LOS ANGELES, April 28 (Xinhua) -- Moderna on Thursday asked the U.S. Food and Drug Administration (FDA) to authorize its COVID-19 vaccine for children 6 months to under 6 years of age.

       The two-dose vaccine was about 51 percent effective against infection from the Omicron variant in children from 6 months to under 2 years old, and about 37 percent effective among 2 to under 6 years old, according to Moderna.

       Children under 5 are the only group in the United States ineligible to receive a COVID-19 vaccine.

       If authorized by the FDA, Moderna's vaccine for children 6 months to under 6 years of age is given as two 25-microgram doses four weeks apart. The dosage is a quarter of that given to adults.