U.S. Rep. Charlie Crist is calling on the Food and Drug Administration to authorize a COVID-19 vaccine for children under 12.

In a letter sent to FDA Acting Commissioner Janet Woodcock Monday, Crist, who represents parts of Pinellas County, noted rising impacts of the COVID-19 virus on school-aged children, many of whom remain ineligible for vaccines.

"As of Sept. 2, over five million cases were reported in children, representing 15.1 percent of total nationwide cases. This alarming increase in child cases is in large part driven by the lack of an approved vaccine for children, combined with the return of in-person learning," Crist wrote. "Social isolation, missed school, difficulties finding affordable childcare, and the added stress of the pandemic have profoundly affected families over the past 18 months."

Woodcock released a statement Friday answering questions about the approval process, noting clinical trials are underway but cautioning there is still work to be done.

"Some have stated that they are still enrolling, and some are still administering doses or following participants. This process is expected to include a follow-up period of at least about two months to allow for proper safety monitoring following the administration of vaccine doses for at least half of the clinical trial vaccine recipients," Woodcock wrote.

Still, Crist urges expedience.

"I understand that the Food and Drug Administration (FDA) has been working hard to approve a COVID-19 vaccine that is safe and effective for children under 12. As you can imagine, parents are eager for the FDA to reach a favorable conclusion as soon as possible, consistent with FDA's gold standard scientific process," Crist wrote. "At the same time, many are worried that a vaccine may not be available before the end of the calendar year, given reports that the FDA is requesting manufacturers extend and expand their trials."

"I would urge the FDA to carefully consider the costs and benefits of expanding the trials, rather than using existing data from the initial cohort," he continued.

Currently, vaccines are available to children 12 and older, leaving most middle school students and all elementary and pre-K students unable to obtain vaccinations.

There is a demonstrated desire to change that. Parents across the nation have been scrambling to find ways to vaccinate their young children despite the lack of approved vaccines for kids under 12, The New York Times reported Saturday.

Most seek clinical trials, but some are pleading with pediatricians to use off-label vaccines meant for adults. The FDA discouraged that trend on Friday.

But Crist notes parents are increasingly desperate for additional protection for their children, especially as case counts rise among young children, including an infant death reported just Monday.

"Community leaders, health officials, parents, teachers, and school administrators have been working to create safe, in-person learning environments for our children. While there are things we can do right now to keep children safe, including requiring vaccinations for adults who work with children and wearing masks indoors at schools, nothing compares to a safe, effective COVID-19 vaccine," Crist wrote.

He also reminded children could spread the virus to more vulnerable adults.

"With my home State of Florida struggling with its worst COVID surge to date, and our Governor recklessly playing politics with masks in schools and downplaying the importance of vaccines, there is a devastating cost to delay," Crist continued in his letter. "In Florida, we have seen pediatric ICUs near capacity, with more than 13,000 additional deaths over the last four months. The downside risk to the rest of the country enduring a wave like Florida is frightening. In short, the delta variant has changed the stakes."

While Crist acknowledged a COVID-19 vaccine for younger children should only be approved "should the FDA find that existing safety and efficacy data among COVID-19 vaccines in children meets FDA's rigorous standards," he said, "issuing an emergency authorization for school-aged children under 12 would be prudent."

Children need to be in school and learning in a safe environment. Thank you for your consideration, and I am grateful for all of your work to help us achieve this critical goal.

It's unlikely Crist's letter will move the needle much, however.

"Just like you, we are eager to see our children and grandchildren vaccinated against COVID-19 as soon as possible," Woodcock wrote. But she added, "We have to let the science and data guide us."

Woodcock said she "cannot offer a specific date or timeline" for when a vaccine might be approved for kids under 12. But she said, "the FDA is working around the clock to support the process for making COVID-19 vaccines available for children."

"This process is complex and relies on robust manufacturer trials and data," she said. "We can assure the public we are working as expeditiously as possible to meet this critical public health need, and we very much hope to have pediatric COVID-19 vaccines available in the coming months."