And now, an Idea …
I’d just like to add – on the same theme.
When there was a SARS outbreak in China, and people were dying from it.
In London I sat on a bus and a Chinese person, was so sick, continually sneezing, it was quite extreme.
No cases of SARS were reported in the UK (or I think outside China).
No prejudice to Chinese intended ..
According to what I’ve been reading, the fall out of the new flu in Mexico is vastly different from that in the U.S. In Mexico, it has been very deadly. In the U.S. it has not been deadly.
Read this: New U.S. swine flu cases spread pandemic fears
Now, imagine this.
How could one develop a flu that would kill one population and not kill another population, assuming the flu could cross borders without any trouble? It might not be very hard to do.
Manufacture two very similar variations on the same basic flu such that one is more lethal than the other while an immunity to one provides and immunity to the other. Release the more deadly version in the targeted area and the less deadly version in the area you wish to protect. Make sure to release both versions simultaneously.