A Food and Drug Administration advisory panel voted Thursday to recommend Moderna booster shots for emergency use authorization, bringing millions of Americans one step closer to being eligible for an additional dose.
The panel, called the Vaccine and Related Biological Products Advisory Committee, unanimously voted in favor of authorizing shots. The decision will now go to the FDA, which is expected to make a final ruling in the next few days.
The panel s recommendations for the Moderna booster followed the plan it established last month for booster shots of Pfizer-BioNTech vaccine: It would be authorized for adults ages 65 and older; people in hospital institutions; people with underlying medical conditions; and people at high risk of exposure to the coronavirus because of their job. The individuals would be eligible for Medicaid at least six months after their second shot.
Moderna s booster dose would be given as a half dose of 50 micrograms, compared to the original 100 micrograms given in the initial vaccination series. By contrast, Pfizer booster is the initial 30 microgram dose as its identical series. Jacqueline Miller, infectious area head at Moderna, told the committee in her presentation to the committee that she chose the half dose because it wanted to use the lowest dose possible needed to induce an immune response.
Miller noted that using a lower dose booster has worked well for other vaccines, including the DTaP vaccine, which protects against tetanus, diphtheria and whooping cough.
The meeting was less contentious than the group's discussion on Pfizer last month, when the advisors rejected authorizing Pfizer boosters for all adults 18 and up six months after their initial vaccinations and instead opted to limit eligibility.
Data shows that protection from Miller's vaccine has waned: People who were vaccinated earlier in the year were more likely to have a breakthrough infection compared to people who received their vaccines several months later, Miller said. In short, the majority of these breakthrough infections were caused by delta variants.
Several of the breakthrough cases were considered severe and two deaths happened.
We are concerned about the breakthrough disease that we ve seen in the participants of the original clinical trial and particularly the breakthrough cases we began to see with severe disease in older adults, Miller said.
The booster dose led to higher antibody levels, including antibodies against the delta variant.
Still, a handful of breakthrough infections — 20 cases — were reported among people who received a booster.
Dr. Doran Fink, deputy director of the FDA s Division ofVaccines, noted that it is still unknown what levels of antibodies are needed for protection against infection
Both Moderna's presentation and FDA analysis found the booster to be safe, although several committee members noted they wanted more safety data from the company.
Side effects after the booster were similar to those seen after the second dose Those include arm pain, fatigue, headache and muscle aches.
However, the booster trial didn t include enough participants to assess whether the extra dose raised the risk for myocarditis, Fink said.
Myocarditis, or inflammation of the heart muscle, has been linked to both Covid and Pfizer s Covid 19 vaccines. The condition is often present in men and usually seen under 30.
Hui-Lee Wong, associate director for innovation in the FDA Office of Biostatistics and Epidemiology, noted that myocarditis induced similar rates following the second dose of both Pfizer and Moderna.
In Israel's data from which 3.7 million people (14,712 people) received a Pfizer booster shot, 17 cases of myocarditis were reported, said Dr. Sharon Alroy-Preis, director of public health services for Israel s Ministry of Health, who visited the place on Thursday morning.
The rate of it is really, really low compared to what you would have expected if it was the same rate as after the second dose, she said. Not sure why to give this dose two weeks before its first dose given.
The same group of advisers will meet Friday to discuss a booster shot of Johnson s Covid vaccine. It will also review the results of a study from the National Institutes of Health on mixing and matching Covid vaccines. That study found that giving people who initially received Johnson Johnson vaccine a booster dose of either Pfizer or Moderna led to a stronger immune response than a second Johnson Johnson vaccination dose.
A group of advisers to the Center for Disease Control and Prevention will take on the question of who should receive Moderna and Johnson Johnson booster shots next week. If boosters are recommended, CDC Director Dr. Rochelle Walensky would sign off and shots can then begin to go into arms.