The Pfizer Vaccine Is Likely to Be Approved

Here are the key takeaways from the FDA hearing

Dana G Smith
Medium Coronavirus Blog

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Credit: ANGELA WEISS / Getty Images

The U.S. Food and Drug Administration’s (FDA) vaccine advisory committee has officially voted in favor of the Pfizer/BioNTech vaccine for Covid-19. After almost nine hours of presentations and debate, the 22 members in attendance voted 17 to four (with one abstention) that the benefits of the vaccine outweighed its risk.

This does not mean that the vaccine has been approved. The FDA will decide in the coming days about whether to officially grant an emergency use authorization (EUA) for the Pfizer vaccine. However, the FDA is expected to move forward with the recommendation of the committee, which is made up of independent infectious disease experts.

The vote was based on safety and efficacy data Pfizer presented, as well as an independent analysis conducted by the FDA, showing that the vaccine is 95% effective at preventing Covid-19 and that it has minimal side effects. Out of 36,523 participants enrolled in the study, eight people who received the vaccine developed Covid-19, while 162 people in the placebo group fell ill. Notably, no data is available yet about whether the vaccine prevents asymptomatic infections with the novel coronavirus; all that is known so far is that it prevents Covid-19 disease.

In terms of side effects, Pfizer reported that pain, redness, and swelling were common at the vaccine injection site, and nearly 60% of people experienced fatigue and headache afterwards. A smaller percentage also reported chills, muscle and joint pain, diarrhea, and fever in the seven days after receiving the vaccine, particularly following the second dose. Interestingly, side effects were more common in younger adults, presumably because their immune systems are stronger and mount a more robust reaction to the vaccine than older adults.

A major question throughout the clinical trials has been whether various demographic groups would respond differently to the vaccine. Pfizer presented preliminary data meant to allay these concerns, showing that there was no difference in efficacy between older and younger adults, men and women, racial and ethnic groups, and people with and without preexisting conditions like diabetes, cardiovascular disease, and obesity.

The one source of contention during the meeting was whether the authorization should include 16-year-olds and 17-year-olds. Older adolescents were added during the later stages of the clinical trial, and Pfizer provided safety and efficacy data on only 153 people in that age range. Several of the committee members, particularly the pediatricians in the group, recommended that the EUA only apply to people 18 years and up until more data is collected.

Once the vaccine is authorized, Operation Warp Speed has vowed to begin vaccine distribution within 24 hours. Pfizer says 25 million doses will be available to the U.S. by the end of the year, although the vaccine requires two doses given three weeks apart, meaning 12.5 million Americans will have initial access to it. Last week, the U.S. Centers for Disease Control and Prevention’s (CDC) own vaccine advisory committee recommended that health care workers and people living in long-term facilities should be prioritized to receive a vaccine first.

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Dana G Smith
Medium Coronavirus Blog

Health and science writer • PhD in 🧠 • Words in Scientific American, STAT, The Atlantic, The Guardian • Award-winning Covid-19 coverage for Elemental