What full FDA approval of Pfizer’s vaccine means for the course of the pandemic

By granting full regulatory approval for the Pfizer-BioNTech COVID-19 vaccine, scientists say the U.S. Food and Drug Administration has provided a critical tool to help the nation stem a worrisome rise in new infections driven by the Delta variant.

The FDA’s decision, announced on August 23, could lead to a substantial increase in vaccination rates, says Leana Wen, an emergency physician and public health professor at George Washington University. Not only is full approval expected to ease the concerns of the hesitant, but it also paves the way for more vaccine mandates, and it provides doctors more latitude in prescribing booster doses.

“It’s a huge milestone,” Wen says. Acting FDA commissioner Janet Woodcock also described the decision in a statement as one that "puts us one step closer to altering the course of this pandemic in the U.S.”

In December, the FDA made an exception to its typical approval process when it granted emergency use authorization (EUA) to Pfizer’s vaccine based on two months of safety data. At the time, the regulatory agency emphasized that the benefits of having a vaccine during a global pandemic outweighed the potential costs.

The approval process that Pfizer just cleared is the industry standard, requiring six months of data showing that a vaccine or drug is safe and effective. It is the same process that all other drugs go through before they are put on the market.

However, the approval doesn’t apply to all age groups. Pfizer’s vaccine remains under emergency use authorization for adolescents ages 12 through 15 and for immunocompromised individuals who are seeking a third dose.

Persuading the unvaccinated

Public health experts hope the FDA’s decision will convince people who have been wary of COVID-19 vaccines due to safety concerns to finally get a first dose. In May a Kaiser Family Foundation survey showed that 32 percent of unvaccinated people said they would be more likely to get a shot once it had been fully approved.

“For whatever reason there is a great deal of anxiety about the EUA because it happened so quickly,” says C. Buddy Creech, director of the Vanderbilt Vaccine Research Program in Tennessee. “I think this will take a few people off the fence.”

Experts emphasize that there’s no scientific basis for concerns about the emergency use authorization process. The vaccine clinical trials and subsequent review of the safety data were as rigorous as they are for any other drug or vaccine. Wen also points out that these vaccines have since been given to hundreds of millions of people—providing clear evidence that they are safe and effective.

“I think that full approval will also potentially change the framework for how we discuss these vaccines—that they are no different than any of the other vaccines that people routinely take,” she says.

Pfizer can also throw the full weight—and budget—of its marketing machine behind the rollout of its vaccine, which will now be sold under the brand name Comirnaty. In the weeks ahead, people can expect to see a flurry of ads and commercials aimed at persuading people to get a shot, and Wen says she thinks this will help move the needle on vaccination rates.

A rise in vaccine mandates

The FDA’s approval is also likely to trigger a new wave of vaccine mandates in the days and weeks ahead. Although some companies and universities already require their employees and students to get vaccinated, they have faced legal challenges arguing that the vaccines under emergency use authorization are experimental and risky.

“This takes the argument out of play,” Creech says.

Wen agrees. She expects that having the FDA’s full approval will help many companies and schools that have been hesitant to open themselves up to lawsuits to enact vaccine mandates.

Existing mandates, too, are on increasingly solid legal ground. Wen points out that legal challenges have not been very successful under the EUA. In June a federal judge threw out a lawsuit over the Houston Methodist Hospital’s vaccine mandate, saying it didn’t break any federal laws. Earlier this month, the U.S. Supreme Court refused to hear a challenge to Indiana University’s vaccine mandate.

Federal and state government agencies have also begun to enact vaccine mandates. The U.S. Department of Veterans Affairs already requires vaccines among its frontline healthcare workers, and California was the first state to require all teachers and school staff to either get a vaccine or undergo weekly COVID-19 testing.

On August 9, the U.S. Department of Defense announced that it planned to make COVID-19 vaccines mandatory for active-duty service members by mid-September. Now that the FDA has granted full approval to Pfizer’s vaccine, the Pentagon says it will speed up that mandate.

Paving the way for booster doses

FDA approval is also likely to drive an influx of booster doses among the fully vaccinated even sooner than anticipated.

“If you look at the numbers, we have more people who will be clamoring for that third dose than we do people who will be looking to get their first dose,” Creech says.

Under emergency use authorization, doctors are required to strictly follow U.S. regulators’ dosing guidance. Following an August 12 revision to the EUA, some people with compromised immune systems began receiving third doses—and more than a million have reportedly already received unauthorized boosters.

But with a fully approved drug or vaccine, Creech says that doctors have the latitude to use their own clinical judgment in treating their patients. For those who they deem to be at high risk, doctors may begin prescribing third vaccine doses—or a booster dose of the Pfizer vaccine to those who originally got the Johnson & Johnson shot.

On September 20, the Biden administration plans to begin offering boosters to fully vaccinated people eight months after their second dose. The rollout will begin with the elderly and frontline workers. But the FDA’s approval of Pfizer’s vaccine means that not everyone will need to wait eight months after they were fully vaccinated. Wen argues that timeline is arbitrary anyway.

“Nothing magical happens at eight months,” she says, adding that full approval allows physicians to make decisions based on the facts in front of them. For example, she says, a physician could make the call to give a third dose now to an elderly patient with chronic renal disease, emphysema, and heart failure who lives with an unvaccinated family member.

“Physicians have to be able to use their clinical judgment in discussion with their patient,” she says.

Many scientists have argued that there’s no evidence that booster shots are necessary for most Americans. The vaccines continue to be extremely effective in protecting against severe disease and hospitalization, which is what they were made to do. But Creech counters that some of the doses are nearing the end of their shelf life and it’s better to offer third doses than to let them expire, so long as we prioritize people who are more vulnerable to severe disease.

Stemming the worrying rise of COVID-19 cases

Ultimately, public health experts are hoping rising vaccination levels will put a dent in case rates, which are spiking across the country—primarily among the unvaccinated. Although 14 percent of Americans have said in recent surveys that they will never get a vaccine, Creech says any upward tick in vaccination helps.

However, the rise of the more transmissible Delta variant is rapidly changing that calculus. As the newly dominant strain in the U.S., Delta is driving that onslaught of new infections. Studies suggest, however, that Pfizer’s vaccine remains effective against the Delta variant, protecting against severe disease, hospitalization, and death. Public health experts say improving access to the vaccine could go a long way toward saving lives.

“We have been able to prevent an incredible amount of hospitalizations and deaths because of those who are vaccinated,” Creech says.