Update: influenza activity--United States and Worldwide, 1995-96 season, and composition of the 1996-97 influenza vaccine.

To monitor influenza activity and to detect antigenic changes in the circulating strains of influenza viruses, CDC conducts surveillance in collaboration with the World Health Organization (WHO) and its international network of collaborating laboratories and with state and local health departments in the United States. This report summarizes surveillance for influenza in the United States and worldwide during the 1995-96 season and describes the composition of the 1996-97 influenza vaccine.