Pfizer’s says its COVID-19 vaccine was 73% effective in protecting children younger than 5 as omicron spread in the spring.
Vaccinations for babies, toddlers and preschoolers opened in the U.S. in June after months of delay.
Only about 6% of youngsters ages 6 months through 4 years had gotten at least one dose of a COVID-19 vaccine by mid-August.
Health authorities authorized tot-sized vaccine doses by Pfizer and BioNTech based on a study showing they were safe and produced high levels of virus-fighting antibodies.
The new update analyzed COVID-19 diagnoses between March and June in Pfizer’s ongoing study of the three-dose vaccine.