(CNN) — The US could be vaccinating infants, toddlers and preschoolers against Covid-19 within days.

Vaccine advisers at the Food and Drug Administration (FDA) are meeting Wednesday to discuss extending the emergency use authorization of Moderna’s and Pfizer/BioNTech’s shots to those aged six months and older.

It comes a day after the 22 members of the agency’s advisory committee voted unanimously to authorize Moderna’s shot for those aged 6 to 17.

Both companies have reported positive trial results when using their vaccines on younger children. Pfizer found that three child-sized doses appeared to be safe and generated an immune response in trials that’s comparable to the response in older people. Moderna, meanwhile, have reported that two smaller shots appeared to yield a similar immune response as their two-dose vaccine series does in adults 18 to 25.

And the White House is ready for the FDA’s green light. The Biden administration has prepped 10 million doses to be distributed around the country, and expects the first vaccinations to start next week, according to a factsheet shared with CNN this month.

The big question, though, is how quickly parents will take up the opportunity to vaccinate their young kids.

According to the Kaiser Family Foundation’s Vaccine Monitor survey, published last month, only 18% of parents of children under 5 said they would vaccinate their child against Covid-19 as soon as a vaccine was available.

Nearly 40% of parents of young children said they would “wait and see” before vaccinating their child, 11% said they would get the vaccine only if required, and 27% said they would “definitely not” vaccinate their child against Covid-19.

Lack of available information about the program is a factor in that hesitancy, according to the survey; a majority of parents of kids under 5 said they don’t have enough information about its safety and efficacy.

But the US wouldn’t be alone in vaccinating toddlers and preschoolers against Covid-19.

Most countries offering the vaccine to children do so from the age of 5, according to Our World in Data. However, some extend their programs to younger kids — and that’s been the case for some time.

China started vaccinating children as young as 3 last year, and some early real-world data several months later found that its Sinovac and CoronaVac shots did provide some protection to youngsters.

Hong Kong approved vaccinations for 3-year-olds in February amid a surge of infections. And Cuba has been inoculating children aged 2 and older for nine months, in a strategy initially aimed at reopening schools during a wave of cases.

Though Covid-19 more severely affects older age groups, there are benefits to vaccinating the youngest children. Kids can get long Covid and are susceptible to the broad and unpredictable range of symptoms that comes with that condition. Hospitalizations of young children with Covid is uncommon but does occur, and transmission can be high in school settings.

“We have waited a long time for this moment,” White House Covid-19 response coordinator Dr. Ashish Jha said last week.

“If the FDA and CDC recommend these vaccines, this would mark an important moment in the pandemic … kids are better protected, they’re better off, if they’re vaccinated,” he added.

(Copyright (c) 2022 CNN. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)

Join our Newsletter for the latest news right to your inbox