Flu Season is upon us once again. Do you know your flu types, eg. H1N1?
Influenza viruses are divided into 3 categories: A, B and C, depending on their antigen protein type. Antigens are any foreign substance that can stimulate an immune response in our bodies. Type C causes mild respiratory illness. Type B causes seasonal epidemics, and type A can lead to serious worldwide pandemics.
Type A is further divided by the World Health Organization into subtypes based on its surface proteins hemagglutinin (H) and neuraminidase (N). H has 18 known types and plays a role in how the virus binds to host cells. N has 11 known types and helps the virus detach from the cell so it can spread thru the body. That gives 198 possible subtypes from H1N1 to H18N11.
And all of them are called Bird Flu because wild birds are influenza A's natural reservoirs.Only a handful, however, are known to infect humans.
Time to get your flu shot!