Epidemiological Alert Seasonal Influenza in the Americas Region: End of the 2025 Season in the Southern Hemisphere Start of the 2025-26 Season in the Northern Hemisphere - 4 December 2025

Given the start of the season of increased circulation of influenza and other respiratory viruses in the northern hemisphere, the Pan American Health Organization/World Health Organization (PAHO/WHO) recommends that Member States adjust their preparedness and organization plans for health services in anticipation of a possible overload of the health system. PAHO/WHO recommends strengthening surveillance for influenza, respiratory syncytial virus (RSV), and SARS-CoV-2, adopting the necessary prevention and control measures against respiratory virus infections, implementing measures to ensure early diagnosis and appropriate clinical management, especially among the population at high risk of severe disease, guarantee vaccination against respiratory viruses, ensuring high vaccination coverage in high-risk groups, and carry out adequate forecasting and organization of health services to ensure strict compliance with infection control and prevention measures, adequate supply of antivirals and personal protective equipment, as well as adequate risk communication to the population and health professionals.