LANCASTER, Pa. (WHTM) — In the midst of a coronavirus surge initiated by the delta variant, Pfizer’s COVID-19 vaccine received full FDA approval on Monday. The process for a vaccine to receive full approval from the Food and Drug Administration is similar to the process for receiving an emergency use authorization, but one main difference is timing.

Two months of data on a vaccine are required for a vaccine to receive an emergency use authorization, while six months of data are needed for full approval, Penn Medicine Lancaster General Health chief of infectious diseases Dr. Joseph Kontra explained.

The Pfizer vaccine, along with the other COVID-19 shots, underwent three phases of study before it received its emergency use authorization last December.

The first and second phases of study investigated the kind of immune response the vaccines triggered and any harmful effects of the shots. The third phase of study looked into the efficacy of the vaccines by administering real and placebo doses to study participants.

The review for full FDA approval looked at a larger sample of vaccine and placebo recipients over a longer period of time than the emergency approval review included, Kontra said.

The full FDA approval for the Pfizer vaccine means the process for getting vaccinated will be easier, Kontra said. It also could potentially mean that patients will have to pay for the vaccines in the future — something they didn’t have to do while the vaccine was under emergency authorization, Kontra noted.

The Pfizer vaccine, which will be marketed as Comirnaty, has received full approval for use in individuals ages 16 and older. For those 12-15 years old, the vaccine is still under emergency use authorization. The booster shots that U.S. officials are now considering would also receive emergency use authorization.

Moderna is currently seeking full FDA approval for its COVID-19 vaccines, as well. It applied for full approval in May about a month after Pfizer, so its approval is expected in the next few weeks, Kontra said. Johnson & Johnson is several months behind Pfizer and Moderna.

Health officials hope that Pfizer’s full approval will encourage those experiencing vaccine hesitancy to go out and get the shot, removing the concern of the vaccine being in an “experimental” phase.