HARRISBURG, Pa. (WHTM) — The effort to vaccinate younger kids in Pennsylvania against COVID-19 is in full swing, just three days after shots were approved for 5 to 11-year-olds. UPMC says in just the first 24 hours, parents made 10,000 vaccine appointments for kids in that age group.

UPMC began giving out the lower-dosage Pfizer vaccines to those younger kids on Wednesday, and says that’s not a moment too soon.

Health experts say in October, 10% of COVID cases nationwide were in kids 5 to 11-years-old.

UPMC wants to get vaccines to as many kids as possible, in addition to offering them through its providers and pediatric offices. It’s working to set up community-based and school-based clinics.

Some parents have raised concerns over myocarditis, which is inflammation of the heart muscle. Doctors said it is very rare.

“The rates of myocarditis are much higher for people who get COVID-19 and usually more severe than those who receive the vaccine,” Dr. Alejandro Hoberman, president of UPMC Children’s Community Pediatrics said.

Doctors at UPMC also took the time to once again recommend COVID-19 vaccines for all pregnant women they say only one-third of pregnant women in the U.S. are vaccinated.