What surprises me is that this practice doesn't jive with the "world is a community" view.Many people regard immunization as a personal choice whose risks are independent of the community. The sort of person who decides not to vaccinate often would be appalled at the suggestion that they are bludging on their neighbours and making choices that create risk for everybody.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1
