ABSTRACT Public health authorities sometimes have to make decisions about the use of preventive medical measures—e.g. vaccination programmes—which could, if realised, save millions of lives, but could also kill a certain (small) number of those subjected to the measures. According to a rough‐and‐ready utilitarian calculation, such measures should be taken, but there are also possible objections to this view. A liberal objection to the use of mandatory preventive measures which might harm human beings is that people have a right to (...) decide for themselves whether or not they want to participate in the programme. A further objection is based on the claims that first, the authorities are directly killing those who die because of, say, vaccination programmes, and second, directly killing human beings is forbidden (since every human being has a right to live). The latter objection is discussed at length in the present paper. The validity of three doctrines, the doctrines of the double effect, of acts and omissions, and of killing and letting die, are considered with reference to the use of preventive measures, and found inapplicable. The objection is, however, refuted by comparing some hypothetical examples, and the initial utilitarian calculation is reinforced. (shrink)