Ordinarily, I would not consider a deviation from absolute scientific truth to be a problem in science fiction. But I am disturbed by the dangerous and incorrect implications in A. G. Carpenter's Futures story that vaccines weaken the human immune system, and that their effects are on a par with poisoning by lead or tobacco (Nature 506, 126; 2014).

Vaccines are safe, effective and rigorously tested (see, for example, Nature Immunol. 9, 1317; 2008). Ungrounded fears already prompt parents unnecessarily to opt out of vaccination programmes for their children, leading to entirely avoidable illnesses and diminishing herd immunity.

In my view, it is irresponsible to promote the idea that vaccines are bad for health — even fictitiously.