Around 5.7million to 6.7million doses of vaccine for the UK have been delayed due to two separate problems, the government announced today.
The Health Secretary updated the House of Commons after the NHS warned of a “significant reduction” in supply from March 29.
After downplaying the issues last night, Mr Hancock gave further details on the cause of the delay, telling MPs they were caused by two separate issues.
The first is a four-week delay to doses from the Serum Institute in India, which had been ordered from the UK. Overnight reporting suggested 5million doses in this order were delayed, but a source today suggested the figure was 4million.
Mr Hancock then revealed there was a second issue with 1.7million separate doses, which needed to be re-tested.
However, he insisted that while parts of the roll-out will be later than some hoped, he was still on track to meet the target of giving a first dose to all over-50s by April 15 and all adults by July 31.
Mr Hancock told MPs: “In the last week we’ve had a batch of 1.7milion doses delayed because of the need to re-test its stability.
“Events like this are to be expected in a manufacturing endeavour and this shows the rigour of our safety checks.”
Mr Hancock did not say whether the extra 1.7million doses were from Pfizer or AstraZeneca or from the UK or abroad.
The two problems combined led the NHS to warn of a major setback in vaccine supply last night in a letter to providers.
Most under-50s in England must wait until at least the start of May, as priority in April will be given to over-50s and second doses.
Unfilled booking slots for later than March 29 will be withdrawn and under-50s won’t be able to book an appointment.
The revelations have dashed wild claims over the weekend that all over-40s could have got a first dose by Easter.
Yet Matt Hancock has desperately tried to play down the scale of the problem, saying his target of offering a first dose to all over-50s by April 15 and all adults by July 31 will still be met.
The Mirror understands there will be almost no first doses offered to healthy under-50s throughout the month of April.
Instead, the second half of April – after (and if) the over-50s target is hit – will be used almost entirely to give second doses.
But Mr Hancock insisted: “There will be no weeks in April with no first doses.
“There will be no cancelled appointments as a result of supply issues – second doses will go ahead as planned.”
Earlier the Serum Institute of India suggested the Indian government was responsible for its delay – risking a diplomatic row ahead of a forthcoming visit by Boris Johnson.
SII chief executive Adar Poonawalla told The Telegraph: “It is solely dependent on India and it has nothing to do with the SII.
“It is to do with the Indian government allowing more doses to the UK.”
This breaking news story is being updated.