Impact of RSV immunization on the rate of pediatric acute otitis media: a time-series analysis

Abstract

Background: Acute otitis media (AOM) is the leading cause of antibiotic prescription in children. Respiratory syncytial virus (RSV) is suspected to play an important role in AOM. The aim of this study was to estimate the impact of RSV immunization on the rate of subsequent AOM in children, as this effect remains unknown.

Methods: We conducted an interrupted time-series analysis based on a French network involving 110 ambulatory pediatricians, trained in pediatric infectious diseases (PARI network). All ambulatory visits for AOM, from June 2017 to February 2025 were included. The main outcome was the monthly rate of pediatric ambulatory visits for AOM in infants aged < 12 months per 1,000 pediatric ambulatory visits over time, assessed by a seasonally adjusted quasi-Poisson regression model. Bronchiolitis and urinary tract infections (UTI) were analyzed over the same period, as positive and negative controls, respectively.

Results: We included 70,452 cases of AOM, 13,284 bronchiolitis and 814 UTI. The rate of AOM per 1,000 visits in infants aged < 12 months significantly decreased after RSV immunization implementation (-23.7%, 95% CI -37.6 to -9.7, p = 0.0014), whereas no significant change was observed in older age groups. We observed similar trends for bronchiolitis. The monthly rate of UTI did not significantly decrease.

Conclusions: RSV immunization led to a strong reduction of AOM rate in infants aged < 12 months. Beyond its efficacy in preventing RSV-related lower respiratory infections in infants aged < 12 months, RSV immunization may contribute to reduce the burden of AOM in children.

Keywords: acute otitis media; nirsevimab; time-series analysis.