51˶

Moderna's COVID Vax for Youngest Kids Hits Important Milestones

— Company plans to submit to FDA for emergency use authorization

MedpageToday
A photo of a vial of the Moderna covid vaccine laying on a box of more vials.

Moderna's two-dose COVID-19 vaccine regimen for the youngest children was safe and met its primary immunogenicity endpoint, the

An interim analysis of the phase II/III KidCOVE study found that two 25 μg doses of Moderna's vaccine in two age groups -- 6 months to under 2 years; and 2 to 5 years -- had comparable immunogenicity to two 100 μg doses of vaccine in adults ages 18 to 25, and met non-inferiority criteria.

Moderna also announced that the vaccine met its secondary endpoint of vaccine efficacy during the Omicron wave, "using the phase III COVE study COVID-19 definition," which consisted of one clinical symptom and a positive test. Efficacy for children age 6 months to under 2 years was 43.7% and it was 37.5% among kids ages 2 to 5.

The manufacturer noted that "the majority of cases were mild," with no severe disease in either age group, and added that based on the immunogenicity results, "this also predicts protection from COVID-19 and severe COVID-19 disease."

Safety was also consistent with other age groups, with the majority of adverse events mild or moderate. About 17% of kids ages 2 to 5 years and 15% of kids ages 6 months to under 2 years had fever (versus 24% in the age 6 to 11 group, who received two 50 μg doses). Only 0.2% of children in each group reported a high fever, and there were no deaths, instances of myocarditis or any new safety concerns reported.

"Given the need for a vaccine against COVID-19 in infants and young children we are working with the U.S. FDA and regulators globally to submit these data as soon as possible," said Moderna CEO Stéphane Bancel in a statement.

The road to a safe and effective vaccine for the youngest kids has been a rocky one, to say the least. Pfizer's two-dose regimen for this younger age group did not meet immunobridging criteria for its 2-to-4-year group. FDA's Vaccines and Related Biological Products Advisory Committee hastily canceled a planned meeting on emergency use authorization (EUA) for this vaccine in February, and Pfizer is in the process of collecting data about a third dose of their vaccine.

Moderna's KidCOVE study was comprised of 11,700 children in three age groups: ages 6 months to under 2 years (n=2,500), ages 2 to 5 years (n=4,200), and ages 6 to 11.

Given these results, the manufacturer announced it is submitting an application for an EUA among kids ages 6 to 11, and has "updated" its EUA application for adolescents ages 12 to 17, though no further details were given as to what that entails.

  • author['full_name']

    Molly Walker is deputy managing editor and covers infectious diseases for 51˶. She is a 2020 J2 Achievement Award winner for her COVID-19 coverage.