The Genome Age is amazing. Until vaccines and antibiotics, diseases largely spread until genes to stop them arose via natural selection among humans or the diseases became less virulent. That process was slow and painful, to say the least. In the 21st Century, modern biotechnology is enabling us to devise the moral equivalent of a species-wide immune system.
For example, German researchers announced in paper in Science being released today that they have identified the structure of the main proteinase molecule of the newly emergent human coronavirus that causes SARS. The proteinase must operate in order for the virus to replicate. Since the human body does not need or make this protein, a chemical that would inhibit its action should safely stop the virus from replicating in people. It turns out that some antivirals already being tested for inhibiting rhinoviruses (common cold viruses) might be quickly tweaked into being effective therapies for people who are suffering from SARS. No need to wait for natural selection.