(Reuters) – Moderna Inc said on Thursday it has filed for U.S. authorization to use its COVID-19 vaccine in adolescents aged 12 through 17, potentially offering healthcare providers and pediatricians an easier-to-store shot ahead of the return-to-school season in the fall.

The company is the second drugmaker to seek regulatory nod for use of its vaccine in the age group, as the U.S. tries to vaccinate more young people.

Vaccinating children has been considered key to achieving “herd immunity” and while they mostly develop only mild COVID-19 symptoms or no symptoms, younger people still remain at risk of becoming seriously ill, and can spread the virus.

Moderna’s vaccine is already being used in the United States, the European Union and Canada for anyone over 18. The drugmaker said it has also submitted applications to European and Canadian regulators seeking authorization for the shot’s use in adolescents.

Last month, Moderna’s two-shot vaccine was shown to be effective in adolescents aged 12-17 and showed no new or major safety problems in a clinical trial which evaluated the vaccine in 3,732 teenagers.

The U.S. has already authorized Pfizer Inc and German partner BioNTech SE’s COVID-19 vaccine for use in children as young as 12.

More than 7 million teens have received at least one dose of the vaccine in the United States, according to the U.S. Centers for Disease Control and Prevention.

(Reporting by Manojna Maddipatla and Ankur Banerjee in Bengaluru; Editing by Bernard Orr and Shounak Dasgupta)