infectious diseases
Influenza Vaccine
Introduction
Based on recommendations by the World Health Organization and the Centers for Disease Control and Prevention (CDC), vaccines for Influenza are modified annually to include the most prevalent strains (usually 2 strains of influenza A and 1 or 2 strains of influenza B). Sometimes slightly different vaccines are used in the northern and southern hemispheres. For more information, see the Centers for Disease Control and Prevention (CDC)Influenza Advisory Committee on Immunization Practices Vaccine RecommendationsandCDC: Influenza Vaccination. For a summary of changes to the 2023 adult immunization schedule, see the Advisory Committee on Immunization PracticesRecommended Adult Immunization Schedule, United States, 2023: Changes to the 2023 Adult Immunization Schedule. (See also Overview of Immunization .) 