But first let’s go back and revisit last years 2012–13 influenza season. In the United States, influenza activity increased through November and December before peaking in late December. Influenza A (H3N2) viruses predominated overall, but influenza B viruses and, to a lesser extent, influenza A H1N1 (2009 pandemic virus) viruses also were reported in the United States. This influenza season was moderately severe, with a higher percentage of outpatient visits for influenza-like illness (ILI), higher rates of hospitalization, and more reported deaths attributed to pneumonia and influenza compared with recent years.
And the winner is…(drum roll please)…
- A(H3N2) virus antigenically like the cell-propagated A/Victoria/361/2011 virus (A/Texas/50/2012)
- B/Massachusetts/2/2012-like (B/Yamagata lineage) virus. A/Texas/50/2012 is an egg-propagated A(H3N2) virus
- All of the above plus
- B/Brisbane/60/2008-like (B/Victoria lineage) virus (1).
And now you know!