(CNN) Moderna announced interim results of its Covid-19 vaccine for children younger than 6 on Wednesday.
The company said two 25-microgram doses of its Covid-19 vaccine for children ages 6 months through 5 years old provided a similar immune response to two 100-microgram doses for adults ages 18 to 25, indicating that the benefit conferred to young adults is also conferred to young children.
The two doses of vaccine are given to children 28 days apart.
The data showed "a robust neutralizing antibody response" and "a favorable safety profile," according to a company news release issued Wednesday.
Based on the data, Moderna said it will ask the US Food and Drug Administration to authorize the use of the vaccine in this younger age group in the coming weeks.
"Given the need for a vaccine against COVID-19 in infants and young children we are working with the U.S. FDA and regulators globally to submit these data as soon as possible," Moderna CEO Stéphane Bancel said. "We believe these latest results ... are good news for parents of children under 6 years of age."
The vaccine was not all that effective at preventing Covid-19 infections caused by the Omicron variant, which predominated in the US during the study. For children ages 6 months through 1 year old, the efficacy was 43.7%. For children ages 2 through 5, the efficacy was 37.5%. Moderna said the lower efficacy was still statistically significant and consistent with how vaccinated adults have fared with the Omicron variant.
Moderna said it is preparing to evaluate the potential of a booster shot for all children 6 months and older, which would target the original strain of the virus as well as the Omicron variant.
The data is based on a group of 6,900 children ages 6 months through 5 years old. The majority of adverse reactions were mild or moderate, and were more frequent after the second shot. Moderna said no deaths and no cases of myocarditis or pericarditis were reported. Myocarditis is inflammation of the heart muscle and pericarditis is inflammation of the heart lining.
Moderna also announced that it has initiated a submission to the FDA for emergency use authorization of the company's Covid-19 vaccine for children ages 6 through 11 years old. Children that age would get two shots of a larger 50-microgram version of the vaccine. Moderna also said it provided the FDA with additional follow-up data on its vaccine for children ages 12 to 17. Children that age would get two shots of a larger 100-microgram version of the vaccine.
Last month, the FDA postponed a meeting of its vaccine advisers to consider Pfizer/BioNTech's Covid-19 vaccine for children younger than 5, and requested additional data on third doses. The companies have said they expect that data to be ready by early April.