In recent weeks, the Food and Drug Administration has granted full approval for Pfizer’s COVID-19 vaccine, however, this has not helped to improve vaccination rates in the United States.

“I think it’s going to have a major impact,” said Anthony Fauci, chief medical adviser to the White House. “There are those individuals who understandably, in some respects, don’t want to get vaccinated until they get the full stamp of approval.”

The FDA approval extends only for the Pfizer vaccine for people 16 and older. While not covered by the approval, people ages 12 to 15 have emergency authorization to be vaccinated. Furthermore, no COVID-19 vaccine is authorized for children under the age of 12, however, emergency use is expected to be approved in the following months.

The approval was called “an important milestone that I think will unlock some of the more skeptical minds,” said Pfizer CEO Albert Bourla.

To receive approval for kids such as 12 and under, Pfizer’s vaccine must be effective in preventing illnesses in prepubescent children, therefore requiring extra testing and research.

When speaking about the trial testing for children the agency “has to wait for the company to submit the data from those trials so that we have a good safety dataset, because we certainly want to make sure that we get it right in the children ages 5 through 11 and then even in younger children after that,” said Dr. Peter Marks, the director of the FDA’s Center for Biologics Evaluation and Research.

In addition to Pfizer’s approval, the Moderna vaccine has applied for FDA approval, while the Johnson & Johnson vaccine hopes to do so later in the year.

This approval means that Pfizer has met the “very high standards required of all the approved vaccines we rely on every day,” said Dr. Jesse Goodman of Georgetown University, a former FDA vaccine chief.