Authorization for Moderna's (MRNA) COVID-19 vaccine for ages 12-17 was put on hold Friday in light of concerns over a rare side effect known as myocarditis, or a heart inflammation.
The U.S. Food and Drug Administration decision gives Pfizer's (PFE), which has a similar technology, an advantage in the market. In advisory panel discussions prior to Pfizer's authorization for adolescents, the myocarditis risks were raised, but ultimately the panel decided the benefits outweigh the risks. As a result, Pfizer's vaccine remains on the market for the same age group.
Recent actions by some European countries to avoid Moderna's dose for adolescents has given the FDA pause, according to reports.
National Institutes of Health Director Dr. Francis Collins told Yahoo Finance Friday the decision is really more about timing.
"Pfizer's vaccine was approved for kids 12 and up several months ago, now we have a little more concern and experience with the myocarditis, pericarditis ... I think the FDA is just being careful here," he said.
"I don't know that that should cause anyone any alarm," Collins added, noting that the side effect is reversible in a short period of time.
Dr. Taison Bell, ICU director at UVA Health, said that even though Moderna's is similar to that of Pfizer's, it is a different vaccine with a different efficacy profile.
"This adds to the confusion and the hesitancy, I hear that. But when it comes to vaccinating children, you want to make sure the safety profile is solid," he said.
In addition, Bell noted that the side effect has mostly been seen in men ages 18-24, and that the risk of myocarditis is higher if you contract COVID-19 compared to as a result of the vaccine.
Dr. Leana Wen, former health commissioner of Baltimore and an emergency physician, said that the more urgent issue is getting a vaccine authorized for younger school-aged children.
"The dose for Moderna is more than twice than for Pfizer. Also, there is more than enough Pfizer vaccine to go around for 12+, so there is no pressing emergency with this authorization for Moderna," Wen said.
At this point, Pfizer has already proliferated the market, according to bioethicist Dr. Arthur Caplan, of NYU Langone Health.
"Even if [Moderna] got approval, Pfizer has penetrated that market heavily. The 5-and-up market is still competitive by comparison," Caplan said.
He noted that the real potential for Moderna is overseas, where the market is still highly competitive and undersupplied.
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