Ashley Serrano had tears of relief Saturday when federal health leaders recommended COVID-19 vaccines for preschool children, because she could finally get a shot that protects her 3-year-old from the virus.

And maybe, just maybe, she could burn a vacation day on something other than a preschool outbreak that kept her daughter home.

"I no longer have any vacation time or sick time," the Maple Grove mother said, "and it's only the middle of the year."

Federal recommendations in favor of the Moderna and Pfizer COVID-19 vaccines for children ages 6 months to 5 years set off a scurry on Monday of eager Minnesota parents seeking vaccination appointments — though surveys suggest they are in the minority and that most parents are in wait-and-see mode.

Almost half of parents responding to a Kaiser Family Foundation tracking poll this spring said they would either wait to vaccinate their children 5 and younger or do so only if required. Only 18% of parents were ready to vaccinate newly eligible children right away.

Infectious disease experts with Children's Minnesota encouraged parents to reconsider their hesitation. Serious side effects were rare in the clinical trials of the two vaccines, with the Pfizer shots having 10% of the strength of the adult versions and the Moderna shots having 25%, said Joe Kurland, a Children's vaccine and infectious-disease specialist.

The vaccines weren't as effective in the clinical trials as those for adults, but Kurland said the data was convincing enough that he recommended the shots to relatives and colleagues. More than 200 U.S. children in this newly eligible age range have died of COVID-19. Childhood vaccines are routinely accepted against infectious diseases that cause far fewer deaths.

"I really don't want folks to lose sight and say it's 'just COVID,' " Kurland said. "Because for too many children … this was a fatal infection."

Parents seeking vaccinations said they were mindful of the prolonged dosage schedules. The new Pfizer vaccine comes through three doses spread over 11 weeks, meaning a child who started the series this week wouldn't be fully protected until after the start of school this fall.

Many parents instead sought the Moderna vaccine, which wasn't as effective in comparative data but only requires two doses over four weeks.

Serrano, 39, accepted an evening vaccination appointment in Duluth on Thursday because it was offering a Moderna shot.

A 2-year-old boy named Lincoln was among the first recipients in Minnesota of the newly approved vaccines since they received emergency use authorization last week from the Food and Drug Administration and recommendations this weekend from the Centers for Disease Control and Prevention.

Lincoln was enrolled in the clinical trial for the Moderna vaccine, but his family learned last week that he received the non-medicating placebo and was now eligible to receive the real thing, He received his first dose Monday, said his mother, Nicole, 34, of St. Paul.

Nicole, who declined publication of her last name because of public sensitivity over the COVID-19 vaccine, said the next challenge was finding a regular appointment for her 4-year-old daughter. She wanted the daughter vaccinated before kindergarten and both kids on the same schedule so they could celebrate with an overdue vacation.

"Probably, this fall, we will go to Disney World," the mother said.

The state's Mall of America vaccination site offered 250 appointments to receive the Pfizer vaccine on Wednesday, and they were quickly filled. Other large providers such as HealthPartners and Children's Minnesota are still waiting for supplies to arrive before scheduling appointments later this week or next week.

The vaccination of preschool-age children will be a bit different than it was for adults and routed more through pediatricians and clinic events. Retail pharmacies under state law can't provide vaccine to children younger than 6, though a temporary federal waiver during the pandemic allows them to provide shots to children down to age 3.

Nobody in Quincy Smith's family of four in Edina had tested positive for COVID-19 yet, and he was eager to get his youngest 4-year-old daughter vaccinated to keep it that way.

"I just want to be safe," he said, "so we can go out in public without having to worry about anybody catching it."

By contrast, everybody in Katie Delaney's family of five in Edina has had COVID-19, despite the parents being fully vaccinated. While the three children have received other recommended childhood vaccines, the COVID-19 vaccine seemed like overkill given the immunity from recent infections and their mild illnesses.

"We've had it; we know how our bodies handle it," Delaney said. "None of us have any pre-existing conditions. We handled it well."

Health officials believe strong levels of immunity from recent vaccinations and infections reduced the severity of this spring's COVID-19 wave, despite the prevalence of fast-spreading omicron subvariants. Federal estimates based on a review of blood specimens from medical tests suggest that 61% of Minnesotans have already had COVID-19.

Parents shouldn't wait to see if the next wave is severe, though, said Dr. Shannon Neale, a family medicine physician at Park Nicollet Clinic, because their children won't be able to get the full series of shots quickly enough.

"In a month," she said, "we could have another surge that comes out of nowhere."

Kurland said the ordinary rate of severe COVID-19 and hospitalizations is so small in preschool-age children that it was difficult even in two large trials to produce statistically significant proof that the vaccines offered protection. Both trials relied heavily on data showing that the vaccines produced immune responses similar to those in younger adults.

Pfizer did report 80% protection against symptomatic COVID-19, but that was based on only 10 infections identified in children after their third doses. The trial also started before the emergence of the omicron variant that has shown some ability to infect vaccinated people. The Moderna vaccine was only 51% protective in children younger than 2 and 39% for children age 2 to 5, but its results came during the omicron wave.

Those findings might not have been strong enough outside of a pandemic, but they justify emergency use of the vaccines while COVID-19 remains a widespread threat, he said.

"This is now one of the top five leading causes of death in children under 5 years of age. This is up there with congenital heart disease."