The injections could begin in a few days, depending on how quickly the Food and Drug Administration approves, as expected, the expert committee’s recommendation.
In a vote of 17-4 and one abstention, government advisers concluded that the vaccine from Pfizer and its German partner BioNTech appears safe and effective for emergency use in adults and adolescents over 16 years of age.
That support came despite questions about allergic reactions in two people who received the vaccine earlier this week, when Britain became the first country to start dispensing the Pfizer-BioNTech injection.
Despite all the remaining unknowns, in an emergency, “the question is whether you know enough,” said panel member Dr. Paul Offit of the Children’s Hospital of Philadelphia, who concluded that the potential potential benefits of the injection outweigh your risks.
Independent review by nongovernmental experts in vaccine development, infectious diseases, and medical statistics was deemed critical to increasing Americans’ confidence in the safety of the vaccine, which developed at breakneck speed less than a year after the virus identification.
The decision was made as COVID-19 cases spiked to ever higher levels in the US, with deaths reaching a one-day all-time high of more than 3,100 on Wednesday.
Pfizer has said it will have about 25 million doses of the two-shot vaccine for the United States by the end of December.
But initial supplies will be limited and reserved primarily for healthcare workers and nursing home residents, with other vulnerable groups in line until vaccines are widely available on demand, something that likely won’t happen until spring.
Experts estimate that at least 70 percent of the US population will need to be vaccinated to achieve herd immunity, the point at which the virus can be controlled.
That means it could be several months before things start to get back to normal and Americans can take off their masks.
Next week, the FDA will review a second vaccine, from Moderna and the National Institutes of Health, that appears as protective as the Pfizer-BioNTech injection.
A third candidate, from Johnson & Johnson, who would require just one dose, is working his way down the pipeline.
Behind that is a candidate from AstraZeneca and the University of Oxford.
All eyes are now on the scientists on the FDA staff who will make the final decision on whether to green-light the use of the Pfizer-BioNTech vaccine.
Regulators, not just in Britain but in Canada, have already approved it for use in their countries, and President Donald Trump and White House officials have complained for weeks about the pace of the FDA’s careful review. .
The FDA’s director of vaccines, Dr. Peter Marks, said before the expert meeting that the decision would be made in “days or a week.”
“The Americans want us to do a scientific review, but I think they also want us to make sure we don’t waste time on paperwork rather than follow through with the decision,” FDA Commissioner Stephen Hahn said before the meeting.
A positive vote for the vaccine was virtually assured after FDA scientists released an enthusiastic review of the vaccine earlier in the week.
Agency staff said data from Pfizer’s ongoing study of 44,000 people showed strong protection across different age groups, races and health conditions without major and unexpected safety concerns.
The Pfizer-BioNTech injection remains experimental because that end-stage study is not complete.
As a result, the expert panel wrestled with a list of questions that have yet to be answered.
For example, while the vaccine is more than 90 percent effective in blocking COVID-19 symptoms, FDA advisers emphasized that it is still unclear whether it can stop the silent and asymptomatic spread that accounts for up to half of cases. .
“Even though the individual efficacy of this vaccine is very, very, very high, at this time you really don’t have any evidence” that it will decrease transmission, said Dr. Patrick Moore of the University of Pittsburgh.
He urged Pfizer to take additional steps to answer that question.
And advisers worry that Pfizer will miss an opportunity to answer critical questions as it begins offering the real vaccine to study participants who had received sham vaccines.
The company proposed gradually moving those patients to the vaccine group, with priority based on age, health conditions and other factors.
Under that plan, the 70-year-old participants would cross before the healthy 30-year-olds.
Pfizer has yet to show if the vaccine works in children under 16 and pregnant women.
On the safety front, as widespread vaccinations begin, government health authorities will closely monitor the first recipients, as studies in tens of thousands of people fail to detect rare risks affecting 1 in a million.
Above the meeting were British allergic reactions and a warning from authorities that people with a history of severe reactions should not get vaccinated for now.
Pfizer representatives said they have seen no signs of allergic reactions in their trial.
But some of the FDA’s advisers fear that the British warning will deter millions of Americans with allergies who could benefit from the COVID-19 vaccine from trying it, and they urged additional studies to try to solve the problem.
“This problem is not going to go away until we have better data,” said Dr. Offit.