A new analysis from the Centers for Disease Control and Prevention (CDC) finds that the 2024-25 COVID-19 vaccine substantially reduced the risk of emergency department (ED) and urgent care (UC) visits among US children and adolescents. The findings, published yesterday in Morbidity and Mortality Weekly Report, draw on data from more than 98,000 pediatric cases in nine states.
Researchers looked at data from electronic health records to assess how well the updated vaccines, which target the Omicron JN.1 and JN.1-derived sublineages, protected against COVID-related ED and UC visits from August 2024 to September 2025. The test-negative, case-control study measured the added protection provided by the 2024-25 dose in children and adolescents, many of whom already had some immunity from prior infection, previous vaccination, or both.
76% effectiveness against severe disease in young kids
Among children aged 9 months to 4 years, vaccine effectiveness (VE) against COVID-associated ED/UC visits was 76% during the first 7 to 179 days after vaccination. Protection remained stable through 299 days.
These VE estimates are similar to or higher than those observed in adults during the same season, and they exceed that reported in young children during the 2023-24 season. According to the authors, the higher 2024-25 estimates might be related to different infection patterns compared with previous seasons or fewer changes in circulating variants in 2024-25.
During the 2024-25 season, hospitalization rates among US infants aged 6 to 11 months were higher than those of all adult age-groups except those aged 65 years and older. These findings underscore the potential benefits of COVID-19 vaccination in eligible infants, note the authors.
In children and adolescents aged 5 to 17 years, the 2024-25 vaccines reduced the risk of an ED/UC visit by 56% during the first 7 to 179 days after vaccination. Protection declined slightly to 45% when the window was extended from 7 to 299 days.
Strong effectiveness as federal recommendations rolled back
The authors acknowledge several limitations, including ED and UC visits for non–COVID-related reasons, potential misclassification of vaccination status, incomplete documentation of prior infections, and limited ability to measure VE against hospitalization due to fewer severe cases in children this season.
Still, the results suggest that the 2024-25 vaccines provided meaningful additional protection for children and teens, including for those who had background immunity. The findings come as longstanding federal vaccine recommendations are being reconsidered and, in some cases, rolled back. This year, under the guidance of US Health and Human Services Secretary Robert F. Kennedy Jr., a noted vaccine skeptic, the federal government removed its recommendation that healthy pregnant women and children should receive the COVID vaccine.
