Moderna says COVID-19 vaccine safe, 100% effective in children 12-17

May 25 (UPI) -- Moderna said Tuesday its COVID-19 vaccine is safe and effective in children between the ages of 12 and 17, opening the door to become the second vaccine to inoculate adolescents in the United States.

The company said in a statement that studies showed the vaccine was 93% effective in adolescents after one dose and 100% two weeks after the second dose. The study involved more than 3,700 participants 12 to 17.

Moderna said it will submit data from the study to the Food and Drug Administration early next month.

"We are encouraged," Moderna CEO Stephane Bancel said in a statement.

If approved by U.S. regulators, Moderna's vaccine will join Pfizer's as the only two shots approved to prevent COVID-19 in adolescents in the United States. The FDA this month authorized Pfizer's vaccine in children 12 to 15.

Moderna said it has found no major safety concerns using the vaccine in adolescents, and most adverse events were mild or moderate.

"[The vaccine] was generally well tolerated with a safety and tolerability profile generally consistent with the Phase 3 COVE study in adults," Moderna said.

"The most common solicited systemic adverse events after the second dose of mRNA-1273 were headache, fatigue, myalgia and chills."

Moderna said all participants will be monitored for 12 months after the second dose.