UPDATED: Key Facts about Human Infections with Variant Viruses (Swine Origin Influenza Viruses in Humans)

You might think that inter-species diseases are a thing of the movies, but in reality viruses, bacteria, and fungus jump between the species they attack. The recent H1N1 pig flu virus had genes from bird flu, and when it migrated to humans, it acquired human genes.
Vaccines try to prevent inter-species viruses and include immunity against variations of H1N1, H3N2, H1N2. Viral mutations are not fiction, and vaccination and potent anti-virals are some of our weapons.

Comment on "UPDATED: Key Facts about Human Infections with Variant Viruses (Swine Origin Influenza Viruses in Humans)"

Biotechnology advances have allowed us to understand viruses, bacteria, and other pathogens better than ever before. We use genetic engineering, DNA sequencing, microarrays, PCR, and other genomic and proteomic tools to understand pathogens better.

We've also developed vaccines and potent antivirals and antibiotics that fight diseases. A proof of this is how much longer life expectancy is Today than it was before the 1940's when antibiotics were invented.