Health officials in Winnebago County, Illinois continue to see an increase in seasonal influenza into the middle of March reporting 70 cases in week 10 of 2015. This is double the number of seasonal flu cases reported the week prior.

Winnebago County Illinois/Public domain map courtesy of The General Libraries, The University of Texas at Austin
Winnebago County Illinois/Public domain map courtesy of The General Libraries, The University of Texas at Austin

In addition, they also report a shift in the incidence of Influenza from Type A to Type B, according to most recent published data.

According to a local media report, one Rockford hospital has been seeing a dramatic increase in influenza B cases during the past two weeks seeing some six cases per hospital shift.

The 2014-2015 seasonal influenza vaccine contain the same vaccine virus strains as those in the 2013–14 vaccine. Trivalent influenza vaccines will contain hemagglutinin (HA) derived from an A/California/7/2009 (H1N1)-like virus, an A/Texas/50/2012 (H3N2)-like virus, and a B/Massachusetts/2/2012-like (Yamagata lineage) virus.

Quadrivalent influenza vaccines will contain these antigens, and also a second influenza B strain– B/Brisbane/60/2008-like (Victoria lineage) virus.

Related: Flu Shots: Influenza A (H3N2) virus drift affecting vaccination effectiveness