In a 17-4 vote (with one abstention) the U.S. Food and Drug Administration’s (FDA) vaccine advisory committee recommended that Pfizer/BioNTech’s COVID-19 vaccine should be distributed to the American public.
With that recommendation hand, an FDA team led by the agency’s commissioner Dr. Stephen Hahn will now make a final decision about whether to issue an emergency use authorization (EUA) for the vaccine for anyone 16 years and older. The committee vote is not binding, but the agency is likely follow its advice, especially given the urgent need for a vaccine to stave off a rising tide of new infections. The FDA decision could happen at any time.
“We have been looking forward to presenting our robust data package to the committee of vaccine experts for the U.S. government since we began our efforts to develop a novel COVID-19 vaccine earlier this year,” said Dr. Albert Bourla, Pfizer Chairman and CEO in a statement. “We are pleased with the vote, and if the FDA issues an authorization, stand at the ready to bring this vaccine to people in the U.S. in an effort to help combat this devastating pandemic.”
Bourla has said the company is ready to begin shipping doses within hours of an EUA issuance. The vaccine has already received approval in the UK and health officials began vaccinating people there on Dec. 8; it has also been approved in Canada, where the first shots are expected next week.
During the day-long meeting of the FDA’s Vaccines and Related Biologics Products Advisory Committee, the 22 voting members heard a presentation from Pfizer scientists detailing the 44,000-person study that showed the vaccine was 95% effective in protecting against COVID-19 disease, as well as an analysis from FDA scientists of that data and earlier trials of the shot. Pfizer’s data showed that the vaccine was equally effective across different age groups, among people from different racial and ethnic backgrounds and among people with underlying health conditions—critical data since Black and Latinx populations have been disproportionately affected by the disease, as have those with chronic health conditions. “There were no specific safety concerns identified in the analysis of [these] subgroups,” said Dr. Susan Wollersheim, medical officer in Center for Biologics Evaluation and Research at the FDA, who presented the agency’s analysis.
If the EUA is granted, it would mean the vaccine could be distributed like any other approved shot, with an important caveat. EUAs are granted only under public health emergencies, and so require manufacturers to report follow up data on safety and effectiveness on a shorter time frame than usual. Pfizer and BioNTech will continue the studies they began in six countries (the U.S., Argentina, Brazil, Germany, South Africa and Turkey) and follow participants for two years to collect more information on how long the immunity provided by the vaccines lasts, and whether any serious side effects occur over time. Already, days after the UK began vaccinating some citizens with the Pfizer/BioNTech shot, the health regulatory agency there issued a warning that people with allergies severe enough to require them to carry epinephrine should not get vaccinated after two health care workers with allergies developed severe reactions to the shot.
Pfizer and FDA scientists have received more information on the two cases in the UK that prompted the warning, and said a related one could be included in the EUA for the vaccine in the U.S. Some committee members felt more data were needed specifically on people with allergies to allay people’s concerns over the potential safety of the vaccine for them; any EUA will likely include requirements that rescue medications be available at vaccination locations for anyone who is vaccinated in case they develop anaphylactic shock. “We are aware of the reports of anaphylactic shock and are continuing to monitor the situation closely,” said Wollersheim.
If the vaccine receives the FDA’s EUA, it would be historic for a number of reasons. For one, it would be the first vaccine based on mRNA technology to receive authorization in the country. mRNA is a genetic material that codes for proteins; the Pfizer/BioNTech vaccine is built around the mRNA coding for the COVID-19 virus’s spike protein, which is encased in a fatty lipid particle and injected into the body, where immune cells recognize it as foreign and target the viral material for attack.
Because all that’s required to create an mRNA vaccine is the genetic sequence of the virus, these shots can be developed relatively quickly compared to more traditional methods. The genetic sequence of the COVID-19 virus, called SARs-CoV-2, was released in January, and by May the companies injected the first volunteer in its human trials. That speed could set a new precedent for developing vaccines not just against emerging infectious diseases but also for influenza; Pfizer and BioNTech’s partnership began, in fact, with a program to develop an mRNA-based flu vaccine.
Because the technology is new, however, the vaccine advisory committee members raised a lot of questions about how regulators would monitor its safety, especially among younger people for whom there is less data (Pfizer expanded enrollment to include adolescents after the trial began). One committee member, Dr. Cody Meissner, professor of pediatrics at Tufts University School of Medicine, abstained from voting due to his discomfort with including teens 16 and 17 years old in the EUA. “I do not believe there is sufficient data on 16- to 17-year olds. I would prefer to say [the EUA is for] use in 18 year olds and older,” he said, adding that “16- and 17-year olds do not get very sick, they are seldom hospitalized, and I bet they are a very small number of deaths.”
Pfizer and the FDA responded to the concern by outlining plans to continue studying younger populations (the current ongoing study now includes children as young as 12). They also discussed including in the EUA requirements for continued monitoring of potential side effects among all those who are vaccinated. Those efforts will include a new text-based system for contacting people who are vaccinated, and which those individuals can use to report any potential side effects, along with established systems for doctors and hospitals to report adverse events.
Another concern about the Pfizer/BioNTech vaccine is that it needs to be stored and shipped at -70°C (-94°F), far below normal freezer temperatures. Pfizer is shipping the shots using its own specially designed thermal packaging, which will maintain these ultra-cold temperatures with dry ice for up to 15 days. Each pizza-sized box will contain around 95 vials of frozen vaccine; each vial will need to be thawed and then diluted with 1.8 ml of a provided sterile solution to make five doses of vaccine. Once diluted, a vial can be stored in the refrigerator or at room temperature for up to six hours.
Pfizer says its containers are equipped with GPS readers that will allow them to track every package, as well as with temperature sensors that will provide alerts to the company or recipient of the vaccines if the shots are too warm.
As soon as the FDA makes its decision, the first doses will be shipped to states and distributed to health care workers along with residents of long term care facilities. A recent Centers for Disease Control advisory committee determined that these two groups should receive the shots first based on their risk of exposure to COVID-19 or their vulnerability to getting sick from the disease. CVS and Walgreens have entered into agreements with the U.S. government to administer the vaccines in long term care facilities.