Indications are that there are still people out there who believe that Charles Darwin was against vaccination.
I have written about this in Review of David Stove: Darwinian Fairytales (essay 1) and Review of Richard Weikart: From Darwin To Hitler (part 1); but I have decided to devote a separate post to this issue.
The famous/infamous passage referred to in claims that Darwin was against vaccination is the following from The Descent of Man, chapter 5, "On The Development of the Intellectual and Moral Faculties During Primeval and Civilised Times":
With savages, the weak in body or mind are soon eliminated; and those that survive commonly exhibit a vigorous state of health. We civilised men, on the other hand, do our utmost to check the process of elimination; we build asylums for the imbecile, the maimed, and the sick; we institute poor-laws; and our medical men exert their utmost skill to save the life of every one to the last moment. There is reason to believe that vaccination has preserved thousands, who from a weak constitution would formerly have succumbed to small-pox. Thus the weak members of civilised societies propagate their kind. No one who has attended to the breeding of domestic animals will doubt that this must be highly injurious to the race of man. It is surprising how soon a want of care, or care wrongly directed, leads to the degeneration of a domestic race; but excepting in the case of man himself, hardly any one is so ignorant as to allow his worst animals to breed.
Indeed, this could sound as if Darwin was against any care of the imbecile, the maimed, the sick, and the poor. Even that he is against vaccination. But let us read the paragraph following this one:
The aid which we feel impelled to give to the helpless is mainly an incidental result of the instinct of sympathy, which was originally acquired as part of the social instincts, but subsequently rendered, in the manner previously indicated, more tender and more widely diffused. Nor could we check our sympathy, even at the urging of hard reason, without deterioration in the noblest part of our nature.
So, it's not as if Darwin suggests that we shouldn't care about the helpless. His point is that the "civilised" races unlike the "savages" have more developed social instincts. This is certainly a debatable proposition; but still, claiming that Darwin was against vaccination is a misrepresentation.