Report of the Webinar on the Analysis of the 2025 Season of Respiratory Virus Circulation in the Southern Hemisphere of the Region of the Americas

This document presents a comprehensive report on the webinar “Analysis of the 2025 Season of Respiratory Virus Circulation in the Southern Hemisphere of the Region of the Americas,” held on 02 October 2025. It summarizes the regional and country-level findings from the 2025 respiratory virus season, including surveillance data, epidemiological trends, and virological characterization of circulating influenza, RSV, and SARS-CoV-2 viruses. The report consolidates presentations from PAHO experts and national teams from Brazil, Chile, Uruguay, Paraguay, and Panama, highlighting key lessons learned, vaccine performance insights, and implications for the 2026 Southern Hemisphere influenza vaccine composition. It also documents country experiences with RSV immunization strategies and includes methodological details, analysis periods, and data sources used across the region.