Yesterday, the Food and Drug Administration approved Moderna’s COVID-19 vaccine for individuals 18 years of age and older. Upon approval, the Moderna vaccine will be marketed as “Spikevax.” The Emergency Use Authorization (EUA) of Moderna’s COVID-19 vaccine will remain in place for individuals 18 years of age and older.

“The FDA’s approval of Spikevax is a significant step in the fight against the COVID-19 pandemic, marking the second vaccine approved to prevent COVID-19. The public can be assured that Spikevax meets the FDA’s high standards for safety, effectiveness and manufacturing quality required of any vaccine approved for use in the United States,” said Acting FDA Commissioner Janet Woodcock in the FDA’s press release. 

“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.” 

Moderna, like Pfizer, retains Emergency Use Authorization (EUA) 

As was the case for the approval of Pfizer’s Comirnaty vaccine back in August 2021, Moderna’s approved Spikevax vaccine is interchangeable with its emergency authorized counterpart. However, in Pfizer’s case, a federal judge recently rejected the pharmaceutical company’s assertion that their approved Comirnaty vaccine was legally interchangeable with their EUA one.

According to the press release, “Spikevax has the same formulation as the EUA Moderna COVID-19 Vaccine and is administered as a primary series of two doses, one month apart. Spikevax can be used interchangeably with the EUA Moderna COVID-19 Vaccine to provide the COVID-19 vaccination series.”

Spikevax’s efficacy

Moderna’s phase three of its clinical trial began after its vaccine was authorized for emergency use in December 2020, and according to Spikevax’s “Package Insert,” the trial took place over “a period of months.” 

The FDA’s press release states that “The data used for the analyses were accrued before the Omicron variant emerged,” suggesting the trial must have ended prior to Omicron’s arrival in November 2021.

The analyses to determine the effectiveness of Spikevax included 28,451 participants who were at least 18 years of age with no prior infections, 14,287 of whom were vaccine recipients while 14,164 received the placebo. 

As reported by the FDA, only 55 cases of COVID-19 occurred in the vaccine group and 744 COVID-19 cases in the placebo group. These data demonstrated that Spikevax was 93% effective in preventing infection and 98% effective in preventing severe disease. 

Spikevax’s safety

Between the FDA and Moderna, the safety of Spikevax was rigorously evaluated—even using a larger sample size compared to the 28,451 participants when analyzing its effectiveness. According to both the FDA and Spikevax’s package insert, the clinical trial involved 30,346 participants 18 years of age and older, with 15,184 vaccine recipients and 15,162 receiving the placebo.

In their conclusion, the FDA was transparent about the risks of myocarditis and pericarditis associated with Spikevax. Referring to these adverse events, the FDA determined that “the data demonstrate increased risks particularly within seven days following the second dose, with the observed risk highest in males 18 through 24 years of age. Available data from short-term follow-up suggest that most individuals have had resolution of symptoms. However, some individuals required intensive care support. Information is not yet available about potential long-term health outcomes.”

Due to these findings, the FDA stated that it is “requiring the company to conduct post-marketing studies to further assess the risks of myocarditis and pericarditis following vaccination with Spikevax,” as well as the “long-term outcomes among individuals who develop myocarditis following vaccination with Spikevax.” 

Moderna has also ensured that the risks of myocarditis and pericarditis are noted in the “Information for Recipients and Caregivers” insert. 

“The benefits of the vaccine outweigh the risk of myocarditis and pericarditis in individuals 18 years of age and older,” the FDA concluded.

In Spikevax’s package insert, Moderna is also transparent when it comes to the vaccine and pregnancies, stating that the available data on pregnant women who’ve been vaccinated with Spikevax are “insufficient to inform vaccine-associated risks in pregnancy.”

Spikevax’s insert also states, “Data are not available to assess the effects of SPIKEVAX on the breastfed infant or on milk production/excretion. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for SPIKEVAX and any potential adverse effects on the breastfed infant from SPIKEVAX or from the underlying maternal condition.”

However, Moderna appears to be committed to further investigating the matter. Contact information for a “pregnancy exposure registry for SPIKEVAX” is included in the vaccine’s package insert and its “Information for Recipients and Caregivers” insert.

“Encourage individuals who receive SPIKEVAX around the time of conception or while pregnant to enroll in the pregnancy exposure registry,” the package insert reads. “Pregnant individuals can enroll in the pregnancy exposure registry by calling 1-866- MODERNA (1-866-663-3762).”

Additionally, despite it not being an FDA requirement, “[Moderna] has committed to conducting additional post-marketing safety studies, including conducting a pregnancy registry study to evaluate pregnancy and infant outcomes after receipt of Spikevax during pregnancy,” according to the FDA press release.