The recommendation includes people over 65 years old, and those older than 18 who are at risk for serious illness or are likely to be exposed at work, such as healthcare workers.
FDA officials aren’t required to follow the panel’s recommendation, but they often do. An advisory committee for the Centers for Disease Control and Prevention (CDC) is scheduled to meet next week to discuss whether to recommend Moderna boosters for this population.
In August, the FDA authorized the third dose of mRNA vaccine for immunocompromised individuals. Last month, regulators authorized a Pfizer booster for people 65 years and older and high-risk groups, but left Moderna and Johnson & Johnson out of the decision because of insufficient data.
Is a Moderna Booster Necessary?
The Moderna vaccine appears to remain highly protective against the most severe COVID-19 outcomes.
According to data presented by Moderna at the panel, the vaccine is more than 98% effective at preventing severe COVID-19 and 93% effective at preventing all illness five months after the second dose.
The Moderna vaccine has held up better against hospitalization over time than the Pfizer vaccine, per a CDC study. Over the course of four months, the effectiveness of the Pfizer vaccine dropped significantly, from 91% to 77%, while Moderna’s effectiveness dropped only slightly, from 93% to 92%.
Instead of arguing that its booster shot would further protect against severe disease and death from COVID-19, Moderna said it would decrease the risk of breakthrough infection and mild-to-moderate illness.
Even mild and breakthrough cases can cause serious outcomes, like long COVID and blood clots, said Peter Marks, MD, PhD, director of the Center for Biologics Evaluation and Research.
Moderna’s data showed that the mean antibody level of participants in its study was 1.8 times higher after they received a half-dose booster.
The adverse side effects experienced by study participants following the booster shot remained generally the same as after the second dose. The most common side effects are injection site pain, headache, fatigue, and muscle pain. Booster recipients reported higher levels of swelling and tenderness than after the original regimen.
Will Boosters Be Approved for the General Population?
The FDA panel discussed, but did not vote on, whether all American adults should be eligible for a booster dose.
Some panelists said that there is not yet enough data to administer boosters to people beyond those determined to be at high risk of severe COVID-19, and that doing so might suggest the primary vaccinations are not protective against serious outcomes.
“I’m uncomfortable with how we’ve sort of tripped down the line for the thought of universal booster dosing, which I just think is wrong,” Paul Offit, MD, a pediatrician and director of the Vaccine Education Center at the Children’s Hospital of Philadelphia, said during the panel meeting.
The focus should remain on inoculating unvaccinated people, rather than administering boosters to the general population, he said.
“The people in the ICU aren’t there because they haven’t gotten a third dose—they’re there because they haven’t gotten any dose,” Offit said.
