This season’s flu vaccine appears to have been less effective in preventing emergency room visits for some children compared to last year, according to a new study from the Centers for Disease Control and Prevention (CDC). However, the vaccine still provided strong protection against hospitalization.
The CDC’s Morbidity and Mortality Weekly Report, released Thursday, found that flu vaccination reduced the risk of hospitalization by at least 63% for children and 41% for adults—considered high effectiveness for flu vaccines.
However, when it came to preventing outpatient visits, such as trips to urgent care clinics or emergency rooms, the vaccine’s effectiveness dropped to 32% for children and adolescents, a notable decline from 67% in last year’s estimates.
Researchers believe the difference may be linked to a strain of the flu virus known as H3N2. The U.S. Flu VE network, which tracks vaccine effectiveness across various health systems, found no statistically significant protection against this strain in outpatient settings.
“The U.S. Flu VE network did not find statistically significant VE against influenza A(H3N2) in the outpatient setting among child and adolescent patients or among adult patients,” the study’s authors wrote.
Despite the decline in outpatient protection, health officials continue to emphasize the importance of flu vaccination, particularly for preventing severe illness and hospitalization.