The United States of America President Joe Biden on Friday hailed the approval of Pfizer and Moderna vaccines against COVID-19 for younger children as a "huge relief."

"Today is a day of huge relief for parents and families across America," Biden said in a statement, adding that it will help "our nation continue to move forward safely."

The U.S. Food and Drug Administration granted emergency authorization Friday for the use of Pfizer and Moderna in children under five.

The nation's vaccination campaign started in December 2020 with the rollout of adult vaccines from Pfizer and Moderna, with health care workers and nursing home residents first in line. Teens and school-age children were added last year.

(With input from agencies)