The Coming Influenza Pandemic Part III
In Parts I and II I discussed the biology, morphology and genetics of influenza and how the virus makes people sick. In Part III I will talk about various influenza pandemics that have occurred over the past century and the development of Highly Pathogenic Avian Influenzas (HPAI).Seasonal flu does not usually kill many healthy adults and morbidity declines with age. Adults have already been exposed to several strains in their lifetimes and have developed immunity to many of these. Further, as far as scientists are aware, highly pathogenic strains, such as the H5N1 avian flu, do not yet have the ability to easily infect humans. So, why should anyone worry about deadly flu pandemics?
| From Wikipedia |
It is true that H5N1 cannot yet pass easily from person to person. However, as a result of antigenic shift, it could acquire a hemagglutinin that allows easy transmission between people. Alternatively, a flu strain such as H1N1