RSV Is Spreading Faster Than Flu Right Now—Here's What's Happening

Respiratory syncytial virus (RSV) is now spreading faster than influenza across the United States, with infections growing in 24 states as of early February 2026. While flu activity remains elevated overall, the trend is shifting—flu cases are declining in 15 states, whereas RSV continues its upward trajectory in nearly half the country. This changing pattern highlights how multiple respiratory viruses can take turns dominating during winter months, each presenting different risks depending on age and health status.

Why Is RSV Suddenly Surging While Flu Slows Down?

The answer lies in how respiratory viruses naturally cycle through populations. Influenza peaked earlier this season, with positive lab tests dropping from 32.9% to 24.7% in recent weeks, and outpatient visits for respiratory illness declining for the first time this season. Meanwhile, RSV has been climbing steadily, with emergency department visits and hospital admissions for children aged zero to four years increasing this week. Both viruses spread through respiratory droplets, but they don't follow identical transmission patterns—RSV tends to hit hardest in winter and early spring, particularly affecting young children and older adults.

The CDC estimates transmission using a metric called Rt, which measures whether infections are growing or declining in real time. As of February 3, 2026, RSV showed growth or likely growth in 24 states, compared to just nine states for influenza. This doesn't mean flu is disappearing—it simply means RSV is now the faster-spreading threat in most regions.

Which Groups Face the Highest Risk Right Now?

RSV poses the greatest danger to vulnerable populations, though the risk varies by age and health status. The CDC notes that RSV has long been a leading cause of hospitalizations for children, and current data show concerning trends in the youngest age groups. However, RSV also affects older adults and people with chronic conditions like heart or lung disease. In contrast, influenza continues to pose serious risks across all age groups, with eight flu-related pediatric deaths reported in a single week, bringing the season total to 17 deaths in children.

Vaccination coverage for both viruses remains suboptimal, according to CDC surveillance data. This is particularly concerning given that RSV vaccines are now available for older adults, and flu vaccines remain the primary defense against influenza—though this season's flu vaccine effectiveness ranges from 31% to 40% depending on the strain.

What Should You Know About Current Respiratory Illness Activity?

The CDC tracks respiratory illness activity using emergency department visits and wastewater surveillance to provide early warning signs of outbreaks. Current activity levels vary significantly by region and pathogen. Here's what the data shows across the country:

• Influenza Status: Declining or likely declining in 15 states, growing or likely growing in nine states, and stable in 23 states as of February 3, 2026.
• RSV Status: Growing or likely growing in 24 states, declining or likely declining in 11 states, and stable in 12 states, making it the most actively spreading respiratory virus nationwide.
• COVID-19 Status: Remaining low at the national level but showing signs of increase, with growth or likely growth in 13 states, decline in nine states, and stability in 25 states.

The CDC also monitors wastewater for traces of infectious diseases, which can serve as an early warning system even before people develop symptoms or seek medical care. This surveillance method has become increasingly valuable because it captures infections that might not result in emergency department visits.

Hospital admissions paint a clearer picture of current burden. Flu hospitalizations rose to 39,945 patients in a single week, up from 33,301 the previous week. While this represents a significant number of people requiring inpatient care, the trend suggests flu activity may be peaking in many regions. RSV hospitalizations, particularly among young children, are also climbing, though comprehensive hospitalization data across all age groups remain limited in current reports.

The CDC expects the 2025-26 respiratory disease season to produce a similar number of hospitalizations from COVID-19, influenza, and RSV combined as the previous season. This projection underscores that while individual viruses may wax and wane, the overall burden of respiratory illness remains substantial through winter and into spring.

For now, the key takeaway is straightforward: RSV is the virus gaining ground fastest across the country, even as flu cases begin to decline. Staying informed about which viruses are circulating in your region, maintaining vaccination status, and practicing basic respiratory hygiene—like hand washing and staying home when sick—remain the most effective ways to protect yourself and vulnerable people around you.