DES MOINES, Iowa — Children as young as five years old are now eligible for the COVID-19 vaccine, and groups in Iowa are now preparing to administer the shot to them.

The Polk County Health Department will begin vaccinating children aged 5 to 11 age on Thursday with an initial supply of 800 doses of the Pfizer vaccine. Parents can book appointments for children through Polk County Health on Tuesdays, Wednesdays, and Thursdays if there are enough doses to fill the demand.

The health department had a hiccup in the initial rollout, where parents who had appointments scheduled for their kids Wednesday had to reschedule.

“We did not receive vaccines until late Wednesday,” said Polk County Health Department communications officer Nola Aigner Davis. “We wanted to make sure everything from the paperwork to the registration system was ready for us to vaccinate children.”

Hy-Vee pharmacies do not have any appointments available while they wait for shipments of the pediatric COVID-19 vaccine.

Hy-Vee anticipates it will receive doses by Thursday. Once its shipment arrives, parents can book appointments for the childrens’ Pfizer vaccine at Hy-Vee pharmacies.

“Once we do receive them, it’s a pretty quick process to get those loaded in and available for people to start scheduling,” said Hy-Vee assistant vice president of communications Christina Gayman. “We’re just waiting for those shipments to arrive here in the metro.”

The Iowa Department of Health is already warning of a slow roll-out. The department says 26,000 doses are already in the state and another 73,000 should arrive in the next few days.

There are now about 284,000 children in Iowa who are eligible for the COVID-19 vaccine.

Parents can also contact their children’s pediatrician’s office to arrange a vaccination.