Tuesday's recommendation by a government advisory panel was for a second Covid-19 vaccine to be used in school-age children and adolescents.
Moderna's vaccine was unanimously approved by the Food and Drug Administration's independent experts. If the FDA accepts, the vaccine would be the second choice for these children and join Pfizer's vaccine.
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Wednesday's FDA Expert Panel will be meeting again to discuss tot-sized shots by Moderna and Pfizer with the youngest children, those below 5.
Moderna's Covid vaccine is available to adults in the U.S., and other countries. More than three dozen countries also offer it to children. The Centers for Disease Control and Prevention will decide next whether to recommend Moderna's vaccine for teenagers and younger children if the FDA approves it.
The Massachusetts company has applied for clearance to administer two doses and plans to offer a booster later. Tuesday's vote only approved two doses -- one for adults 12-17 years old and one for children 6-11 years of age.
"The data support that the benefits outweigh any risks for both these doses in both age groups," Dr. Melinda Wharton of the CDC, a member on the panel, stated.
Moderna's teen vaccination was held by the FDA for several months as it examined a rare side effect called heart inflammation. This is a common side effect in teens, but it can also occur with the Pfizer vaccine. Moderna was subject to extra scrutiny due to the fact that its shots are much more powerful.
FDA scientists concluded that there had been no heart inflammation reported in Moderna's child studies. Experts believe that the studies had too few participants to allow for rare side effects like this.
Dr. Mark Sawyer from the University of California San Diego's medical school said, "That clearly needs be watched closely going forward as us expand the use of vaccine."
FDA officials stated that there were no other side effects reported, focusing on headaches, fatigue, and sore arms.
FDA analysis found that Moderna is effective in preventing symptoms of Covid disease in teenagers and younger children. The levels of virus-fighting antibody were comparable to those in young adults.
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According to FDA analysis, vaccine effectiveness was estimated at 93 per cent for teens and 77 per cent for younger children. The FDA analysis shows that the vaccines were tested against older versions of coronavirus, which are still very contagious. The estimates are also based only on a small number of Covid cases.
Moderna officials stated that a booster shot was also added to the studies. Data is expected in the next month. Children who have been vaccinated with Pfizer shots as well as adults are advised to get booster shots.
It is not clear how much Moderna will need shots. Pfizer's vaccine uses the same technology and teens were eligible one year ago. Only 60% of them have received two doses. According to the CDC, shots for younger children began in November. Only 29 percent of them have been fully vaccinated.
A spokesperson for the CDC stated that if the FDA approves Moderna shots for schoolchildren and teens, the agency will not review the vaccine until late this month.