Moderna’s COVID-19 vaccine appears safe and highly effective in adolescents ages 12 to 17, according to key findings from a small clinical trial the company announced on Tuesday.
The company plans to submit the trial data to the U.S. Food and Drug Administration early next month, in order to obtain approval for expanded use in the age group.
If the FDA grants clearance, Moderna’s vaccine will be the second COVID-19 vaccine available for use in children as young as 12 in the United States. Earlier this month, the FDA cleared the Pfizer-BioNTech vaccine for use in adolescents aged 12 to 15. and up to.)
For the clinical trial, the researchers recruited 3,732 adolescents aged 12 to 17. Two-thirds were randomly assigned to receive the vaccine, while the remaining third received a placebo. The vaccinated group produced immune responses as strong as those seen in vaccinated adults, Moderna reported in a press release Tuesday.
There were no cases of symptomatic COVID-19 among adolescents who received both doses of the Moderna vaccine; there were four cases in the placebo group. The company noted that this was “consistent with 100% vaccine efficacy.” However, the trial was primarily designed to assess immune responses in adolescents, not to establish the rate of effectiveness.
The researchers also looked for very mild infections after the trial participants received their first vaccine. Mild infections were defined as those in adolescents with a positive coronavirus test but only one COVID symptom (rather than two or more, which is often used). Using this definition, the researchers found that a single injection of the vaccine was 93% effective.
The vaccine appeared safe in the young group and produced no serious side effects. Adolescents have reported mild to moderate side effects similar to adults, including pain at the injection site after the first shot and headache, fatigue, myalgia and chills after the second.
In a statement, Moderna CEO Stéphane Bancel said the company was “encouraged” by the results. “We will submit these results to the US FDA and regulators around the world in early June and seek clearance. We remain committed to doing our part to help end the COVID-19 pandemic. “