Vaccine makers Pfizer (PFE  ) and BioNTech (BNTX  ) announced that they will complete their emergency use authorization (EUA) submission this week for children under the age of 5 following strong results from a three dose study.

The companies said that a three dose primary series of 3 micrograms in young children performed almost as effectively as the pair's two dose series for other age groups. The vaccine demonstrated 80.3% efficiency at preventing COVID infections, with the study taking place while the Omicron variant was the dominant circulating viral strain.

"Our COVID-19 vaccine has been studied in thousands of children and adolescents, and we are pleased that our formulation for the youngest children, which we carefully selected to be one-tenth of the dose strength for adults, was well tolerated and produced a strong immune response," Said Albert Boula, chairman and chief executive officer at Pfizer, in a press statement. " "These topline safety, immunogenicity and efficacy data are encouraging, and we look forward to soon completing our submissions to regulators globally with the hope of making this vaccine available to younger children as quickly as possible, subject to regulatory authorization."

The companies' data is based on a study of 1,678 children who received a third dose at least two months after their second dose when Omicron was circulating. Children ages 6 months to 4-years-old are the last group in the United States to have a COVID vaccine authorized.

Moderna (MRNA  ) recently completed its submission for its COVID vaccine four young children between the ages of 6 months to under 6 years. The company's two 25 microgram dose primary series was about 44% effective at preventing infection in children age 6 months to 2 years and roughly 38% effective for children aged 2 years to under 6 years. Moderna previous said is had begun a study of a third dose booster shot in this age group.

The U.S. Food and Drug Administration's (FDA) vaccine advisory committee is set to meet on June 14 to review Moderna's EUA application for children and adolescents between the ages of 6- to 17-years-old. The committee said the following day it will review both Pfizer's and Moderna's applications for children under 6-years-old.

The FDA said in a statement it expected to complete its review of both companies' vaccines for the youngest Americans as soon as possible.

"We know parents are anxious for use to determine if these vaccine are safe & effective," the FDA wrote on Twitter (TWTR  ). "We are working as quickly as possible to carefully review all the data."