The CDC's Advisory Committee on Immunization Practices (ACIP) voted unanimously on Thursday to recommend that children ages 6-17 years receive Moderna's COVID-19 vaccine.
With a 15-0 vote, ACIP endorsed a two-dose primary series of the mRNA vaccine for kids ages 6-11 years (50 mcg per dose) and adolescents ages 12-17 (100 mcg per dose). CDC Director Rochelle Walensky, MD, MPH, on Thursday night.
The recommendation was largely expected, and followed FDA's emergency use authorization last week. Until then, only Pfizer/BioNTech's mRNA vaccine had been authorized and recommended for these age groups.
At Thursday's meeting, ACIP members considered safety and efficacy data on Moderna's vaccine, which was primarily studied during periods where the ancestral SARS-CoV-2 and Delta strains were predominant, in teens and the younger kids, respectively. In both groups, the vaccine was effective against severe disease and hospitalization.
"We know that the benefits outweigh the risks for mRNA COVID-19 vaccine in all ages," said Sara Oliver, MD, of the CDC's National Center for Immunization and Respiratory Diseases, during the meeting. "Receipt of this primary series continues to be the safest way to prevent serious COVID-19."
Oliver emphasized that serious outcomes with COVID-19 do not spare kids. The Omicron wave was accompanied by a surge in hospitalizations among children, and she pointed to 189 COVID-related deaths in kids 5-11 years and 443 in kids 12-17 throughout the course of the pandemic.
Several ACIP members raised questions about the intervals between the first and second dose of the Moderna vaccine, as such an approach may reduce the risk of myocarditis associated with the vaccine. Some evidence suggests the Moderna vaccine carries a higher risk of myocarditis or pericarditis than Pfizer's vaccine, though CDC experts cautioned that these findings are not consistent in all U.S. monitoring systems.
Among close to 55 million doses of Pfizer's vaccine administered to individuals ages 5-17 years, the rare adverse event has been observed in at least 635 children, according to the CDC. Risk is typically higher among children ages 12-17, in boys, and after the second dose. Among kids age 5-11, there were no signals detected.
In a presentation on clinical considerations, Elisha Hall, PhD, of the CDC's National Center for Immunization and Respiratory Diseases, said that although the current recommendation is for a 4-week gap between the first and second doses, the CDC will likely be recommending an 8-week interval for adolescent males. (The CDC also recommends shorter dose intervals for children who are immunocompromised.)
Some of the ACIP members expressed confusion about the product labels on Moderna's vaccines in each age group. The product authorized for kids 6-11 will have the same color cap as the vaccine for children ages 6 months to 5 years, but a different color border to distinguish the higher concentration. For the product authorized for kids ages 12-17, it will have the same label as the adult vaccine, as it is the same dose.
"I am ... concerned about vaccine administration errors," said Matthew Daley, MD, chair of ACIP's working group. Others echoed concerns about administration blunders, encouraging more resources for providers and further clarification on labeling from the manufacturer.
Safety and efficacy data for Moderna's vaccine in this younger population came from two ongoing phase II/III clinical trials (study mRNA-1273-P203 for adolescents ages 12-17 and study mRNA-1273-P204 for kids ages 6-11 years). The studies included nearly 8,000 kids in total.
Among participants ages 12-17, vaccine efficacy was 93.3% (95% CI 47.9-99.9) during a time when the ancestral and Alpha strains were predominant. Among the younger group, vaccine efficacy was 76.8% (95% CI -37.3 to 96.6) during a period when Delta was most prevalent.
The committee agreed on the data that COVID-19 vaccines protect children against severe disease. Many children in this age group, however, remain unvaccinated. Approximately 30% of teens and 65% of younger kids have yet to receive a vaccine, according to Oliver.
"We can predict with future COVID-19 surges, the unvaccinated will continue to bear the burden of disease," she said.