[Skip to Content]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address Please contact the publisher to request reinstatement.
[Skip to Content Landing]
Views 1,423
Citations 0
News From the Centers for Disease Control and Prevention
September 5, 2012

Update: Influenza Activity—United States, 2011-12 Season and Composition of the 2012-13 Influenza Vaccine

JAMA. 2012;308(9):854-858. doi:

MMWR. 2012;22:414-420.

3 figures omitted.

During the 2011-12 influenza season in the United States, influenza activity* occurred at low levels during October through December and increased in January and February before peaking in mid-March. Influenza A (H3N2) viruses predominated overall, but influenza A (H1N1)pdm09 (pH1N1) and influenza B viruses also circulated widely. This influenza season was mild compared with recent years, with a lower percentage of outpatient visits for influenza-like illness (ILI),† lower rates of hospitalizations, and fewer deaths attributed to pneumonia and influenza. This report summarizes influenza activity in the United States during the 2011-12 influenza season (October 2, 2011-May 19, 2012) and reports the recommendations for the components of the 2012-13 Northern Hemisphere influenza vaccine.