A pharmacist administers a dose of the Pfizer-BioNTech Covid-19 vaccine to a resident of a nursing home in New York’s Bronx neighborhood on Dec. 21.
Photographer: Eric Lee / Bloomberg
Photographer: Eric Lee / Bloomberg
Pfizer Inc. he said the second dose of his Covid-19 vaccine should be delivered to people within the recommended 21-day period, calling into question the UK’s decision to separate the dosing regimen.
The UK’s decision not to withhold any of its vaccine supplies aims to reach as many high-risk people as possible quickly. According to the government plan, second doses could be given up to 12 weeks later, longer than the three-week time determined to be optimal for the final Pfizer studies and the four weeks suggested for the shot developed by Moderna Inc.
Pfizer said Thursday that people should make the shots according to the recommended schedule, warning “that there is no data to show that protection after the first dose is maintained after 21 days.”
Information about the effectiveness surrounding a single dose has been misinterpreted, said Peter Marks, director of the U.S. Food and Drug Administration’s office that oversees vaccines. Based on a shot, he said, “it’s worrisome.”
“If people don’t really know the protection of a vaccine,” Marks said in an email, “there is a potential for harm, as they can assume they are fully protected when they are not and alter their behavior to assume unnecessary risks. ”
Marks’ comments appear as 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 for the move “Seriously unfair.”
Anthony Fauci, the top American infectious disease expert, also took into account the UK’s decision in an interview on Thursday on NBC’s Today Show. Extending the two doses is “Under consideration,” he said, though he did not specify by whom.
“I still think that, if done correctly, you can do a single dose, set aside doses for the second dose, and still get the job done,” Fauci said. But he added: “You can argue, and there are those who do, to extend the doses and administer a single one in the hope that you will get the second dose in time to give it to people.”
In its statement, Pfizer said there is a need to monitor any alternative vaccination program and that authorities should work to ensure that each recipient has the maximum protection possible.
“Phase 3 study data showed that although partial protection against the vaccine appears to begin as early as 12 days of the first dose, two doses of the vaccine are required to provide maximum protection against the disease. , a 95% vaccine effectiveness, “Pfizer said in a statement.
An FDA document of frequently asked questions about Pfizer and its partner The BioNTech SE vaccine notes that the agency’s assessment of vaccine safety and efficacy was based on data on patients who received two shots three weeks apart.
(Add a statement from the FDA’s Peter Marks in the fourth and fifth paragraphs.)