The United States is the fourth country to recommend a COVID-19 vaccine after an advisory committee voted for emergency use of the Pfizer/BioNTech vaccine Thursday evening.
The U.S. joins the U.K., Bahrain and Canada that have all recently approved the mRNA vaccine — called BNT162b2 — which has shown 95% efficacy in preventing COVID-19.
The FDA is expected to accept its advisory committee’s recommendation within days, meaning vaccine doses could be distributed within days after that.
The committee’s recommendation “based on the totality of scientific evidence available” also allows the Centers for Disease Control and Prevention committee to offer its official recommendation — a decision expected Sunday afternoon following a two-day meeting of the Advisory Committee on Immunization Practices.
Thursday’s vote of 17 to 4 with one abstention reflected a concern among some of the medical, legal and scientific experts on the FDA’s Vaccines and Related Biological Products Advisory Committee that the “emergency use authorization” shouldn’t include 16- to 17-year-olds, as the data was very “thin” for that age group.
Dr. H. Cody Meissner, a professor of pediatrics at Tufts University School of Medicine, who abstained from voting, said he was comfortable with the vaccine’s safety profile for the general public, but “uncomfortable with the question as it’s written. I do not believe we have sufficient data for 16- and 17-year-olds.”
Dr. Paul Offit, director of the Vaccine Education Center and an attending physician in the Division of Infectious Diseases at Children’s Hospital of Philadelphia, said that while 16- and 17-year-olds have much lower rates of infection, he’s still seen some younger teens in his hospital with cardiac anomalies due to COVID-19.
“If you can prevent this disease safely and effectively, we have clear evidence of benefit,” he said. “All we have on the other side is theoretical risk.”
Pfizer’s report
Pfizer presented a lengthy report of its phase 2/3 clinical data, noting that in order to apply for emergency use authorization it had to demonstrate that the vaccine is highly effective and can prevent COVID-19 in the majority of vaccinated people, that the vaccine is safe, as shown in a very large safety study, and that they can consistently manufacture the vaccine to the highest standards, explained Kathrin Jansen, senior vice president and head of vaccine research and development at Pfizer.
“It is estimated that 55,000 deaths could occur over the next few months,” Jansen said. “A vaccine with high efficacy can save many lives; however, a pandemic vaccine must be introduced before the peak of cases, which is the key under EUA.”
Pfizer/BioNTech’s phase 2/3 study included more than 43,000 people, with two-month follow-up data available for 37,586 people and daily electronic journal recordings noting any vaccination response for roughly 8,000 participants.
A graph presented by Pfizer Thursday, and included in a lengthy document presented earlier to the FDA, showed COVID-19 cases among the placebo group compared to the vaccinated group — a stark visual indicator of the vaccine’s efficacy.
The most common reactions were redness, swelling and pain at the injection site, as well as fever, chills and headache that were slightly more pronounced following the second dose, explained William Gruber, senior vice president of Pfizer vaccine clinical research and development.
In addition to concerns about 16- and 17-year-olds, the committee also expressed concerns about pregnant women, for whom there is no data yet.
The other major concern expressed by the committee was about the anaphylactic response experienced by two people in the U.K., which began vaccinating people earlier this week.
In response, the FDA has requested that Pfizer and BioNTech update their pharmacovigilance report to study such allergic responses.
The FDA’s work
The FDA has been in contact with the Medicines and Healthcare products Regulatory Agency, the U.K.’s independent scientific advisory body, said Dr. Marion Gruber, director of the office of vaccines research and review at the FDA.
The FDA has also been working with Pfizer to ensure the vaccine fact-sheets mention the vaccine shouldn’t be given to anyone with a history of severe allergic reactions and that any medical intervention be available immediately for anyone who gets a vaccine.
Offit said he supported moving forward with the emergency approval, but encouraged additional vaccine studies of people with histories of severe egg or peanut allergies “to prove that this is not going to be a problem for them,” he said. There are tens of millions of people who carry epi pens, he said, who may self-select out of getting a vaccine if they don’t feel it’s safe for them.
“It shouldn’t stop us moving forward,” he said. “I’m just saying when it rolls out there, this is going to be an issue and we need to have data.”
Pfizer also indicated that they will be conducting three different follow-up studies for 30 months — checking on 20,000 health care workers, U.S. military and their families as well a study using the Veteran’s Health administration electronic medical record database, according to Dr. Susan Wollersheim, a medical officer in the Center for Biologics Evaluation and Research who presented the FDA’s independent review of the vaccine data.
Prior to the group’s vote, they heard from members of the public, including Evan Fein, a Pfizer study participant who said he believes he got the vaccine in July because he got a fever, chills and mild pain at the injection site, but was called repeatedly by test-site doctors to ask if he was OK.
“I was,” he said. “Nothing felt rushed, I never felt like a guinea pig.” Even in the long-term, it’s been more than five months from his first shot and he is “happy to report” there are no long-term side effects and he encouraged the group to grant the emergency use.
Emergency use authorization is different than full licensure, as it allows the FDA to quickly approve medicines or vaccines for use during public health emergencies, yet still requires they meet crucial safety and efficacy standards.
The FDA and Pfizer also need to work out whether those in the clinical trials who received placebos should be given a vaccine immediately — or if they should continue on as placebos to allow for longer-term data gathering.