Late Monday, Moderna received the FDA’s second full approval for a COVID-19 vaccine, which the company will market as Spikevax™—and which, as with the first fully approved vaccine, Pfizer and BioNTech’s COMIRNATY®, is based on messenger RNA (mRNA).

Spikevax was approved under Priority Review for the prevention of COVID-19 disease in individuals 18 years of age and older—the indication for which the FDA granted Moderna’s vaccine an Emergency Use Approval (EUA) in December 2020.

“This is a momentous milestone in Moderna’s history as it is our first product to achieve licensure in the United States,” Moderna CEO Stéphane Bancel said in a statement.

However, COMIRNATY was approved last year for the prevention of COVID-19 in individuals 16 years of age and older. In October, the FDA authorized emergency use of the Pfizer/BioNTech COVID-19 vaccine in children ages 5–11.

Also, the FDA required Moderna to conduct postmarketing studies to further assess the risks of myocarditis and pericarditis following vaccination with Spikevax.

The agency acted after data from an ongoing Phase III trial showed increased risks, particularly within seven days following the second dose—and especially in males 18 through 24 years of age.

According to the FDA, available data from short-term follow-up suggested that most individuals have their symptoms resolved—though some required intensive care. No data is yet available about potential long-term health outcomes. The postmarketing studies will include an evaluation of long-term outcomes among individuals who develop myocarditis following vaccination with Spikevax.

The FDA said it evaluated post-authorization safety surveillance data pertaining to myocarditis and pericarditis following vaccination with the Moderna COVID-19 vaccine.

That review was part of the agency’s analysis of follow-up safety and effectiveness data from the ongoing Phase III trial that supported the EUA for the vaccine, as well as data gathered following emergency authorization, upon which the FDA said it based its full approval for Spikevax.

The updated analyses from the randomized, placebo-controlled, blinded clinical trial included 14,287 vaccine recipients and 14,164 placebo recipients 18 years of age and older who showed no evidence of SARS-CoV-2 infection before receiving the first dose.

The data was collected before the Omicron variant emerged, the FDA acknowledged.

Targeting Omicron

Last week, Moderna said it dosed its first patient in a Phase II trial assessing an Omicron-specific booster candidate, mRNA-1273.529—a day after Pfizer and BioNTech disclosed the launch of a study evaluating their own Omicron vaccine in healthy adults ages 18–55.

Data cited by the FDA showed Spikevax to be 93% effective in preventing COVID-19, with 55 cases of COVID-19 occurring in the vaccine group and 744 COVID-19 cases in the placebo group. The vaccine was also 98% effective in preventing severe disease.

The FDA also analyzed safety data from the trial of approximately 15,184 vaccine recipients and 15,162 placebo recipients 18 years of age and older. More than half of the participants were followed for safety outcomes for at least four months after the second dose. Approximately 7,500 participants originally assigned to receive Spikevax in the blinded phase of the clinical trial completed safety follow-up for at least six months after the second dose, according to the agency.

The most commonly reported side effects by clinical trial participants were pain, redness and swelling at the injection site, fatigue, headache, muscle or joint pain, chills, nausea/vomiting, swollen lymph nodes under the arm, and fever.

The United States joins more than 70 countries—including Canada, Japan, the European Union, the U.K., and Israel—whose regulators have approved the vaccine.

According to Moderna, 807 million doses of Moderna’s COVID-19 vaccine were shipped globally in 2021—of which approximately 25% were shipped to low- and middle-income countries.

In the United States, according to the Centers for Disease Control and Prevention (CDC), 204,294,985 doses of Moderna’s COVID-19 vaccine have been administered, second only to COMIRNATY (316,390,082 doses). A total of 74,593,062 Americans have been fully dosed with Moderna’s vaccine, compared with 120,498,736 dosed with the Pfizer/BioNTech vaccine.

“While hundreds of millions of doses of Moderna COVID-19 vaccine have been administered to individuals under emergency use authorization, we understand that for some individuals, FDA approval of this vaccine may instill additional confidence in making the decision to get vaccinated,” acting FDA commissioner Janet Woodcock, MD, said in a statement.