Influenza activity--United States and worldwide, May 18-September 19, 2008

Abstract

During May 18-September 19, 2008, influenza A (H1), influenza A (H3), and influenza B viruses were detected worldwide and were identified sporadically in the United States. This report summarizes influenza activity in the United States and worldwide since the last update and reviews the new influenza vaccine recommendations for the upcoming season. Influenza viruses circulating this summer appear antigenically similar to the strains included in the 2008-09 influenza vaccine. Recent antiviral resistance data are limited, but oseltamivir resistance among influenza A (H1N1) viruses might persist during the 2008-09 influenza season.