BOSTON (WPRI) — Massachusetts children as young as 6 months old can get a COVID vaccine this week.

Gov. Charlie Baker announced the state’s plan to begin rolling out the shots on Tuesday after the Centers for Disease Control and Prevention (CDC) approved the vaccines for infants, toddlers and preschoolers.

Pfizer and Moderna got the green light Friday from the Food and Drug Administration (FDA) and Saturday from the CDC.

Parents in Massachusetts can call their primary care provider’s office directly for an appointment or can go online through the state’s VaxFinder website.

In Rhode Island, health officials told 12 News due to the logistics of ordering and administering the vaccines, the shots likely won’t be available until late June or early July.

Pfizer’s vaccine is for children 6 months to 4 years old. The dose is one-tenth of the adult dose, and three shots are needed. The first two are given three weeks apart, and the last at least two months later.

Moderna’s vaccine is two shots, each a quarter of the adult dose, given about four weeks apart for kids 6 months through 5 years old. The FDA also approved a third dose, at least a month after the second shot, for children who are immunocompromised.

Former FDA Commissioner Dr. Scott Gottlieb says he expects the vaccine rollout for children to go more slowly than for other age groups because of the need for people who are “specially trained.”

“It’s going to take a little bit more time to get the vaccine into those local settings because it’s more difficult to vaccinate a child who is very young,” Gottlieb said on CBS’ Face The Nation.

Roughly 18 million kids nationwide are now eligible for the shot, but it remains to be seen how many will ultimately get the vaccines. Less than a third of children ages 5 to 11 have done so since vaccination opened up to them last November.

“It’s continued to concern me that we haven’t seen a lot of uptake among children, generally,” Gottlieb said.

“There are surveys showing that about 20% of parents plan to vaccinate children under the age of five, I suspect it may end up being lower than that,” Gottlieb continued. “I think as prevalence declines going into the summer, a lot of parents may choose to take a wait and see attitude and reconsider this in the fall.”