The 2025–2026 RSV season in the United States has followed an atypical trajectory. Elevated RSV activity did not begin until December 2025, and the season peaked in late February 2026, roughly 8 weeks later than the 2023–24 season. Peak hospitalization rates were lower than either of the two preceding seasons. As of late March 2026, RSV activity is declining nationally but remains elevated in several regions, particularly the Mountain West.
In response to the prolonged season, 48 of 66 federally funded immunization programs have extended nirsevimab (Beyfortus) eligibility through April 30, 2026.
Disease severity among hospitalized patients has been comparable to recent seasons. The shift is in timing, not in clinical presentation.