There’s mounting pressure on the US Food and Drug Association or FDA requesting the health organization to give formal approval to Pfizer’s COVID-19 vaccine even though medical practitioners, as well as public health experts across the country, can’t pinpoint the exact impact such approval will have on patients as well as health providers.

However, there is the thought that those who are yet to be convinced about the safety of the vaccine will finally give it a shot. The Kaiser Family Foundation conducted a survey back in June where they found out that 3 in 10 unvaccinated adults would be more likely to get the shots if one of the vaccines received an FDA approval.

“People are going to see full approval, and they are going to feel much more confident in taking the vaccine,” said Dr. Robert Murphy, executive director for the Institute of Global Health at Northwestern University’s Feinberg School of Medicine.

Dr. Murphy also stated that the lack of confidence in a vaccine that only got emergency use approval lies in a misunderstanding of what that type of approval means.

“It does not mean it’s experimental. All the experimental work has been done,” he said.

Others agreed that FDA approval could boost some people’s confidence but cautioned that the overall effect is likely to be small.

“I don’t think it’s going to have much change at all,” said the president of the American Academy of Family Physicians. Dr. Ada Stewart, a community clinic doctor in Columbia, South Carolina. “Maybe it will increase confidence.”

There have also been numerous anti-vaccine campaigns without concrete basis across social media platforms like Facebook, which links the vaccine with different conspiracies and that is why Dr. Jesse Goodman who is an infectious disease specialist at Georgetown University Medical Center said that too much misinformation about the vaccine will further drive anti-vaccine rhetorics among the public.

“I think maybe on the perception side, some people who felt this was an extremely or quickly developed product, only developed for emergency use — there might be some people who have more confidence,” Goodman said. “Although I wouldn’t overestimate that.”

Indeed, the same Kaiser Family Foundation survey also found that two-thirds of adults, including many of those who were unvaccinated, believed that all three vaccines available in the U.S. were either already approved or that they were unsure whether they have been or not.

However, full approval could further help companies and cities with vaccine mandates that are becoming more common even though they are still well submerged in different controversies.

“I think a lot of large enterprises, public and private, are waiting for approval to mandate vaccines for students and employees,” said a former FDA associate commissioner, Peter Pitts, president of the Center for Medicine in the Public Interest, a nonprofit advocacy group.

And other more concrete changes come with full FDA approval.

One is the ability to prescribe medication “off label” — a common practice in which doctors prescribe approved drugs for unapproved uses. For example, the diabetes drug metformin is sometimes prescribed for weight loss because one of its side effects is to lower a person’s appetite.

The practice is legal under FDA guidelines, as long as a patient’s doctor judges that “it is medically appropriate for their patient.”

Off-label use is not allowed for drugs granted emergency use authorization, however. Under an emergency authorization, medication can be used only in the specific circumstances outlined in the authorization.

With that, the big question remains whether approval of the Pfizer-BioNTech vaccine will allow doctors to give booster doses to certain full-vaccinated adults as well as children under the age of 12.

Experts say, technically, yes. But should they? That’s more complicated.

“As an approved product, like all medical products, it can be used off label at the discretion of a health care provider and the patient,” said Goodman, who is also a former chief scientist of the FDA and a former director of the agency’s Center for Biologics Evaluation and Research. “But that could have some complicated effects.”

Goodman said little safety data is available yet when it comes to Covid booster shots, so doctors would be taking a risk.

“I think most would follow the recommended approvals from the FDA and what’s been recommended” by the Advisory Committee on Immunization Practices, he said, referring to the Centers for Disease Control and Prevention’s panel of independent advisers that helps set vaccination guidelines. “But clearly not all. There are people who get strong beliefs or if a patient or family member pressures a doctor, they may say OK. It does open the door for some problematic uses.”

The FDA declined to comment on using approved vaccines off-label for boosters. A spokeswoman, Abigail Capobianco, said in a statement: “Americans who have been fully vaccinated do not need a booster shot at this time. FDA, CDC, and NIH are engaged in a science-based, rigorous process to consider whether or when a booster might be necessary.”

Another thing is that doctors might give a vaccine off-label to kids under the age of 12 a group being studied according to Pitts.

“When you use a vaccine off label, you’re playing with fire, because you don’t have the data, and that’s not a good idea,” Pitts said, adding that when medications are used for unapproved uses, some supporting data are typically already available.

“Vaccinating anybody without data to support that decision is a risky proposition, and it shouldn’t happen,” he said.

There are some reports that show that this practice is already happening among full-vaccinated adults who are seeking additional doses. Dr. Eric Topol, a physician-scientist at Scripps Research in California made it known via a tweet that he’s seeing the start of “booster-mania” whereby people go to drugstores and lie about their vaccination statuses.

Besides the health risk, Murphy warns that there could be a legal risk.

Murphy said that because the U.S. government purchased all of Pfizer’s doses, it technically owns them. Patients trying to get third doses or doctors giving boosters by tricking the system could be committing fraud.

“If the vaccine is technically owned by the U.S. government, then that’s a fraud,” he said. “You’re defrauding the government. But if Pfizer sells to private offices, then there’s nothing they can do.”