WASHINGTON (Nexstar) — The former president of the American Academy of Pediatrics said it’s important to vaccinate kids 12-and-older now that the Pfizer COVID vaccine is approved for that age group.

“To date we’ve recorded over 3.8 million children who’ve had COVID-19 and we know that number is probably underestimated,” Dr. Sally Goza said. “And out of that we have had some children who’ve been very sick and we have had children die from COVID.”

In clinical trials the Pfizer vaccine was 100% effective against COVID-19 in kids ages 12 to 15 and it was also effective against new variants of the virus.

“It’s safe and effective for teenagers,” Goza said.

She said children represent about 20% of the new COVID cases over the past few weeks. Kids can also spread the virus even if they’re not showing symptoms.

Pfizer and Moderna are both conducting clinical trials for vaccines in children younger than 12. Goza said the trials are going so well vaccines for younger children may come sooner than expected.

“We’re very excited about that,” she said. “We’re hoping to have something by fall. We’re waiting for those clinical trials to get done. But that would be really wonderful.”

If a vaccine for all school-aged children is not approved by fall, Goza said it will still be recommended for unvaccinated students to wear masks at school. The CDC said only full-vaccinated people can stop wearing masks.