British regulators warned Wednesday that people who have a history of serious allergic reactions shouldn’t receive the new Pfizer-BioNTech vaccine as they investigate two adverse reactions that occurred on the first day of the country’s mass vaccination program.
The U.K.’s Medical and Healthcare Products Regulatory Agency is looking into whether the reactions were linked to the vaccine. The two people affected were staff members with the National Health Service who had a history of allergies, and both are recovering. Authorities have not specified what their reactions were.
In the meantime, the regulator has issued the warning for anyone who has had a significant allergic reaction to a vaccine, medicine or food. That includes anyone who has been told to carry an adrenaline shot or others who have had potentially fatal allergic reactions.
“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,” 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 carried out in facilities that don’t 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 concerns,” the companies said. More than 42,000 people have received two doses of the shot during those trials.
“In the pivotal phase three clinical trial, this vaccine was generally well tolerated with no serious safety concerns reported by the independent Data Monitoring Committee,” the companies said.
Documents published by the two companies showed that people with a history of severe allergic reactions were excluded from the trials, and doctors were advised to look out for such reactions in trial participants who weren’t previously known to have severe allergies.
Even in non-emergency situations, health authorities must closely monitor new vaccines and medications because studies in tens of thousands of people can’t detect a rare risk that would affect 1 in 1 million.
Dr. Peter Openshaw, a professor of experimental medicine at Imperial College London, said there is a “very small” chance of an allergic reaction to any vaccine.
The MHRA last week gave emergency authorization to the Pfizer-BioNTech vaccine, making Britain the first country to allow its widespread use.
Photo credit: AP Photo/Frank Augstein, Pool
News source: The Associated Press