NEW YORK — Moderna said on Wednesday that its coronavirus vaccine works in children ages 6 months to 6 years old, and that it plans to seek approval from global health regulators.

The pharmaceutical company said in a statement on Wednesday that a COVID-19 vaccine study on children ages 6 months to 6 years old was successful. The $75 billion vaccine-maker described the results in a press release but has not published the results in a medical journal.

No COVID-19 vaccine has been OK’d for use in children under the age of 5 years old in the US. Last month, Pfizer postponed its own authorization application for young children, saying it would wait for additional data on a three-dose course expected in early April.

Moderna tested a two-dose regimen with 25 microgram shots, still a fraction of the original 100 microgram dose given to adults, but still far higher than what Pfizer had been testing with a 3 microgram dose. Moderna said its study involved about 6,700 children in two groups: ages 6 months to under 2 years old and 2 years to under 6 years old.

Despite claims of success, the efficacy results were modest. Moderna said the vaccine was about 44% effective at preventing symptomatic infections in children between 6 months and 2 years old. For children between 2 and 5 years old, the two-dose regimen was 38% effective at preventing symptomatic infection.