A pharmacist gives a dose of Pfizer-BioNTech Covid-19 vaccine to a resident of a nursing home in the Bronx district of New York on Dec. 21.
Photographer: Eric Lee / Bloomberg
Photographer: Eric Lee / Bloomberg
Pfizer Inc. said the second dose of his Covid-19 vaccine should be delivered to individuals within the recommended 21-day period, which called into question a UK decision to extend the dosing regimen.
The British decision not to block any of its vaccine supply is aimed at reaching as many high-risk people as possible quickly. Under the government plan, second doses can be administered as much as twelve weeks later, longer than the three-week timing determined by Pfizer’s late study and the four weeks proposed for the shot developed by Moderna Inc.
People should take their shots on the recommended schedule, Pfizer said Thursday, warning: “there is no data proving that protection is maintained after the first dose after 21 days.”
Information about the effectiveness of a single dose has been misinterpreted, says Peter Marks, director of the U.S. Food and Drug Administration’s office that oversees vaccines. Relying on one shot, he said, “is worrying.”
“If people do not really know how protective a vaccine is,” Marks said in an email. ”
Marks’ comments come as the The British Medical Association said on Thursday that the UK decision would require doctors to reschedule appointments for tens of thousands of elderly and vulnerable patients to get their second dose of vaccine. The group called the move “Very unfair.”
Anthony Fauci, the leading American expert on infectious diseases, also took into account the UK’s decision in an interview with NBC’s Today Show on Thursday. The distribution of the two doses is “Under consideration,” he said, though he did not specify by whom.
“I still think, if you do it right, you can do a single dose, discuss doses for the second dose, and still do the job,” Fauci said. But he added: “You can make an argument, and some people are going to stretch the doses and give a single dose across the board, hoping that you will get the second dose in time to give to individuals. give.”
In its statement, Pfizer said that oversight of alternative vaccination schedules is necessary and that authorities should work to ensure that each recipient receives the maximum possible protection.
‘Data from the Phase 3 study showed that, although partial protection against the vaccine appears to start as early as twelve days after the first dose, only two doses of the vaccine are needed to provide maximum protection against the disease, a vaccine efficacy of 95%, ”Pfizer said in a statement.
An FDA document with frequently asked questions about Pfizer and partner Vaccination of BioNTech SE notes that the Agency’s assessment of the safety and efficacy of the vaccine is based on data on patients who received three two – shot shots.
(Add statement by Peter Marks of the FDA in the fourth and fifth paragraphs.)