The Food and Drug Administration has officially approved the Pfizer (PFE) COVID-19 vaccine, marking the first full approval of a coronavirus vaccine since the pandemic hit the world.

The vaccine is approved for the prevention of COVID-19 in individuals 16 and older and continues to be available for emergency authorization use for those ages 12 through 15 and as a third booster dose for immunocompromised people, the FDA said in a statement.

The Pfizer COVID vaccine was authorized for emergency use in December 2020 for people 16 and older. It was expanded for administration for those aged 12 to 15 in May 2021.

Over 204 million Pfizer shots have been administered in the U.S. to date, according to data from the Centers for Disease Control and Prevention, as reported by CNBC. The FDA said the same dosage regime applies to the approval of the Pfizer COVID vaccine – two doses taken three weeks apart.

The FDA also said that its decision was based on longer duration of follow-up in a larger clinical trial population of approximately 20,000 vaccine and 20,000 placebo recipients ages 16 and older who did not have evidence of the COVID-19 virus within weeks of receiving the second dose of the shot. Safety of the vaccine or “comirnaty” was evaluated in about 22,000 people who received the vaccine and 22,000 people who received a placebo 16 years of age and older.

Results showed the Pfizer COVID vaccine was 91% effective in preventing the virus, the FDA said.

About 12,000 of the recipients were followed for at least six months during the clinical trials of the Pfizer vaccine, with more than half followed for at least four months.

Side effects most commonly reported in the clinical trials from the Pfizer vaccine were pain, redness and swelling at the injection site, fatigue, headache, muscle or joint pain, chills, and fever.

The FDA said the vaccine from Pfizer “is effective in preventing COVID-19 and potentially serious outcomes including hospitalizations and death.”

“The FDA’s approval of this vaccine is a milestone as we continue to battle the COVID-19 pandemic,” Acting FDA Commissioner Janet Woodcock, said in a statement.

“While this and other vaccines have met the FDA’s rigorous, scientific standards for emergency use authorization, as the first FDA-approved COVID-19 vaccine, the public can be very confident that this vaccine meets the high standards for safety, effectiveness, and manufacturing quality the FDA requires of an approved product.

“While millions of people have already safely received COVID-19 vaccines, we recognize that for some, the FDA approval of a vaccine may now instill additional confidence to get vaccinated. Today’s milestone puts us one step closer to altering the course of this pandemic in the U.S.,” she added.

Pfizer said that it plans to request full approval for the booster dose of its COVID vaccine, which the Biden Administration has said it will offer to all eligible Americans beginning the week of Sept. 20. The booster shot will be scheduled eight months after their second dose of the COVID vaccine.

According to the CDC, over 170.8 million Americans have been fully vaccinated against COVID-19, accounting for 51.5% of the U.S. population.

As of Monday at 10:36 a.m. ET, shares of Pfizer were trading at $50.54, up $3.75, or 1.82%.

The United States says it will ship half a billion dozes of the Pfizer vaccine to poor countries starting late this month
The United States says it will ship half a billion dozes of the Pfizer vaccine to poor countries starting late this month AFP / JUSTIN TALLIS