PAHO warns Americas to prepare for overlapping influenza and RSV waves this winter

A crowded respiratory season

Health authorities across the Americas are being urged to strengthen preparedness as seasonal influenza and respiratory syncytial virus (RSV) circulate simultaneously, a combination that can strain emergency departments and inpatient capacity during winter. In an alert issued in January, the Pan American Health Organization (PAHO) advised countries to stay vigilant, update response plans, and anticipate potential spikes in visits and hospitalizations as multiple respiratory viruses spread at once.

PAHO noted that influenza activity has been rising since October 2025, with A(H3N2) predominating, while RSV circulation is also trending upward. The agency said concurrent waves can create operational challenges because patient surges arrive quickly, pediatric capacity can tighten, and staffing and supplies may be stretched across multiple service lines at the same time.

What PAHO recommends

• Adjust health service response plans to manage possible simultaneous increases in influenza and RSV cases.
• Prioritize influenza and COVID-19 vaccination for at-risk groups such as older adults, young children, pregnant people, those with chronic conditions, and health workers.
• Implement RSV prevention strategies, including maternal vaccination and long-acting monoclonal antibodies for newborns and infants where recommended.
• Strengthen risk communication so the public understands how to reduce spread and when to seek care.

The guidance emphasizes practical prevention steps—staying home when feverish, improving hygiene, and using masks indoors if symptomatic—along with rapid clinical assessment for severe cases. PAHO’s advisory also aims to help health systems avoid being caught off guard by synchronized peaks that can fill beds faster than the more staggered patterns seen in milder seasons.

The central message: plan for overlap, not sequence—because viruses do not take turns.

For U.S. readers, the alert aligns with a broader winter reality: respiratory illness burden is shaped not just by one pathogen but by combined circulation, shifting immunity, and timing. Preparing early—through vaccination, clear triage pathways, and surge plans—can reduce avoidable hospital strain, particularly in pediatric settings where RSV impact can be most pronounced.