Population Changes in the Rate of RSV-Associated Hospitalizations and Emergency Department Visits Among Infants After Combined Introduction of Infant Monoclonal Antibody and Antenatal Vaccine in Washington State, USA
- Presentation Day/Time: Thursday, April 23, 11:00 AM
- Presenter: Julia Bennett, PhD, MSPH, Washington State Department of Health
The Issue
- RSV is the leading cause of infant hospitalization in the U.S. A long-acting monoclonal antibody (nirsevimab) for infants aged 0–7 months and an antenatal RSV vaccine (RSVpreF) became available in Washington State in autumn 2023.
What We Did
- We estimated the combined population-level impact of these products on the relative rate of RSV-associated hospitalizations and emergency department (ED) visits among infants during the first two respiratory seasons of use.
What We Found
- During the first year of limited use of RSV prevention products, our estimate did not indicate a significant decline in the rate of RSV-associated hospitalizations and ED visits among children aged 0–7 months. However, in the second year of use, we estimated a 43.0% relative decline in the rate of RSV-associated hospitalizations and ED visits among aged children 0–7 months.
What This Means
- Infant nirsevimab and antenatal RSVpreF vaccine were associated with reduced burden of RSV-associated hospitalization and ED visits in infants aged 0–7 months, which supports continued use of these products in the state. Increased coverage will likely lead to additional declines in severe disease burden.
