On Friday, December 11th — two days after the single deadliest day of the Covid-19 pandemic in the U.S. so far — the Food and Drug Administration (FDA) has issued an emergency use authorization (EUA) for Pfizer’s Covid-19 vaccine. This follows an outside advisory panel’s recommendation that the agency take this step — one of the last before distribution of the vaccine can begin. Here’s what you need to know about this milestone, and what happens next.
What is the Pfizer Covid-19 vaccine?
Clinical trials on the Pfizer-BioNTech Covid-19 vaccine began in the United States on May 4th, 2020, when researchers at the University of Maryland School of Medicine vaccinated the first volunteer. Since then, the research has moved with unprecedented speed, while maintaining the usual safety and scientific standards. Both the Pfizer vaccine as well as one from Moderna — which will be evaluated by the same expert panel on December 17th — use messenger (m) RNA, in which a piece of genetic code instructs cells to make portions of the coronavirus spike protein, tricking our bodies into producing the antibodies needed to fight off the virus. So far, the Pfizer vaccine has been approved for use in the United Kingdom and Canada.
A green light from the FDA’s advisory panel
After more than eight hours of reviewing and discussing the data from the Pfizer Covid-19 vaccine, the Vaccines and Related Biological Products Advisory Committee (VRBPAC) gave it their stamp of approval via a 17-4 vote (with one abstention), indicating that the benefits of the vaccine outweigh its risks in people aged 16 and above.
The four votes against the recommendation were at least partially out of concern over the inclusion of 16- and 17-year-olds in the EUA, because the clinical trial data on these younger participants are limited. But that will soon change: Pfizer began testing the vaccine on children as young as 12 at the end of October, though that data wasn’t included in the EUA application.
Additionally, VRBPAC members raised questions about the two allergic reactions among the thousands of vaccine recipients in the United Kingdom, as well as about the safety of the vaccine for pregnant and/or immunocompromised individuals, and those with severe allergies. The meeting also included discussions on whether participants in the clinical trials who received the placebo should have the option of receiving the actual vaccine once it is approved. Addressing concerns regarding what is still unknown about a vaccine is a common part of this process.
What is an Emergency Use Authorization?
As the name suggests, emergency use authorizations are only granted during declared health emergencies. The temporary approval was designed for scenarios like the Covid-19 pandemic, where a vaccine, treatment, device or test is needed as soon as possible to decrease the ongoing massive loss of life. And while there must be strong evidence to suggest that it will have widespread benefits, the extent of safety and efficacy data normally required for FDA approval is not yet available. An EUA is issued when the FDA believes that, on balance, the benefits of releasing the product (in this case, the Pfizer vaccine) outweigh the potential risks that come from having limited data. According to Pfizer executive William Gruber, the pharmaceutical company plans to file for full FDA approval by April 2021.
The next steps
As the FDA prepared their decision regarding the authorization of the vaccine, the CDC’s Advisory Committee on Immunization Practices (ACIP) also met on Friday to discuss whether to recommend the vaccine for widespread use — as well as specifics regarding dosages and intervals between shots. On Saturday, the ACIP approved the vaccine for people 16 and over. Once the CDC officially accepts the ACIP’s decision, and the emergency use of the vaccine is cleared by both the FDA and ACIP, the distribution process begins. The first shipment of the vaccine — containing 2.9 million doses — is scheduled to leave the Pfizer warehouse within 24 hours of the FDA granting an EUA, the New York Times reported.
But deploying the vaccine will take longer than initially anticipated. On December 3rd, Pfizer announced that supply chain obstacles have caused a delay in their worldwide manufacturing timeline. Instead of the 100 million doses they’d hoped for this year, the pharmaceutical company now expects to produce up to 50 million doses of the vaccine by the end of 2020 (25 million going to the United States), followed by up to 1.3 billion doses in 2021. This is in addition to a New York Times report from earlier this week, which indicated that Donald Trump turned down multiple offers from Pfizer this summer to secure up to 500 million doses of the vaccine — a claim Health and Human Services Secretary Alex Azar quickly denied.
In a statement issued late on Thursday night, President-Elect Joe Biden called VRBPAC’s recommendation to the FDA “a bright light in a needlessly dark time.” He then went on to thank the scientists and researchers who developed the vaccine, and looked ahead his plans after taking office. “Vaccines don’t equal vaccinations,” Biden said, adding that the next challenge is to scale up manufacturing and distribution to distribute 100 million shots in his administration’s first 100 days in office.
In order to get the vaccines — as well as the necessary equipment and supply kits — distributed as quickly as possible, FedEx and UPS have “split the country into two,” with each company responsible for deliveries to specific states. If the approval process continues as expected — with the FDA issuing an EUA and the CDC recommending the vaccine for use — the first doses could be administered to health care workers and nursing home residents as soon as early next week. On December 1st, ACIP identified these two groups as being the highest priority in the vaccine rollout, and at this point, still must meet to discuss who will be included in the next phases of the vaccination program.
But the biggest challenge may be the country’s widespread vaccine hesitancy. According to the latest poll numbers from the Pew Research Center released on December 3rd, 60 percent of Americans now say that they would get a Covid vaccine if one became available to them today — a figure that’s down from May (when it was 72 percent), though higher than the September poll, where only 51 percent said they were willing to be vaccinated.
The research continues
The Pfizer vaccine is currently being evaluated based on data from the final phase of the clinical trial — which includes more than 44,000 participants and has a 95 percent efficacy rate — and was recently published in The New England Journal of Medicine. As is standard in vaccine trials, the participants will continue to check in with researchers for two years following their final dose of the vaccine. For now, Pfizer is turning its focus to continuing the research in adolescents between the ages of 12 and 17, and evaluating the safety of the vaccine for pregnant individuals and people with compromised immune systems.
And while the authorization of the Pfizer Covid vaccine is significant, the pandemic is far from over. In fact, it could be several months before the general population has the opportunity to be vaccinated, and once that happens, it will take some time to reach the community-level immunity needed to stop the spread of the novel coronavirus. In the meantime, precautions like wearing face masks, practicing physical distancing and staying home for the holidays are our best defense.