Moderna Therapeutics announced positive interim data from the Phase 2/3 KidCOVE study of its COVID-19 vaccine (mRNA-1273) in children 6 months to under 2 years and 2 years to under 6 years of age. This interim analysis showed a strong antibody response in both age groups after a 25 µg two-dose primary series of mRNA-1273, along with a favorable safety profile. However, the vaccine didn’t match the 90% efficacy seen in adults in late-stage trials. In children 6 months to 2 years, efficacy against infection was 43.7% and it was 37.5% in the 2 to under 6 years age group. Moderna blamed the efficacy rate drop on the emergence of Omicron and said these rates are still statistically significant.

Based on these data, Moderna said it will submit a request for authorization of a 25 μg two-dose primary series of mRNA-1273 for children 6 months to under 6 years of age to the U.S FDA, European Medicines Agency (EMA), and other global regulators in the coming weeks. Additionally, Moderna is filing an Emergency Use Authorization submission for use in children ages 6 to 11 years old and is updating the EUA submission to the FDA for mRNA-1273 in adolescents ages 12 to 17 years with additional follow-up data.

KidCOVE is a randomized, observer-blind, placebo-controlled study to evaluate two doses of mRNA-1273 given to healthy children 28 days apart. The study population is divided into three age groups (6 to <12 years, 2 to <6 years, and 6 months to <2 years). In the study, efficacy could be evaluated if enough cases accrued. Overall, the Company enrolled approximately 11,700 pediatric participants in the U.S. and Canada into the trial including approximately 4,200 children ages 2 to under 6 years and approximately 2,500 children ages 6 months to under 2 years. The trial is expected to be complete in June of 2023.

Moderna is preparing to evaluate the potential of a booster dose for all pediatric populations, including those age 6 months to under 6 years, 6 to under 12 years, and adolescents.