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A retrospective cohort study of 245,498 infants born within the Kaiser Permanente system in Northern California between 2011 and 2022 found that maternal influenza vaccination during pregnancy significantly reduces the risk of infant influenza in the first 6 months of life, as published in Obstetrics & Gynecology. Overall, maternal vaccination was associated with a 44.4% reduction in influenza incidence among infants (95% confidence interval, 31.4–54.9%). Effectiveness varied by timing of the vaccine. Vaccination during the second trimester reduced influenza risk by 51.5% and in third trimester by 59.3%. As the infant grows, protection wanes. Authors found that maternal vaccination significantly reduced the risk of infant influenza by 51.4% for infants aged 0 to 60 days, by 55.5% for infants aged 61 to 120 days, and by 28.5% for infants aged 121 to 180 days. Among the study population, 46% of infants were born to vaccinated mothers, with vaccination occurring in the first trimester for 25.7% of moms, second trimester for 42.1%, and third trimester for 32.2%. Based on data through June 21, 2025, a total of 253 influenza-associated pediatric deaths have occurred for the 2024-2025 season as reported to the Centers for Disease Control and Prevention (CDC)—the highest number of pediatric deaths reported in any non-pandemic influenza season since the condition became reportable in 2004. However, infants under 6 months aren’t individually tracked in CDC’s national flu case counts.
Top of the charts: Exclusive data analyzed for JUCM from the Experity EMR shows that influenza testing was the top test delivered in urgent care for patients of all ages, accounting for 77.6 million tests in 2024 among 3,000 centers across all 50 states.