A nurse vaccinates 15-year-old Sherri Trimble at a vaccination clinic at Health First Medical Center in Melbourne, Florida.

Paul Hennessy | SOPA pictures | LightRakete | Getty Images

Moderna said Thursday it had asked the Food and Drug Administration to expand the emergency use of its Covid-19 vaccine in teenagers aged 12-17.

If it were approved by the FDA, it would likely dramatically increase the number of shots available to middle and high school students before the next school year. Pfizer and German partner BioNTech received permission to use their vaccine for 12 to 15 year olds last month.

“We are pleased to announce that we have applied for emergency FDA approval for our COVID-19 vaccine for use in adolescents in the United States,” said Stephane Bancel, CEO of Moderna, in a press release. “We are encouraged that the Moderna COVID-19 vaccine has been highly effective in preventing COVID-19 and SARS-CoV-2 infections in adolescents.”

Moderna’s announcement comes the same day an FDA advisory panel is scheduled to hold a meeting on vaccines in children.

Moderna said on May 25 that its Covid vaccine was 100% effective in a study of 12-17 year olds, making it the second attempt to demonstrate high effectiveness in younger age groups. Moderna’s two-dose vaccine, given every four weeks, is already approved for adults.

The study cited by the company included more than 3,700 young people. No cases of Covid were observed in participants who received two doses of the vaccine, while four cases were observed in the placebo group, according to the company.

No significant safety concerns were identified, and the side effects are generally consistent with those from a previous adult study, the company said. The most common side effects after the second dose were headache, fatigue, muscle pain, and chills, Moderna said.

US regulators are expected to approve Moderna’s application for use on teenagers. The approval process could take about a month, just in time for the fall classes. Pfizer and BioNTech, for example, filed for expanded use of their syringe in teenagers on April 9, and received FDA approval on May 10.

Moderna has already applied for admission for young people in Canada and the EU.

Vaccinating children is seen as critical to ending the pandemic. The nation is unlikely to achieve herd immunity – if enough people in a given community have antibodies to a given disease – until children can be vaccinated, scientists say.

According to government data, children make up approximately 20% of the total US population. About 70 to 85% of the US population must be vaccinated against Covid to achieve herd immunity, medical experts say, and some adults may refuse to get the vaccinations. More experts say herd immunity is becoming increasingly unlikely as coronavirus variants spread.

Vaccinating children can also speed the return of personal learning and extracurricular activities like sports, arts, and music, health experts say.

The Centers for Disease Control and Prevention on May 28 relaxed their public health guidelines for summer camps, saying that fully vaccinated teens do not need to wear masks or stay 6 feet away from others.