The US Food and Drug Administration gave its full approval to the Pfizer-BioNTech COVID-19 vaccine on Monday, making it the first COVID-19 vaccine to be licensed by the US government.
The approval is a further endorsement of the mRNA technology that Pfizer, BioNTech, and their competitor Moderna have used to rapidly develop highly effective vaccines against SARS-CoV-2, the coronavirus behind the often-deadly infection. The FDA’s action has also opened the floodgates to vaccination mandates by corporations and governments.
Within hours of the announcement, Chevron instituted a vaccine mandate for some workers. Also on the heels of the approval, the Pentagon issued a vaccine mandate for service members, and New York City mayor Bill de Blasio issued a mandate for all public school employees to be vaccinated, with no exceptions. In advance of the Pfizer approval, many biotech and drug companies had put in place corporate vaccine requirements.
The Pfizer-BioNTech vaccine will be sold as Comirnaty and is approved for people ages 16 and older.
The FDA approval is the culmination of an unprecedented whirlwind of vaccine development. Pfizer and BioNTech, which had originally partnered to develop a flu vaccine, turned BioNTech’s mRNA technology toward COVID-19 in March 2020. With structural and biological knowledge of similar coronaviruses, as well as large-scale funding, the earliest stages of vaccine development went quickly.
Within about 8 months, the companies released Phase 3 data suggesting their vaccine was more than 90% effective at preventing disease. In December 2020, the FDA issued an emergency use authorization (EUA) for the vaccine, and by the beginning of 2021 the first Americans were getting vaccinated against COVID-19.
Sina Bavari, a former Army vaccine and drug researcher, says clinical trials went quickly in part because it is easy to recruit volunteers in the middle of a pandemic. And Tony Moody, an immunologist developing mRNA vaccines at Duke University, says it was fairly easy to see efficacy results quickly because infection rates in the US were so high.
While mRNA may be the vaccine world’s darling, it’s not a sure-fire technology, says Bavari, who is now chief scientific officer at Edge BioInnovation Consulting and Management. It’s not going to prevent every infectious disease, and for others, he says, it won’t work alone.
“Is it going to solve a lot of problems? The answer is yes,” he says. “Is it going to solve all the problems? The answer is no. There will be some areas where mRNA vaccines will not help at all.”
Traditional vaccines often involve a time-intensive step of growing viruses that carry the immune system target. mRNA vaccines cut out much of that process. Instead, using lipid nanoparticles as delivery agents, they put genetic information directly into cells and rely on the body’s machinery to quickly convert it into a piece of protein that the immune system will react to. In particular, the Pfizer vaccine teaches the body’s immune system to recognize the spike protein on SARS-CoV-2.
Adding to the rapid development and deployment of the Pfizer-BioNTech vaccine were manufacturing agreements with other large pharma companies, including Novartis and Sanofi, and with ingredient suppliers such as Croda, Merck KGaA, and Evonik Industries.
As part of the full approval, Bavari says, the FDA looks not only at safety and efficacy data, but also at manufacturing and supply processes. He expects that other COVID-19 vaccines, including Moderna’s mRNA vaccine and Johnson & Johnson’s more traditional vaccine, will be fully approved as well. Moderna is still completing data submissions; J&J has said it plans to file for full approval by the end of the year.
“I do have to tip my hat to Pfizer for pushing this forward quickly. They were committed to getting this done,” Bavari says of the approval. He stresses that work needs to continue on developing antivirals for diseases like COVID-19.
Pfizer’s EUA is still in effect for use in children ages 12–15 and to allow people who are immunocompromised to receive a booster shot. Clinical trials are underway for use in children younger than 12. An approval for use in older teens and adults does not mean that doctors will start giving the vaccine to younger children, Moody says, noting that the American Academy of Pediatrics has urged its members not to use the vaccine off-license.
Moody says he expects licensure for children ages 12–15 to come quickly. As for the youngest children, who seem to be getting sicker with the Delta variant, the trials are fully enrolled, he says, and data is being gathered.
Nearly 38 million people in the US have tested positive for SARS-CoV-2. About 629,000 people have died. The Delta variant of SARS-CoV-2, a virus with slight mutations in the spike protein, has fueled the latest wave of the pandemic in the US, but further testing has suggested that the Pfizer vaccine is immediately protective against the variant.