Moderna COVID-19 vaccine shown effective in 12 to 17 years olds in Phase 2/3 study

Plans are underway to submit the Moderna, Inc. COVID-19 vaccine to regulators in early June to expand its use, following positive results from a Phase 2/3 study that distributed the vaccine among adolescents aged 12 to 17 years old.

The vaccine, known as mRNA-1273, met its primary immunogenicity endpoint in the study. During the course of the TeenCOVE study, no cases of COVID-19 were observed in participants who received two doses of the vaccine, and an efficacy of 93 percent was observed in seronegative participants from 14 days after the initial vaccination dose. The latter focused on milder cases of the disease.

In all, more than 3,700 participants were enrolled. Data from the study will form the basis of another submission to regulators to expand the vaccine’s use.

“We are encouraged that mRNA-1273 was highly effective at preventing COVID-19 in adolescents,” Moderna CEO Stéphane Bancel said. “It is particularly exciting to see that the Moderna COVID-19 vaccine can prevent SARS-CoV-2 infection. We will submit these results to the U.S. FDA and regulators globally in early June and request authorization.”

No significant safety concerns emerged during the trial, which randomized participants 2:1 with two 100 µg doses of either mRNA-1273 or placebo. Four cases of COVID-19 emerged among those given placebo, whereas none appeared in the properly vaccinated group. Accounting for only a single COVID-19 symptom and a positive nasopharyngeal swab or saliva sample, efficacy among the vaccinated was slightly less, at 93 percent.

As far as side effects, most consisted of pain at the injection site, though other effects commonly seen among adults were reported, including headache, fatigue, myalgia, and chills. An independent safety monitoring committee will monitor all participants for 12 months after their second injection.