Shot has been tested for kids aged 6 months to 5 years, a group not yet eligible for vaccination in the U.S.
Moderna Inc. has asked U.S. health regulators to authorize the use of its Covid-19 vaccine in children ages 6 months to 5 years old.
The company said Thursday that it had submitted the request after a study showed the shot safely induced immune responses in the young age group.
If the regulators agree, one of the last remaining age groups still not eligible for Covid-19 vaccination in the U.S.—children under 5 years—could begin to receive the shots by summer.
The Food and Drug Administration is expected to convene a public meeting of a panel of outside vaccine advisers within weeks to consider Moderna’s request. An FDA official said at a recent congressional hearing the agency would move quickly once it had a completed application, and would release a schedule for advisory panel meetings within the next week.
If the panel votes to recommend the shot, the FDA could authorize its use soon after, though the agency may seek additional data before making a decision. The FDA has delayed authorizing Moderna’s vaccine — mRNA-1273, or Spikevax—for adolescents to assess whether the shots heighten the risk of aninflammatory heart condition.
Some parents of young children have been clamoring for an authorized vaccine.
The other leading Covid-19 vaccine from Pfizer Inc. and BioNTech SE is authorized for anyone 5 years and older, while Moderna’s has only been cleared for adults 18 and older in the U.S.
“Every day that these kids go without vaccination is another opportunity to get severe disease, to get hospitalized, to get long Covid, so I think there is a need to make this available to children,” Moderna Chief Medical OfficerPaul Burtonsaid in an interview.
To support its application for authorization in adolescents, Moderna said it has provided the FDA additional safety and efficacy data in the age group. Moderna also has started the process of seeking authorization of use of its vaccine in children ages 6 to 11.
Covid-19 cases in children tend to be milder than for adults, but there have been severe cases resulting in hospitalizations and deaths, especially during the Omicron wave during the winter.
Efforts to widen the Covid-19 vaccination campaign to include children under 5 years have hit setbacks in recent months, frustrating some parents who want their young kids vaccinated.
On April 24, a group of parents and doctors named Protect Their Future filed a citizen petition with the FDA urging the agency to immediately review any application for use of a vaccine in children under 5 years.
Kailey Soller said she has been cautious about where she takes her 18-month-old daughter because the toddler is unvaccinated.
“As long as the safety profile looks good for the vaccine, I would vaccinate her,” Ms. Soller, of Chanhassen, Minn., said in an interview. “Once she is vaccinated, we will resume life much more normally. We would feel more comfortable bringing her to a Target, going on vacation.”
The FDA in February delayed a decision on the use of the Pfizer-BioNTech vaccine in children under 5 years after the companies got mixed results in clinical testing.
The delay came after two doses of the Pfizer-BioNTech vaccine didn’t produce a strong immune response in 2- to 4-year-olds, but did so in children under 2 years. The companies are waiting for additional results to see whether providing a third dose improves the immune response.
A Kaiser Family Foundation poll in February found that 21% of parents with children under 5 years plan to get them vaccinated right away. But many parents have no intention of vaccinating their young children, with the same poll finding that 35% of those surveyed said they won’t vaccinate their kids.
Some parents have expressed concern about the safety of the vaccine. The vaccines from Moderna and Pfizer have been associated with an increased risk of heart-inflammation conditions including myocarditis, especially in males under the age of 30, U.S. health authorities say.
The risk of severe Covid-19 is much lower in children than in older adults, but there is still a level of risk that infectious-disease specialists say warrants vaccination.
Some studies have found that the risk of myocarditis after vaccination is lower than the risk of developing myocarditis after Covid-19 infection.
Covid-related hospitalization rates for children in the U.S. rose sharply during the winter surge of Covid-19 cases caused by the Omicron variant, according to the Centers for Disease Control and Prevention. In January, weekly Covid-19 hospitalization rates of children under 5 peaked at about 14.5 per 100,000 children, which was about five times the peak rate during the Delta variant surge, the CDC said.
“Children of any age can become ill with Covid, with those under a year of age and those with underlying conditions being at the greatest risk for severe disease and complications,” said Dr. Tina Tan, professor of pediatrics at Northwestern University Feinberg School of Medicine.
About 28% of children ages 5 to 11 and 59% of adolescents 12 to 17 have received the full primary vaccination series of two doses,according to the CDC. Overall, 70% of the eligible U.S. population has been fully vaccinated.
Moderna is seeking authorization of a dosage of its vaccine in young children that is one-fourth the amount used for adults. Moderna found in a study that two doses of the vaccine safely induced immune responses in children that were comparable to immune responses seen in young adults.
The study found the shot was 43.7% effective against symptomatic Covid-19 infections in children ages 6 months to 2 years, and 37.5% effective in those ages 2 to 5.
Moderna said Thursday that those efficacy figures included cases diagnosed with at-home Covid tests during the Omicron surge. When the analysis is limited only to cases confirmed positive by a central laboratory test, the vaccine was 51% effective in children 6 months to 2 years, and 37% in the older group, the company said.
The company reported these results in a press release. The data haven’t been published in a peer-review journal.
The efficacy rates in children are lower than the 94% efficacy Moderna’s vaccine demonstrated against symptomatic disease in a large study of adults in 2020. But that study was conducted before the more-transmissible Omicron variant, and Moderna said the efficacy in adults against symptomatic disease caused by Omicron is comparable to the rates seen in the pediatric study.
The company said many of the cases took place during the Omicron variant wave in the winter. Covid-19 vaccines generally had lower efficacy against symptomatic infections caused by the highly contagious Omicron variant, though they continued to reduce risk of hospitalization and death, particularly among people who got a booster shot.
Moderna said the majority of cases of symptomatic Covid-19 in the study of young children were mild. There were no severe Covid-19 cases—including hospitalizations and deaths—in any children in the study. As a result, Moderna wasn’t able to assess the efficacy of the vaccine in young children against severe cases including hospitalizations.
Most side effects, like injection-site pain and fever, were mild or moderate, Moderna said. The company observed no new safety concerns, and there were no deaths, myocarditis or cases of an inflammatory syndrome in children reported in the study, Moderna said.