I was recently asked to give a talk on vaccination and potential conflicts between the rights of parents and the interests of their children. A few years back when my boys were bonny wee things some bohemian friends announced that they would not be vaccinating their children, they would rely instead on homeopathic remedies. Although this was not long after the MMR scandal they were not provoked into their decision by media tittle-tattle, the father at least having long been a champion of the little white pills—and a healthy chap he was too. His decision was an expression of a long-term distrust of mainstream or “allopathic” medicine. It did create a small stir at the time. Pregnant friends were uneasy: if the unvaccinated children did contract any of that unwholesome trio of infections, would they present a risk to their unborn children? They also travelled to countries with far shakier public health infrastructures than ours. In my more uncharitable moments I also carped about free-riding and population immunity: the chances of their unvaccinated children coming to harm being significantly reduced by the decisions of myriad others. I did not doubt that my friend was acting in good faith. His feelings for his children were no less substantial than mine. But try as I might I could not see the difference between us as a straight value clash. Values do not float free of evidence; they are informed by it. Seeking to realise our values we turn to the facts of the matter. And the facts, when it comes to the benefits and burdens of vaccination are incontrovertible. The nearest route to protecting your children from measles, mumps, and rubella is to vaccinate them. The world is more than the sum of our value judgments about it.

Given the importance of protecting the health of our children, and given that parents have rights to promote the interests of their children according to their own lights, how do we proceed where these interests conflict? Should parents ordinarily be compelled to vaccinate their children? We hear a lot about rights these days, less about duties. Prior to the rights of parents to make decisions on behalf of their children lies the duty to promote their interests. The right is an expression of the duty. Fail significantly enough to fulfil the duty and the right will fall away—no parents have the right, in extremis, to destroy their child. Where then to draw the line? Once again we need to turn to the facts. In the UK, population immunity has meant that the risks of not immunising your children are reduced and the small risks associated with vaccination hang slightly heavier in the balance – back again to the free-rider question. In these circumstances the case for compulsion – or at least persuasion—is not so strong. Some states disagree, placing significant burdens on parents who do not vaccinate their children, the burden, for example, of educating your children at home. In different circumstances the arguments in favour of a more coercive approach are stronger: consider the emergence of a lethal virus with a readily available vaccine. There is a limit to the amount of risk parents can adopt on behalf of their children.

I do not know whether or not my friend relented and vaccinated his children. I see his son from time to time at the rec or when I’m dropping my eldest at the youth club and thankfully he is a fine and healthy lad. But we come of a generation that has not had to witness the evils that once endemic infectious diseases can visit. And when I hear people extol the virtues of all things natural I cannot stop myself from saying that there is nothing as natural as plague and pestilence—we just happen to live in luxurious times.

Julian Sheather is ethics manager, BMA. The views he expresses in his blog posts are entirely his own.