Moderna Says COVID-19 Vaccine Triggers Strong Immune Response in Children Aged 6-11 Years

Moderna announced positive interim data from a study of its COVID-19 mRNA vaccine (mRNA-1273) in children aged 6 to 11 years, saying it generated a “robust neutralizing antibody response” and had a “favorable safety profile.”

In an October 25, 2021 press release, Moderna said it plans to submit the data to the US Food and Drug Administration and other global regulators “in the near term,” but did not specify when.

The new findings are from the company’s phase 2/3 randomized, observer-blind, placebo-controlled KidCOVE clinical trial, which aims to assess the safety and effectiveness of two 50-µg doses of mRNA-1273 given to healthy children 28 days apart. Participants were divided into 3 age groups (6 to <12 years, 2 to <6 years, and 6 months to <2 years). The data released Monday are from a cohort of 4753 children in the oldest age group.

Results showed that the SARS-CoV-2-neutralizing antibody geometric ratio comparing the response in children to the response in young adults from the phase 3 COVE study was 1.5 (95% confidence interval [CI]: 1.3-1.8), with a seroresponse rate of 99.3%, representing a difference of 0.6% (95% CI: -2.8%-2.8%) to the phase 3 benchmark. These results demonstrate strong immune response in this cohort 1 month after the second dose and met the co-primary immunogenicity endpoints for participants aged 6 to 11 years, according to the press release.

“We are encouraged by the immunogenicity and safety profile of mRNA-1273 in children aged 6 to under 12 years and are pleased that the study met its primary immunogenicity endpoints,” said Moderna CEO Stéphane Bancel, MSc, MBA, in the release.

mRNA-1273 was generally well tolerated among the participants, and the most common adverse events were fatigue, headache, fever, and injection site pain. Enrollment for children aged 6 to under 12 years is complete, but the phase 2/3 study continues to enroll children in the youngest group, aged 6 months to <6 years.

The KidCOVE study continues to be monitored by an independent safety monitoring committee and safety data are still accruing. All participants will be followed for 1 year after their second dose to assess long-term protection and safety, according to the release. Moderna plans to submit data from the KidCOVE study to a peer-reviewed publication.