Disclaimer: I’m in no ways a medical professional, my knowledge of viruses is through reading books and being a virus enthusiast from afar. So please take this idea as just that: an idea.
When fighting forest fires, a common technique used is to light a backfire. That is a fire intentionally set in order to slow, and hopefully stop, an approaching forest fire or grassfire by clearing a burned area in its path It’s a very powerful technique and is used pretty frequently to stop bigger forest fires from spreading.
What if we took this same principal to viruses, including the latest Swine Flu? Of course this would be a last line of defense (it assumes a vaccine can’t be found and manufactured on time). But what about taking people who’ve had the Swine Flu, the less virulent forms, and taking that strain of the virus and exposing the general population to it, ahead of the more virulent strain. This would give the population a chance to create an immunity to it, and it could even stop it dead in it’s track as it hits a wall of immune people on it’s migration.
The downside is that you would be infecting your population with a milder form of a bad virus. Not a good thing. But considering the alternatives, this might not be a bad idea as a last line of defense.
Like I’ve said before, I’m not a medical professional in any sense of the word, just a virus enthusiast. So please take this idea as an idea and nothing more. I don’t know if it would work, and I don’t know that I want to find out if it would work! I just thought it worth mentioning.