Interim results from the phase 2/3 KidCOVE study are encouraging and demonstrate the safety and effectiveness of the Moderna (mRNA-1273) Covid-19 vaccine in children 6 to 11 years of age.

The KidCOVE study, designed as a randomized, blinded, placebo-controlled trial, examined the safety, effectiveness and reactogenicity of two 50 µg doses of Moderna (mRNA-1273) vaccine in 4753 healthy children. The 50µg dose is half the dose used for the primary vaccination of adults and the same dose approved as the booster dose for adults.

The two doses were administered at a gap of 28 days. All the study participants were grouped into three, based on the age: 6 to below 12 years, 2 to below 6 years, and 6 months to below 2 years.

Results from 6 to below 12 years age group have been released for now.

In the KidCOVE study, the SARS-Cov-2-neutralizing antibody geometric mean ratio (GMR) comparing the response in children to the response in young adults from the phase III Coronavirus Efficacy (COVE) study was 1.5. The seroresponse rate of 99.3% in 6- to 11-year-old participants was within 0.6% of the rate seen in young adults in the phase III trial of Moderna vaccine. 

Fatigue, headache, fever and injection site were the commonly reported adverse events and were generally mild to moderate in severity.

These results demonstrate the protective effect of the vaccine one month after the second dose. The antibody response was comparable to that seen in adults and teenagers from the COVE phase III study. The vaccine was also well-tolerated indicating a favorable safety profile. The children will be monitored for a year after the second dose of the vaccine.

Moderna will present these findings to the US FDA and the European Medicines Agency (EMA) and seek authorization for the use of its vaccine in children aged 6-11 years.

Currently, the Moderna vaccine (two doses) is approved for use (EUA) in persons aged 18 years and older. Recently, a single booster dose of the vaccine has been approved for administration in individuals aged ≥65 years, persons aged 18-64 years at high risk of severe COVID-19 including those with frequent institutional or occupational exposure to SARS-CoV-2. Children aged ≥12 years can get the Pfizer-BioNTech Covid-19 vaccine; no vaccine has been authorized for children 5-11 years of age in the US. India has so far not yet started vaccination for children, although ZyCoVD (Zydus Cadila) has been approved. Bharat Biotech has conducted trial Covaxin in children between the ages of 2 and 18 and submitted data to the regulatory authority. Similarly, Covishield has also conducted a limited trial on children aged 12-17 years and has submitted the data. A decision is awaited on these two vaccines.

References

1. Moderna announces first vaccine efficacy data in 6- to 11-year-old kids - Medscape - Oct 25, 2021.
2. Moderna announces positive top line data from phase 2/3 study of COVID-19 vaccine in children 6 to 11 years of age, October 25, 2021. https://investors.modernatx.com/news-releases/news-release-details/moderna-announces-positive-top-line-data-phase-23-study-covid-19.