Britain is going to face a "significant reduction" in vaccine supplies from March 29 onwards, a letter from National Health Service (NHS) England showed Wednesday.
The letter sent by the NHS to local vaccination sites across the country said volumes for first doses are going to be "significantly constrained".
Disruption could last for four weeks, and the British government's vaccines taskforce has told the health service that this is linked to "reductions in national inbound vaccines supply", according to Sky News.
In response, British Health Secretary Matt Hancock said in a press briefing at Downing Street that vaccines supply is always "lumpy", adding that the NHS letter is a normal, operational note.
"I can assure... there is enough supply... to deliver on the offer of a jab for over-50s by the 15 April," he said.
He said under-40s won't have to wait, because the government is on track to deliver jabs to all adults by the end of July.
Vaccine supplies "sometimes go up and sometimes go down" but the government is sticking by its commitments, he said.
The latest development came hours after the British government announced that more than 25.2 million people have now had their first dose of a coronavirus vaccine.
To bring life back to normal, countries such as Britain, China, Germany, Russia and the United States have been racing against time to roll out coronavirus vaccines.
