A few years ago while reading a book on the history of public health in the United States (much more interesting than it sounds, believe me), I became somewhat fascinated with the theory of herd immunity:
A population without an immunisation programme against a disease is vulnerable to all the effects of that disease. Many people will suffer, some die, some may be left with a permanent disability.
Even if there is a vaccination programme, if not enough people get the vaccination, the germ can still infect those who aren’t protected.
When enough people are vaccinated, it is very hard for the germ to find anyone who isn’t vaccinated. Because of this ‘herd immunity’, non-immunised people are protected. They are protected both from catching the disease and suffering any permanent disability.
When enough people are protected, it’s possible for some diseases to disappear forever, as happened with smallpox, and will happen with polio and eventually measles.
When this happens, the World Health Organization can certify the world to be free of that disease and vaccination for that disease will no longer be needed.
In a nutshell, the people who don’t want the vaccine don’t have to get it, because as long as a 90% majority of the population DOES get it, the disease will find it very hard to propagate itself. The vaccinated and the unvaccinated will equally benefit from the actions taken by the vaccinated majority.
Recently I started thinking about this in other terms:
It’s true of firearms too, isn’t it?
Take a block of apartments or houses that’s had problems with burglaries. One of the homeowners/tenants gets fed up and buys a gun. The next time the building gets broken into, the packing tenant stops the burglary by keeping the criminal secure until the police can arrive. That person’s neighbors will react in one of two ways:
1)buy a gun for themselves; or
2)not buy a gun.
However, once word gets out that the folks at 1234 Average Street are armed, criminals will stay away. (Better to hit a high-class neighborhood full of gun-hating liberals.) The disease of crime finds it very hard to put up a fight when there is active resistance.
The armed and the unarmed will equally benefit from the actions of the armed.
But wait! It gets better, because it does not require a majority to be armed as it does with vaccinations. Even if none of the neighbors of the hypothetical person I described in my scenario buy a gun, it will be known that at least one person in the building is not afraid to use his firearm. The more, the better, obviously.
The anti-gun Million Moms types shouldn’t be fighting gun owners. They should be thanking them.
(UPDATE: Ben Kepple correctly reminds me, that this is of course, why concealed-carry laws work: they help prevent robberies and muggings in addition to burglaries. A mugger will think twice about holding up someone who may be armed.)
(UPDATE, AGAIN: The public-health book I referred to earlier is Ed Regis’ Virus Gound Zero. Excellent read.)