Moderna announced positive interim data from the Phase 2/3 KidCove study of the Moderna COVID-19 vaccine (mRNA-1273) in children aged 6 months to under 2 years old, and aged 2 years old to under 6 years old.
The company said that the interim analysis showed a robust neutralizing antibody response in both age groups after a 25 µg two-dose primary series of mRNA-1273 along with a favorable safety profile.
Based on the data, Moderna will submit a request for authorization of a 25 μg two-dose primary series of mRNA-1273 for children aged 6 months old to under 6 years old to the Food and Drug Administration, European Medicines Agency and other global regulators in the coming weeks.
"We believe these latest results from the KidCove study are good news for parents of children under 6 years of age. We now have clinical data on the performance of our vaccine from infants six months of age through older adults," Stéphane Bancel, CEO of Moderna, said.
Bancel also made note of the need for a vaccine against COVID-19 in infants and young children, by stating that Moderna is working with the FDA and regulators globally to submit these data as soon as possible.
"Additionally, after consultation with the U.S. FDA we have initiated a submission for emergency use authorization of our COVID-19 vaccine in children ages 6 to 11 years old and are updating our submission to the FDA for emergency use authorization of mRNA-1273 in adolescents ages 12 to 17 years with additional follow-up data. We remain committed to helping to end the COVID-19 pandemic with a vaccine for children of all ages," Bancel said.
With approximately 6,700 participants aged 6 months old to under 6 years old enrolled into this age cohort, Moderna shared that in both age groups, the tolerability profile was generally consistent with that observed in children aged 6 years old to under 12 years old, in adolescents aged 12 to 17 years old and in adults.
The majority of adverse events were mild or moderate and were more frequently reported after dose two. Rates of fever greater than 38°C among vaccine recipients were consistent with other commonly used and recommended pediatric vaccines and were 17.0% and 14.6% in the aged 6 months old to under 2 years old and the two to under 6 years old groups, compared to 23.9% in the six to under aged 12 years old group, which received a 50 µg two-dose primary series. Fever greater than 40°C was seen in only a few children (0.2% in each age group). No study pause rules were met, and no new safety concerns were identified in either age group. No deaths, no myocarditis or pericarditis, and no multisystem inflammatory syndrome in children (MIS-C) were reported, the company said.
In both age groups, two doses of 25 µg provided similar immunogenicity to the 100 µg two-dose primary series in adults aged 18 to 25 years old, meeting the non-inferiority criteria and immunobridging, and indicating that the benefit of mRNA-1273 conferred to adults aged 18 to 25 years old are also conferred to children and infants as young as age 6 months old.
SARS-Cov-2-neutralizing antibody geometric mean ratio comparing the response in children 6 months to under 2 years to the response in young adults from the Phase 3 Cove study was 1.3 (95% Cl: 1.1, 1.5) and was 1.0 (95% Cl: 0.9, 1.2) for the aged 2 to under 6 years old age group. This also predicts protection from COVID-19 and severe COVID-19 disease down to age 6 months old, Moderna said.
The Omicron SARS-CoV-2 variant predominated in the United States during the KidCove study in these younger age groups. The secondary endpoint of vaccine efficacy confirms statistically significant, but lower efficacy against COVID-19 infection as expected during the Omicron wave and is consistent with adult observational data. Using the Phase 3 Cove study COVID-19 definition, vaccine efficacy in children aged 6 months old to 2 years old was 43.7% and vaccine efficacy was 37.5% in the age 2 years old to under 6 years old age group. In this case, statistically significant is defined as a lower bound on the 95% confidence interval which is greater than 0. The majority of cases were mild, and no severe COVID-19 disease was observed in either age group. The absence of any severe disease, hospitalization or death in the study precludes the assessment of vaccine efficacy against these endpoints, the company reported.
Similar to adults, Moderna is preparing to evaluate the potential of a booster dose for all pediatric populations, including those aged 6 months old to under 6 years old, aged 6 years old to under 12 years old, and adolescents. The company is evaluating booster doses of mRNA-1273 and its bivalent booster candidate (mRNA-1273.214), which includes Omicron variant booster and mRNA-1273.
Safety data continue to accrue, and the study continues to be monitored by an independent safety monitoring committee. All participants will be monitored for 12 months after their second injection to assess long-term protection and safety. These data are subject to change based on ongoing data collection. The company said that it plans to submit these data to a peer-reviewed publication.