This RSV season was different.
Not because RSV disappeared—it didn’t. Not because the ED was quiet—it wasn’t. But for the first time, we had tools to protect babies before they got sick. And based on newly published CDC data, those tools worked.
📉 What Changed This Year?
The CDC compared hospitalization data for kids <5 years old from the 2024–25 RSV season to pre-pandemic seasons (2018–2020) using RSV-NET and the New Vaccine Surveillance Network (NVSN).
Read the report here
Source:
Patton ME, Moline HL, Whitaker M, et al. Interim Evaluation of Respiratory Syncytial Virus Hospitalization Rates Among Infants and Young Children After Introduction of Respiratory Syncytial Virus Prevention Products — United States, October 2024–February 2025. MMWR Morb Mortal Wkly Rep 2025;74:273–281.
👶 The impact for infants 0–7 months:
- 43% lower hospitalization rate (RSV-NET)
- 28% reduction (NVSN)
- In infants <2 months: reductions reached 52%
🧠 This happened in the middle of a season where older kids actually had higher RSV hospitalization rates than normal. So the virus was there. But the youngest kids—those who received either the maternal vaccine or nirsevimab—were more protected than ever.
🧬 What Was Used?
- Maternal RSV vaccine: given at 32–36 weeks gestation
- Nirsevimab: long-acting monoclonal antibody, given to infants <8 months (and high-risk 8–19 month-olds)
By February 2025, two-thirds of U.S. infants had received either the vaccine (via mom) or nirsevimab. And the biggest drop in hospitalizations? Right in the December–February peak.
🏥 What This Means for the ED
1. We can prevent the sickest babies—from ever showing up.
The steepest drop in admissions was in the <2 month group—those who typically get hit hardest.
→ Protect them early, ideally in the first few days to weeks of life.
2. RSV hasn’t softened—it shifted.
Hospitalization rates for older children (2–4 years) were higher than pre-pandemic years. The virus didn’t weaken. The infants were protected.
3. Timing is everything.
Don’t wait for RSV to spike—prevention has to happen before exposure.
→ Think: fall maternal vaccination and soon-after-birth Nirsevimab protocols
💬 Final Thought
This year’s RSV season gave us our first real test of population-level RSV prevention—and it worked.
The lesson? When we get ahead of RSV, we keep babies out of the ICU, out of the ED, and (hopefully) out of our resuscitation bays.
Let’s build on this momentum.
Dr. Joshua Belfer, MD, is a Pediatric Emergency Medicine physician at the Children’s Hospital of Philadelphia, and is the Founder and Editor-in-Chief of HipPEMcrates. He can be reached at HipPEMcrates@gmail.com.
