On December 11, the U.S. Food and Drug Administration (FDA) authorized the Pfizer-BioNTech two-dose coronavirus vaccine for emergency use, according to a report from The New York Times, which cited three anonymous sources with knowledge of the decision. Officials say that the vaccine could start rolling out to critical workers and some of the most vulnerable people in the country within 24 hours, according to CNBC, and there is a deal between the Trump administration’s Operation Warp Speed and Pfizer to deliver 100 million free doses to the public by March 2021.
The authorization comes after an FDA advisory panel voted to approve the vaccine for emergency use in people 16 and older on December 10. In November the results of a phase-three trial that included around 44,000 participants led researchers to suggest the vaccine prevented symptomatic coronavirus infections in 95% of people, as SELF previously reported. Reports from the FDA in advance of the advisory panel vote indicated that the vaccine seemed to be 52% effective against symptomatic infection after the first dose, then around 95% effective against symptomatic infection after the second dose, the Times reported. And so far the vaccine appears to work well on this front in adults regardless of weight, race, or age. Questions still remain regarding how well the vaccine prevents asymptomatic infections, along with if the vaccine creates actual immunity to the virus (instead of only preventing symptomatic/asymptomatic infection). If it does create immunity to the virus, therefore making it harder for vaccinated people to contract the disease, enough people getting the vaccine could lead to herd immunity. Herd immunity happens when a significant enough number of people in a community are protected from a pathogen, so the disease in question can’t spread in that community.?
The Pfizer-BioNTech vaccine uses mRNA (messenger RNA) technology. This mRNA carries DNA codes the body uses to create proteins, as SELF previously reported. According to the Centers for Disease Control and Prevention (CDC), mRNA vaccines teach our cells to make a certain protein or portion of a protein that kicks off an immune response, creating antibodies to help us ward off an infection (or a certain level of infection, like one that’s symptomatic) if we ever encounter the real pathogen. The Pfizer-BioNTech vaccine is the first mRNA vaccine approved for use in the United States, but scientists have been studying mRNA vaccines for years and used much of that previous research to develop coronavirus mRNA vaccines at record speed. (In addition to the Pfizer-BioNTech vaccine, Moderna’s potential COVID-19 vaccine relies on mRNA technology.) Canada, the U.K., Saudi Arabia, Mexico, and Bahrain have also approved the Pfizer-BioNTech vaccine for most adults, according to the Times.
Researchers did not report any serious adverse side effects related to the vaccine, but more than half of the participants in the biggest trial experienced fatigue and headaches, and others reported fevers, body aches, and other coldlike symptoms, especially after the second dose. “Taking a day off after the second dose is a good thing to anticipate,” Akiko Iwasaki, Ph.D., an immunologist at Yale University, told the Times.
Although potential causation isn’t yet clear, after the Pfizer-BioNTech vaccine rollout began in the U.K., there was one report of a possible allergic reaction in someone who received the vaccine and two reports of anaphylaxis, according to Reuters. (Anaphylaxis is a severe allergic reaction that can cause throat swelling, among other symptoms.) While officials investigate if there is a connection between the vaccine and these reactions, U.K. officials have recommended that people with a history of severe allergic reactions to vaccines or medicine forgo vaccination until they can confirm whether the vaccine was the cause. In the U.S., officials will be monitoring for any reports of adverse reaction after vaccine rollout.