Written by Kimiko Dunbar
Spoon Feed
Nirsevimab decreased rates of RSV-positive bronchiolitis and reduced severity and length of stay for hospitalized infants with bronchiolitis who were born after the nirsevimab launch.
Don’t wait, vaccinate
RSV bronchiolitis is the leading cause of hospitalization for children. Some studies have shown increased rates and severity of RSV bronchiolitis following the COVID-19 pandemic. Nirsevimab, a monoclonal antibody to protect infants from RSV, was launched in Sept. of 2023. This multicenter prospective study in France evaluated the impact of nirsevimab on RSV bronchiolitis in 1085 hospitalized infants from Oct. 2023 – Feb. 2024. Infants without nirsevimab had 4.7 times higher odds of RSV-positive bronchiolitis. Nirsevimab significantly reduced oxygen therapy use (20.2% vs. 30.6%, p=0.02) and shortened hospital length of stay (LOS) by one day (p=0.01) in infants born after the nirsevimab launch. However, there was no significant decrease in LOS in the full cohort of infants under 12 months. Using a test-negative design, the study’s estimated effectiveness against RSV hospitalization was 79.5% (95%CI 71.4–85.3; 14.3% vs. 44.9%). Baseline LOS is a bit higher than average in the U.S. (2.5 – 3 days), so it’s hard to know if this is generalizable. However, the potential for impact is arguably even greater than demonstrated in this study, as administration in France was restricted to high-risk infants and neonates.
How will this change my practice?
Nirsevimab is exciting stuff and, in my opinion, has the potential to significantly change the landscape of pediatric admissions. Counseling about RSV prevention with nirsevimab has become a new part of my newborn nursery routine. I’ve found myself emphasizing the danger of RSV (and importance of prevention), with less data to back up the actual efficacy of the nirsevimab, outside of clinical trial data. I’m not sure if the reduced risk of hospitalization and LOS will be enough to sway hesitant parents, especially those who have already declined the RSV vaccination during pregnancy, but it’s a start. We will cover another study of nirsevimab tomorrow.
Source
IMPACT OF NIRSEVIMAB ON RESPIRATORY SYNCYTIAL VIRUS BRONCHIOLITIS IN HOSPITALIZED INFANTS: A REAL-WORLD STUDY. Pediatr Infect Dis J. 2024 Nov 26. doi: 10.1097/INF.0000000000004630. Epub ahead of print. PMID: 39589139
