Specifically, there are 18 possible types of a protein called hemagglutinin (H) and 11 types of neuraminidase (N); influenza subtypes are labeled depending on which of these proteins are present.

When broken down by state, most of the country is experiencing elevated respiratory illness, including a few states with ...

A test tube labeled ‘Bird Flu’ on display in front of the American Flag. REUTERS One of the mutations was also seen in another severe case from British Columbia, Canada. No transmission from ...