Moderna Vaccine Reports Robust COVID-19 Antibody Response in Children

Unpublished data from the company's ongoing pediatric trial show children aged 6 to <12 years old have an antibody response greater than that of young adults.

Unpublished, interim data from Moderna’s phase 2/3 pediatric trial showed a lesser dose of the company’s 2-dose COVID-19 vaccine mRNA-1273 is associated with a significant neutralizing antibody response in children aged 6 to <12 years old.

The shared data from the ongoing KidCOVE trial, which includes a cohort of 4753 pediatric participants, will be used in Moderna’s application to the US Food and Drug Administration (FDA) for regulated use of the mRNA vaccine in preventing COVID-19 among the pediatric age group.

The randomized, blinded, placebo-controlled KidCOVE is an expansion assessment of 2-dose 50 mcg mRNA-1273 in health children aged 6 months to <12 years old. Though the trial is continuing to enroll children aged 6 months to <6 years old in North America, Moderna has reached its endpoint for assessment of the cohort aged 6 to <12 years old.

Investigators assessed a comparison of SARS-CoV-2 neutralizing antibody response in vaccinated children versus that observed in young adults included in Moderna’s phase 3 COVE trial, using a geometric mean ratio (GMR). At 1 month following the second dose of 50 mcg mRNA-1273, GMR of response from observed children versus young adults was 1.5 greater (95% CI, 1.3 – 1.8), with a seroresponse rate of 99.3% (difference, 0.6%; 95% CI, -2.8 to 2.8).

The vaccine was generally well tolerated in children aged 6 to <12 years old, with a safety and tolerability profile consistent with that observed in adolescents and adults from the phase 3 trial. Adverse events were generally mild or moderate in severity, and the most commonly reported events included fatigue, headache, fever, and injection site pain.

In a statement accompanying the data, which is yet to be peer reviewed, Stephane Bancel, Moderna chief executive officer, expressed optimism brought on by the newest pediatric COVID-19 vaccination metrics.

“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,” Bancel said. “We look forward to filing with regulators globally and remain committed to doing our part to help end the COVID-19 pandemic with a vaccine for adults and children of all ages.”

Pediatric immunity from COVID-19 continues to be an under-addressed issue in pandemic response; data from the American Association of Pediatrics (AAP) show children comprise more than 16% of all US cases—a rate has been on the rise in past months. For the week ending October 14, children made up 25.5% of the weekly reported COVID-19 cases, despite only comprising 22.2% of the country’s population.

In a recent interview with Contagion, Monica McArthur, MD, PhD, of the University of Maryland School of Medicine, stressed the growing understood need for COVID-19 mitigation and prevention in younger children.

“Part of the concern with rollout for high-risk populations was vaccine scarcity, and I don’t think we’re faced with that as much anymore,” McArthur said. “My hope is that as soon as the vaccine becomes available under EUA for children aged 5-11 years old, it’d be available for all children.”