NHS England said in a statement that both of the medical workers who experienced anaphylactoid reactions to the Pfizer vaccine had a “strong past history of allergic reactions,” and that both had recovered after treatment.
“As is common with new vaccines the MHRA (U.K. drug regulator) 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,” NHS national Medical Director for England, Professor Stephen Powis, said in the statement.
The United Kingdom became the first nation in the western world to launch a mass-vaccination program againston Tuesday, to thousands of people at a network of about 70 hospitals across England, Scotland, Wales and Northern Ireland.
There were no other reports of significant adverse reactions to the drug on Tuesday, or “V-Day,” as the government called it. The Pfizer vaccine was approved by Britain’s independent pharmaceutical regulator, the MHRA, for emergency use based on preliminary data from Phase 3 human trials that showed it to be safe and highly effective.
Pfizer, along with U.S. drugmaker Moderna and Britain’s Oxford University working with pharma giant AstraZeneca, are currently waiting for Emergency Use Authorization for their vaccines from the U.S. Food and Drug Administration.
The first 800,000 doses of the Pfizer formula — the only vaccine approved by the U.K. thus far for COVID-19 — are going to people over 80 who are already hospitalized or are scheduled for outpatient procedures, and nursing home staff. NHS workers, particularly those administering the vaccine, are also getting some of the first shots, which are made available at individual inoculation sites once the highest-risk patients get theirs.
The U.K. expects to take delivery of another large batch of Pfizer vaccine doses next week, which will enable the NHS to ramp-up its inoculation program in a bid to treat some 25 million of the most vulnerable people in the first wave.