Local healthcare providers are being asked to continue administering RSV monoclonal antibody treatments to eligible infants through April 30, 2026, after the Washington State Department of Health extended the RSV season due to elevated activity levels.
RSV activity started later than usual this season. Emergency department visits in Washington did not reach the activity threshold until December 2025, compared to October or November in prior years. Hospitalization rates among young children remain elevated.
All infants under 8 months are eligible for treatment with nirsevimab or clesrovimab if they have not already received either medication, are not protected through maternal RSV vaccination given at least two weeks before birth, and have no contraindications. Higher-risk infants between 8 and 19 months in their second RSV season may also be eligible for nirsevimab.
Healthcare providers are asked to assess young children for eligibility and counsel families that RSV is the leading cause of infant hospitalization in the United States. Families with questions about RSV prevention can find more information through the Washington State Department of Health website.