(CNN) — The White House is ready to “hit the ground running” to vaccinate children aged six months to 5 years old as soon as Pfizer/BioNTech receives emergency use authorization for its COVID-19 vaccine for that age group.

“Our message to parents and families is simple: We are doing everything we can to prepare now. We’re taking all of the best practices and applying all the lessons learned over the last 12 months to ensure getting kids under 5 the protection of (the) vaccine is easy and convenient, and we’ll be ready to start getting shots in arms soon after (the US Food and Drug Administration) and (US Centers for Disease Control and Prevention) make their decisions,” White House Covid-19 response coordinator Jeff Zients said Wednesday.

Pending the FDA’s authorization and CDC’s recommendation, Zients said the administration will be “ready” and will “hit the ground running” to vaccinate the approximately 18 million children under the age of five.

Since the vaccine is specially formulated for this younger age group, the administration is “working closely” with pediatricians, states, local health departments, doctors and pharmacies to ensure the vaccine is available at “thousands of locations nationwide” once it is authorized and recommended, Zients said.

The US has secured “ample doses” and necessary needles and supplies to administer the shots, he added, and “following FDA authorization, we will immediately begin packing and shipping doses to states and health care providers” so they can be distributed to locations parents “know and trust.”

Zients said it would take days from the FDA’s authorization until shots can start going in arms for this age group.

“We cannot begin actually packing and shipping until the FDA authorization, and then there’s the CDC (Advisory Committee on Immunization Practices) process, which generally takes place a matter of days after the FDA. So we’re talking, you know, a matter of several days to a week or so, based on the 5- to 11-year experience, of from FDA authorization to when the first doses will start to be shots in arms. But we’ll move as fast as possible pending the decision of CDC and FDA,” he said.

Zients acknowledged hesitancy among parents. A January Kaiser Family Foundation poll of a nationally representative sample of 162 parents released Tuesday found only 3 in 10 parents say they’ll get their child under 5 vaccinated against Covid-19 right away.

“We know many parents are eager to get their kids the protection of the vaccine. We know others have questions. So we’re working with our partners to ensure all parents have access to the facts and information they need to make the right decision,” Zients said.