On Monday morning, the Food and Drug Administration (FDA) granted full approval to the first Covid-19 vaccine — a significant milestone in the ongoing fight to end the pandemic. Eight months after issuing Emergency Use Authorization (EUA) to the Pfizer-BioNTech Covid-19 vaccine, followed by millions of shots in arms across the United States and other parts of the world, the FDA gave their final and highest stamp of approval to the two-dose vaccination for people 16 and up.

Though the review process ahead of granting EUA to the Pfizer-BioNTech vaccine — which will now be marketed as Comirnaty (pronounced ko-meer-nah-tee) — was extremely thorough, the one for full FDA approval was even more exhaustive. “We evaluated scientific data and information included in hundreds of thousands of pages, conducted our own analyses of Comirnaty’s safety and effectiveness, and performed a detailed assessment of the manufacturing processes, including inspections of the manufacturing facilities,” Dr. Peter Marks, director of FDA’s Center for Biologics Evaluation and Research, said in a statement


In addition to bolstering the confidence of those who have already received the vaccine, full FDA approval brings with it new rules regarding how and when the vaccine may be used and, in some cases, required. But with Covid vaccines remaining highly politicized, it has yet to be seen whether the approval will have a real impact on the country’s sluggish vaccination rates.

In an interview with NPR’s Mary Louise Kelly a few hours after the FDA’s decision, Dr. Anthony Fauci sounded hopeful about the potential impact of having a Covid vaccine with full FDA approval.

“This is purely an estimate, but I think there are probably about 20 or more percent of people who were not getting vaccinated among the 90 million or so people who are eligible to be vaccinated who have not gotten vaccinated,” Fauci, the director of the National Institute of Allergy and Infectious Diseases and chief medical advisor to the president, said. “I believe that those people will now step forward and get vaccinated — so you’re going to have a group of people who otherwise would not have gotten vaccinated.”

Here’s a look at what will change now that there’s a Covid-19 vaccine with full FDA approval.

More widespread vaccine mandates

One of the most visible and wide-reaching consequences of the Pfizer-BioNTech vaccine receiving full FDA approval will likely be an increase in Covid-19 vaccine mandates. While some state and local governments, private corporations, healthcare systems, universities, and school districts have already implemented vaccine mandates, full FDA approval for a Covid vaccine means more will follow suit. 


“It certainly makes it easier for employers, schools, etc. to mandate vaccines,” says Dr. Howard P. Forman, professor of radiology and public health, and director of the health care management program at the Yale School of Public Health. “While they seemed to have no legal problem doing so, before, it offers a much easier and historically defensible case after full approval.”

Indeed, within minutes of the FDA granting full approval to the Pfizer-BioNTech vaccine, announcements of new vaccine mandates began rolling in. One of the first came from New York City, which will now require all Department of Education employees (from teachers to administration to support staff) to receive at least one dose of vaccine prior to September 27th, noting that weekly Covid testing is not an alternative to vaccination, the New York Times reports.

Unsurprisingly, there have been legal challenges to the vaccine mandates mounting across the country since they were first introduced — and for those involved, today’s FDA approval is a major blow. “The biggest difference [of having full FDA approval of a Covid vaccine] is that this will take away most of the lawsuits against the [vaccine] mandates,” says Dr. Dorit Rubinstein Reiss, a professor at the University of California Hastings College of the Law, where she specializes in vaccine law and policy. “Most of the lawsuits against university and employer mandates highlight the vaccines’ EUA status, and approval removes that argument, and makes those cases very, very hard, because we have a long history of vaccine mandates [in the United States].”

The possibility of off-label use

Along with allowing Pfizer to actively market Comirnaty to the public via TV commercials and other forms of advertising, today’s announcement from the FDA also carries with it the possibility of off-label use of the vaccine. In other words, it gives doctors the ability to prescribe this vaccine for reasons beyond its approved use. Two potential scenarios include giving patients early booster doses, and prescribing the vaccine to children under the age of 12.

