Against other illnesses, though-including measles, mumps, rubella, pertussis, and the now defeated smallpox-our antibodies stimulated by one infection confer lifelong immunity. That's the principle of vaccination: to stimulate our antibody production without our having to go through the actual experience of the disease, by inoculating us with a dead or weakened strain of microbe.
( Jared Diamond )
[ Guns, Germs, and Steel ]
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