COVID shots may be days away from becoming available to infants and toddlers with expert panels set to evaluate both Pfizer-BioNTech and Moderna pediatric vaccines this week. But it's unclear how much the number of vaccinated kids will move.

Why it matters: For anxious parents of America's littlest kids, this is a big moment. Children younger than 5 are the last group without access to the shots.

Driving the news: This week, both FDA and the CDC vaccine advisory boards will meet to discuss the vaccines, which could ultimately lead to emergency use authorization and a recommendation.

But even as the Biden administration prepares to activate a rollout of the vaccines in pediatricians' offices and clinics nationwide, it's unclear how many parents will actually to get their kids vaccinated.

• 8.2 million, or just 29%, U.S. children ages 5-11 completed the 2-dose vaccination series as of June 8, according to CDC data.
• The Omicron variant already spread through many daycares and schools, leaving kids who contracted the virus with some level of immunity and reducing urgency for the shots.
• Many Americans desperately want to put the pandemic behind them and face fewer rules like vaccine mandates, which might have prompted a quick response.
• Just one in five parents said they were planning to immediately get their young children vaccinated, according to a Kaiser Family Foundation survey released last month. At the same time, more than a third said they wanted to "wait and see" how other children responded before getting their own child vaccinated.
• But, but, but: A Harris Poll found some parent found nearly half of parents who were unvaccinated themselves said they'd get the vaccine for their little kids, up from 35% in early February.

What they're saying: "I suspect if the vaccine was available two years ago, the vaccination rates would get much higher," Paul Offit, director of the Vaccine Education Center at Children's Hospital of Philadelphia and a member of the FDA advisory board, told the Philadelphia Inquirer.

Yes but: Experts are urging parents not to "wait-and-see" on these shots, particularly since it could take time to administer the series before the return to school and potential fall surges.

• "You can't predict when the next surge is, and the body needs time to mount an immune response," Annabelle de St. Maurice, a pediatric infectious-disease specialist at UCLA Health, told the Atlantic.

Zoom in: As we've previously seen, there are some key differences between the Pfizer and Moderna mRNA shots.

• Moderna is seeking an EUA for a two-dose series of 25-micrograms each delivered four weeks apart. FDA staff said Friday the vaccine was found to be safe and effective in children, with clinical data showing efficacy was 51% for children ages 6 months to 2 years and 37% in those ages 2 to 5.
• Pfizer is seeking an EUA for a three-dose series of shots for kids ages 6 months through 4 years old. The first two doses, a tenth of the dose adults get, would be delivered within three weeks of each other and the third shot would come two months later. Pfizer's shot has already been cleared for everyone 5 and over.
• The FDA on Sunday said Pfizers shot was found to be safe and effective. Data released by Pfizer last month data indicates its vaccine was more than 80% effective at eliciting a strong immune response in kids under 6 although the study was too small to assess the efficacy of their shots, the New York Times reported.

What to watch: If all goes according to plan, shots could become available as soon as June 21 since many doctor's offices may be closed for the federal Juneteenth holiday on June 20, officials said.

• Pre-ordering for 10 million vaccines was opened up to states earlier this month to ensure patients could access either the Pfizer or Moderna shots — although both may not be available in all areas right away.
• In addition to having vaccines available at health systems and pediatricians' offices, shots are expected to be available in clinics located at museums, libraries, and child-care sites.
• Officials could not comment on whether discussions about variants and changes for vaccines that are under development would impact children's vaccinations.

The bottom line: With previous strains of COVID seemingly less dangerous for kids — and with many already through a bout with the virus — parents may be reluctant to get a shot right away for their kids under 5.

• But with the lingering threat of long COVID, and questions about what future strains might bring, experts say parents should opt in as soon as it becomes available.