Positive interim data from the phase 2/3 study evaluating the Moderna COVID-19 vaccine, mRNA-1273, in children 6 months to less than 6 years of age showed a robust neutralizing antibody response.

The randomized, observer-blind, placebo-controlled KidCOVE study (ClinicalTrials.gov Identifier: NCT04796896) is currently evaluating the immunogenicity, safety, and tolerability of the mRNA-1273 vaccine in healthy children. The study population includes 3 cohorts: children 6 months to less than 2 years old; children 2 to less than 6 years old; and children 6 to less than 12 years old. In children 6 months to less than 6 years of age, participants received either two 25mcg doses of mRNA-1273 or placebo, separated by 28 days.

Interim results showed that the vaccine in participants 6 months to less than 6 years of age met the primary endpoint with robust neutralizing antibody titers similar to the 100mcg two-dose primary series in adults 18 to 25 years of age. The SARS-CoV-2 neutralizing antibody geometric mean ratio (GMR) comparing the response in children 6 months to less than 2 years to the response in young adults from the phase 3 COVE study (ClinicalTrials.gov Identifier: NCT04470427) was 1.3 (95% Cl, 1.1-1.5) and 1.0 (95% Cl, 0.9-1.2) for the 2 to under 6 years age group.

Additionally, the trial met the secondary endpoint achieving a statistically significant vaccine efficacy when the Omicron SARS-CoV-2 variant predominated in the US. The vaccine efficacy was 43.7% in children 6 months to less than 2 years of age and 37.5% in children 2 to less than 6 years of age.

The safety profile in both cohorts was consistent with that observed in children 6 to less than 12 years, in adolescents 12 to 17 years, and in adults. The majority of adverse events were mild or moderate and were more frequently reported after the second dose. There were no deaths, myocarditis, pericarditis, or multisystem inflammatory syndrome in children reported.

The Company will submit a request for authorization to the Food and Drug Administration (FDA) in the coming weeks for a 25mcg two-dose primary series of mRNA-1273 for children 6 months to under 6 years of age. 

To assess continued protection and safety, all participants will be monitored for 12 months after the second dose. Study data will also be submitted to a peer-reviewed publication.

Reference

Moderna announces its COVID-19 vaccine phase 2/3 study in children 6 months to under 6 years has successfully met its primary endpoint. News release. Moderna, Inc. Accessed March 25, 2022. https://investors.modernatx.com/news/news-details/2022/Moderna-Announces-its-COVID-19-Vaccine-Phase-23-Study-in-Children-6-Months-to-Under-6-Years-Has-Successfully-Met-Its-Primary-Endpoint/default.aspx