FDA accepts Pfizer application for COVID vaccine in kids under 5, clearing way for June timeline

Pfizer announced Wednesday that it has completed its application to the U.S. Food and Drug Administration for a three-dose COVID-19 vaccine in children aged 6 months to under 5 years old, and the federal agency has accepted the application.

"Pfizer and BioNTech completed a rolling application to the U.S. Food and Drug Administration (FDA) for emergency use authorization (EUA) of the 3-µg [microgram] dose of the Pfizer-BioNTech COVID-19 Vaccine for children 6 months through 4 years of age (also referred to as 6 months to under 5 years of age) on June 1, 2022," the company said in a statement.

The FDA said in a statement that it received Pfizer's request for an EUA.

"We recognize parents are anxious to have their young children vaccinated against COVID-19 and while the FDA cannot predict how long its evaluation of the data and information will take, we will review any EUA request we receive as quickly as possible using a science-based approach," the agency said.

Last month, Pfizer announced that its vaccine for younger children was 80% effective against symptomatic COVID-19.

However, the company said this estimate is preliminary and is subject to change as more data is collected.

The FDA's independent advisory panel, Vaccines and Related Biological Products Advisory Committee, is planning public hearings in mid-June to discuss both Pfizer's and Moderna's vaccines in younger children. The FDA said Wednesday it would hold a VRBPAC meeting on June 15 to discuss both Pfizer and Moderna’s EUA requests for this population -- 6 months through 4 years old for Pfizer and 6 months through 5 years old for Moderna.

Moderna asked the FDA to authorize its two-dose vaccine for children under age 6 on April 28.

During the omicron surge, the company said its vaccine was 51% effective against infection including asymptomatic and mild infection, among those aged 6 months to under age 2, and 37% effective for those aged 2 to 5.

If the FDA decides to authorize vaccines for younger children after the hearing and the Centers for Disease Control and Prevention's independent advisers agree, it could mean vaccines could be available for those under 5 years old by the end of June.

Pfizer's shots are three micrograms each, one-tenth the dose offered to adults, while Moderna's shots are 25 micrograms each, one-quarter of its adult-sized dose.

Although children under 5 are the last age group for which vaccines need to be approved, polls suggest there could be sluggish uptake.

An April 2022 poll from the Kaiser Family Foundation found that only 18% of parents plan to vaccinate their kids under age 5 right away once the vaccine is authorized.

Many are hesitant, with 27% saying they will "definitely not" get their children in this age group vaccinated and 11% saying only if it is required for school.

The remaining 38% said they want to "wait and see" before getting their young children vaccinated.

ABC News' Cheyenne Haslett contributed to this report.