Worst Case Scenario for the Fall

The virus that has caused the current swine flu -- H1N1 -- seems plenty capable of jumping from one host to another, but lacks lethality -- meaning that most infected people recover quickly. But the worst case scenario for the fall is if this virus genetically combines with the avian flu virus -- dubbed H5N1. Experts are exploring what might happen if these two combine to produce a virus that has both great transmissibility and great lethality. Read the story here.

It is useful to remember the product of a virus that is lethal and a virus that is highly transmissible is not necessarily a virus that has both those characteristics -- even though that may seem logical. Mutations often lead to evolutionary dead ends; they produce virus variants that are incapable of survival. Still, the scary possibility is worth pondering as a worst case scenario.