LONDON, Dec. 9 (Sky News) - UK regulators have issued a warning that people who have a history of "significant" allergic reactions should not currently receive the Pfizer/BioNTech vaccine.

Two NHS staff members who had the jab yesterday experienced allergic reactions, and are understood to be recovering.

The UK became the first country in the world to approve the Pfizer vaccine last week, and yesterday began vaccinating care home and hospital patients and NHS staff, among others.

Follow live updates as Whitty and Vallance face questions on UK's response to pandemic

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."

The NHS in England said all trusts involved with the vaccination programme have been informed.

The Medicines and Healthcare products Regulatory Agency (MHRA) has given precautionary advice to NHS trusts that anyone who has a history of "significant" allergic reactions to medicines, food or vaccines should not receive the vaccine.

From Wednesday, all patients scheduled to receive the Pfizer vaccine will be asked if they have a history of allergic reactions.

Dr June Raine, the head of the MHRA, told a joint select committee hearing that "real-time vigilance" would continue even now the vaccine had been deployed.

"Even last evening we were looking at two case reports of allergic reactions.

"We know from the extensive clinical trials that this was not a feature, but if we need to strengthen our advice now that we have had this experience in vulnerable populations, the groups selected as a priority, we get that advice out immediately."