Forman says that boosters are the most obvious off-label use of the newly approved Covid-19 vaccine, including situations where physicians prescribe a dose of the Pfizer vaccine prior to the official start of the booster rollout on September 20th, as announced by the White House last week. “In addition, we could easily imagine boosters being offered over a shorter interval — for example, [after] five months, as in Israel, versus the eight months that the U.S. seems inclined to endorse,” he tells Rolling Stone.


The Pfizer vaccine is currently available to children between the ages of 12 and 15 under EUA. This age group — which has been studied in separate clinical trials — was not included in today’s full FDA approval, though is expected to get it once the review of the data from the trials is complete. 

Off-label use in children under the age of 12, however, comes with some concerns. “We have not seen data on the under-12 studies yet, and I would caution anyone to reserve judgment on that group until we actually see data,” Forman explains. “I have no reason to believe it would not be true for younger individuals, but think it prudent to see data.” 

Along the same lines, Reiss says that she thinks “most doctors would hesitate to prescribe the vaccine to a preteen” without the use first receiving approval from the Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices (ACIP). “The ACIP can make recommendations off-label also,” she tells Rolling Stone. “So if we get to the point where there’s really strong need for use in children, and if the FDA hasn’t acted on the EUA yet, it’s hard for me to see [the ACIP] going there, but they can.”

According to Forman, some of the off-label uses could also come with benefits. “In the UK, stretching the interval between first and second doses has seemingly been accompanied by a more robust immune response, ultimately,” he says. “I would presume that the FDA approval would indicate the usual 19 to 23 day interval that was used in the trial, but stretching this to 12 weeks might be an appropriate off-label use.”

The potential impact on vaccination rates

At this point, it’s too early to predict the extent of the impact today’s FDA approval will have on vaccination rates. The most recent Kaiser Family Foundation (KFF) poll, however, does offer some insight. In July, three percent of adults surveyed indicated that they would only get the Covid vaccine if they were required to do so by their employer — a scenario many may face following the expected new wave of vaccine mandates. This figure is down from six percent in June’s poll.

As has been the case since the vaccine rollout began, there is a small number of people with a history of vaccine allergies and/or specific medical conditions that have concerns over whether the benefits of a Covid vaccine would outweigh any potential risks caused by their illnesses. In these scenarios, it’s not necessarily a case of people being opposed to receiving a Covid vaccine, but rather, are approaching the decision with particular caution. However, CDC guidance indicates that Covid vaccines “may be administered to most people with underlying medical conditions,” and recommends that anyone hesitant about getting the vaccine for medical reasons speak with their healthcare provider for advice.


But what about those who remain vaccine hesitant for other reasons? The results of the KFF’s June poll found that 31 percent of unvaccinated adults said that they would be more likely to get a Covid vaccine once one received full FDA approval. (That piece of data was not provided in the KFF’s July poll.) So does this mean that group is out of excuses and will willingly get vaccinated? Reiss isn’t convinced that will happen.

“I’m kind of suspicious that this is really their deciding factor,” Reiss says. “I doubt most of these people know the process.” Specifically, Reiss expects at least some of the people who said that they’d get a Covid vaccine after one has been granted full FDA approval to change their opposition to the claim that the approval process was rushed for political reasons. “I expect that on hesitancy, the effect [of full FDA approval] will be marginal,” she adds. 

Similarly, Forman doesn’t see this milestone as one that will significantly move the needle on vaccination rates. “I would imagine it will cause some immediate bump, but not a huge one,” he says. Forman also stresses the importance of recognizing “that we all have irrational — and maybe even rational — fears about medical interventions,” when considering those who continue to refuse to be vaccinated. 

“When you are deeply enclosed in a misinformation echo chamber that is telling you that this vaccine will make you infertile, impotent, cause permanent damage to your brain, heart, etc., it may be rational to be fearful,” he explains. “So it is important to respect that these people are not crazy, but perhaps overly susceptible to bad information.” 

But at the same time, Forman is optimistic that the perceptions of Covid vaccines among this group could gradually shift. “The anti-vax movement in this country is not new, and it has generally crossed political, demographic, racial, and socioeconomic lines,” he says. “But I do believe that most can be reasoned with — however much time it might take.”