Update: influenza activity--United States and worldwide, 2003-04 season, and composition of the 2004-05 influenza vaccine

MMWR Morb Mortal Wkly Rep. 2004 Jul 2;53(25):547-52.


During the 2003-04 influenza season, influenza A (H1), A (H3N2), and B viruses co-circulated worldwide, and influenza A (H3N2) viruses predominated. Several Asian countries reported widespread outbreaks of avian influenza A (H5N1) among poultry. In Vietnam and Thailand, these outbreaks were associated with severe illnesses and deaths among humans. In the United States, the 2003-04 influenza season began earlier than most seasons, peaked in December, was moderately severe in terms of its impact on mortality, and was associated predominantly with influenza A (H3N2) viruses. This report 1) summarizes information collected by World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories, state and local health departments, health-care providers, vital statistics registries, and CDC and 2) describes influenza activity in the United States and worldwide during the 2003-04 influenza season and the composition of the 2004-05 influenza vaccine.

MeSH terms

  • Global Health
  • Humans
  • Influenza A virus
  • Influenza B virus
  • Influenza Vaccines*
  • Influenza, Human / epidemiology*
  • Influenza, Human / prevention & control
  • Influenza, Human / virology
  • Population Surveillance
  • Seasons
  • United States / epidemiology


  • Influenza Vaccines