LONDON — People who have a background marked by “critical” allergic reactions ought not get the Covid vaccine created by Pfizer and BioNTech, the U.K. drug controller said Wednesday.

The U.K’s Medicines and Healthcare products Regulatory Agency refreshed its direction to British health service trusts on who ought to get the vaccine after two individuals from Britain’s National Health Service experienced allergic reactions to the shot. Both are recuperating great, as indicated by the national medical director for the NHS.

“Any individual with a background marked by a critical allergic response to a vaccine, medication or food, (for example, past history of anaphylactoid response or the individuals who have been encouraged to convey an adrenaline autoinjector) ought not get the Pfizer BioNtech vaccine,” the regulatory agency said.

Stephen Powis, national medical director for the NHS, said such an insurance “is basic with new vaccines.”

The U.K. was the main nation to support and control the Pfizer-BioNTech vaccine. On Tuesday, it started a gigantic vaccination drive beginning in medical clinics, with health and care home laborers and those over age 80 preferred choice to be immunized.

Dr. June Raine, top of the MHRA, told a U.K. government select committee on Wednesday that the controller would keep up “ongoing carefulness” of the vaccine since it is being conveyed.

“Indeed, even last night we were seeing two case reports of allergic reactions,” she said.