(NEXSTAR) – The flu is spreading far and wide ... about 97% have turned up positive for influenza A. Influenza A is further ...

Influenza viruses appear as three types ... Two proteins distinguish strain A subtypes: 15 variants of hemagglutinin (H), and nine of neuraminidase (N). A flu vaccine includes B and the most common A ...

Monthly distribution of influenza A virus subtypes from Jan 2008 to May 2011 and the positive rate in Alberta, Canada. The percentage of positive for IFVA virus subtypes detected from January 2008 ...

The centre said that the city’s dominating flu virus strain had shifted from influenza A subtype H3 seen in the January to March period to subtype H1 recorded in the most recent cases.