LONDON – British regulators on Wednesday warned that people with a history of severe allergic reactions should not receive the new Pfizer-BioNTech vaccine as they investigate two side effects that occurred on the first day of the country’s mass vaccination program.
The UK Medicines and Health Products Regulatory Agency is investigating whether the reactions were related to the vaccine. The two people affected were members of the National Health Service staff who had a history of allergies and are both recovering. The authorities did not say what their reactions were.
In the meantime, the regulator has issued a warning to anyone who has had a significant allergic reaction to a vaccine, drug or food. This includes anyone who has been told to take an adrenaline shot or others who have had life-threatening allergic reactions.
“As is often the case with new vaccines, the MHRA has advised, as a preventive measure, that people with a significant history of allergic reactions should not receive this vaccination after two people with a history of significant allergic reactions react. negatively yesterday, ”said Professor Stephen Powis, medical director for the NHS in England, said in a statement. “Both are recovering well. ”
The medical regulatory agency also said vaccinations should not be done in facilities that do not have resuscitation equipment.
Pfizer and BioNTech said they were working with investigators “to better understand each case and its causes.”
Late-stage trials of the vaccine found “no serious safety issues,” the companies said. More than 42,000 people received two doses of the vaccine during these trials.
“In the pivotal phase three clinical trial, this vaccine was generally well tolerated without any serious safety concerns reported by the independent data oversight committee,” the companies said.
Documents released by the two companies showed that people with a history of severe allergic reactions were excluded from the trials, and doctors were asked to look for such reactions in trial participants who were previously not known to have symptoms. severe allergies.
Even in non-emergency situations, health authorities must closely monitor new vaccines and drugs because studies of tens of thousands of people cannot detect a rare risk that would affect 1 in 1 million people.
Dr Peter Openshaw, professor of experimental medicine at Imperial College London, said there was a “very small” chance of an allergic reaction to any vaccine.
The MHRA last week gave emergency clearance for the Pfizer-BioNTech vaccine, making Britain the first country to allow widespread use.
The UK began its mass vaccination program on Tuesday, offering the vaccine to people over 80, nursing home staff and some NHS workers. It is not known how many people have received the jab so far.
As part of its emergency clearance for the vaccine, the MHRA has asked healthcare workers to report any adverse reactions to help regulators gather more information on safety and efficacy.
The agency is closely monitoring the vaccine rollout and “will now investigate these cases in more detail to understand whether the allergic reactions were related to the vaccine or were fortuitous,” he said. “The fact that we are aware of these two allergic reactions so early and that the regulator has acted accordingly to issue precautionary advice shows that this monitoring system is working well. ”
Dr June Raine, head of the medical regulatory agency, briefed a parliamentary committee on the reactions during previously scheduled testimony on the pandemic.
“We know from very large clinical trials that this was not a feature,” she said. “But if we need to strengthen our advice, now that we have had this experience in vulnerable populations, the groups that have been selected as a priority, we immediately get that advice on the ground. ”
Associated Press writers Frank Jordans in Berlin contributed.