(WPRI) — If you’re having trouble scheduling a vaccine appointment for your child under the age of 5, there are a few possible reasons why.

COVID-19 shots for children 6 months through 4 years old were authorized earlier this month, after multiple advisory panels and the director of the Centers for Disease Control and Prevention (CDC) signed off.

The vaccines started to arrive in states over the past few weeks.

In Rhode Island, COVID-19 vaccines for children started to become available this week at locations across the state, including doctors’ offices, CVS Minute Clinics, retail pharmacies, federally qualified health centers, and hospitals.

However, not all locations are offering the vaccines to every child in the newly eligible population.

For example, Walgreens is so far only offering the shots to kids ages 3 and up, while some CVS locations with Minute Clinics are offering doses to children 18 months and older.

Although Rhode Island regulations only allow pharmacies to vaccinate children 9 and older, the federal Public Readiness and Emergency Preparedness (PREP) Act supersedes state regulations. The act allows pharmacies to vaccinate children 3 and older against COVID-19.

CVS Minute Clinics are classified as ambulatory care centers, and not pharmacies, which enables the locations to vaccinate children as young as 18 months.

Tara Burke, who heads Northeast Regional Communications for CVS, told 12 News that appointments will be made available on a rolling basis as locations receive supply.

“Our MinuteClinic clinicians, comprised of board-certified Family Nurse Practitioners, Physician Associates, and Nurses, have significant experience providing vaccinations to a younger population as well as private exam rooms, which will make the process easier for kids, parents, and guardians,” Burke explained.

“We recommend reaching out to your child’s pediatrician for children ages 6 to 17 months for vaccination options,” she added.

Joseph Wendelken, a spokesperson for the R.I. Department of Health, noted several reasons for why immunizations for younger children are traditionally administered by a child’s primary care provider.

“For example, a primary care provider knows the child’s medical history best, and immunizations for younger children are an important part of well-child visits, which allow providers to ensure healthy development,” Wendelken said.

Wendelken said the state has been working with primary care practices to get them enrolled as vaccine providers.

“If a practice chooses to not enroll and vaccinate children, the state will connect that practice with a vaccinator that can run a vaccination day for patients,” he said, adding that a provider or practice should do the same.

State-run vaccine clinics are ending operations on June 30 and did not open up vaccines to the newest population.

A spokesperson for Hasbro Children’s Hospital told 12 News the hospital is offering the vaccines to all eligible existing patients within their pediatric primary care and medicine/pediatrics clinics.