It's emerged two people had allergic reactions after being given the Pfizer BionTech vaccine in Britain yesterday.
Professor Stephen Powis, national medical director for the NHS in England, said: "As is common with new vaccines, the MHRA have advised on a precautionary basis that people with a significant history of allergic reactions do not receive this vaccination after two people with a history of significant allergic reactions responded adversely yesterday.
"Both are recovering well."
It was the first day of the UK's rollout.
The British health regulator's now issued a warning that people with a history of 'significant' allergies shouldn't have the jab for now.
The MHRA's chief executive Dr June Raine says investigations are underway.
"If we need to strengthen our advice, now that we've had this experience, in the vulnerable populations, we get that advice to the field immediately."
