Sci Guy: Swine Flu Antgenitic Shift, aka H1N1 (don't want to piss off the farmers)

I always liked the sciguy from the chron, who kept us all well-informed during Ike. Here is a good article on the Swine Flu. and what is a mutation. Someone tell me if I am taking your copyright information, I will just link if so...

Why swine flu scares public officials

One of the most common questions during today's live chat concerned the public health and media reaction to the swine flu outbreak. What, the readers asked, is the big deal with a virus that's infected just 40 Americans and made only one of them sick enough to require
hospitalization?

Annenberg Media See larger version.

It's a very good question.

The answer is a bit more complicated than one could address during a live chat so I thought I'd take a crack at it in a blog entry.

The influenza viruses we're most familiar with evolve from year to year and mutate all the time, a process known as antigenic drift. This drift, a gradual mutation in the genetics of a virus, causes the proteins on the surface of a virus to change, too. If these proteins change enough our immune systems may no longer recognize the flu virus. In years with enough antigenic drift a vaccine may no longer match its target.

However, there's another kind of change to viruses that concerns scientists even more: antigenic shift. During this process at least two different strains of a flu virus combine to form a new subtype. This can happen when two strains — say swine flu and predominantly human influenza — infect the same cell, replicate and assemble a brand new virus.

Here's a helpful graphic which shows how this process can occur.

The current virus in circulation has elements of human, swine, and avian viruses normally found in Europe or Asia, and it may have originated as a result of an antigenic shift. It is for this reason — we are dealing with an entirely new and unknown virus — that has elevated the level of concern for this outbreak.

It remains unclear how virulent the virus will ultimately be in humans, and the hope is that most people who become infected will not become terribly sick, and for those that do there remain ample supplies of antiviral drugs.

But those are far from certainties at this time, so rigorous vigilance and preparation are indeed warranted.