK medicines regulator was inspecting Serum Institute facilities in India ahead of a plan to import Indian-made Oxford/AstraZeneca vaccine to Britain.
The government later confirmed that 10 million of the 100 million doses the drug company has agreed to supply would be made in India.
It came as a surprise to many people who had been following the story of vaccine manufacturing, because the understanding was that almost all vaccine for use in the UK would be made at facilities in this country, with a small amount imported from Europe.
In a briefing to journalists on December 7 last year, Ian McCubbin, manufacturing lead for the UK government’s Vaccines Taskforce, said: “The vast, vast, vast majority of what will be produced by AstraZeneca for the UK will be in the UK.”
He said a small number of doses would initially come from facilities in EU countries but added: “The remainder of the supply will be a UK supply chain.”
There was no mention of India then, which raises the question of when and why it was decided to ask the Serum Institute to supply 10 million doses, rather than rely solely on UK manufacturers.
The Reuters report that broke the story suggests that officials from the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) were still carrying out an ongoing inspection of facilities in India as recently as February 15.
The MHRA told FactCheck they had “recently” inspected the Serum Institute’s manufacturing process and “are pleased to confirm that globally recognised quality standards are being met”.
“A certificate of Good Manufacturing Practice has been issued to the Institute,” the MHRA added. We don’t when the regulator signed off on the Indian manufacturers.
Is AstraZeneca hitting its targets?
FactCheck has previously reported how AstraZeneca missed several early forecasts of how much vaccine it would be able to produce for the UK.
Predictions that we would have 30 million doses by September last year, 100 million doses by the first half of this year and 40 million doses by the end of March all fell by the wayside.
The company has consistently committed to delivering 2 million doses a week, but it’s not easy to check whether this benchmark is being hit.
The Department of Health does not divide its vaccination figures into separate brands, so it’s not possible to tell at first glance how much Pfizer and how much AstraZeneca vaccine is being used.
But you can dig those figures out of the “yellow card” data published by the government, which lists reports of possible side effects.
Archived data from the yellow card site suggests we have only managed to administer 2 million doses of AstraZeneca vaccine in two out of the last six weeks we have data for.
The average has therefore been less than 2 million a week, even though the company said in January that it would scale up production “imminently” to deliver 2 million doses a week and were “absolutely on track to do that and, therefore, deliver tens of millions of doses in the first quarter of this year”.
That suggests a target of more than 20 million doses by the end of March.
The latest yellow card data shows that 11.7 million doses of AstraZeneca vaccine had been administered by March 7, similar to the total number of Pfizer doses, although the figures are not very precise.
It’s possible that AstraZeneca has actually delivered more vaccine than these figures suggest, and that batch testing or other limitations of the rollout which are beyond the control of the company have delayed getting it into people’s arms.
But the Health Secretary played down the significance of these kind of delays on Thursday, saying: “Because we get supplies out into the field so fast, and run a highly lean delivery system, changes in future supply schedules impact on the weekly availability of vaccine.”
AstraZeneca has not responded to FactCheck’s requests for information on weekly vaccine supply, and a UK government source told us it would not provide us with the figures “as they are commercially sensitive”.
What’s the big picture?
More than 26 million adults in the UK have now received a first dose of one of the two available vaccines, which means Britain’s vaccination programme is one of the biggest and fastest in the world.
The UK government insists it will still hit the target of offering a vaccine to all over-50s by April 15, and all adults by the end of July.
Moderna, the makers of another vaccine cleared by regulators for use in the UK, said recently that they expect to deliver the first doses to Britain by April.