The history of immunisation can be traced through two major narratives. The first is a story of profound benefit to global health, the other a complex tale of risk and uncertainty versus safety and public confidence. These narratives are forever intertwined, not least because as successful immunisation programmes lead to progressive reductions in disease risk, so the prospect of adverse vaccine-related events becomes a dominant public concern.

Anaphylaxis has long been recognised as a rare but serious complication of vaccination, but despite millions of infants and children receiving vaccine doses every year, data describing the incidence of anaphylaxis as an adverse event following immunisation (AEFI) are surprisingly sparse. Erlewyn-Lajeunesse et al's prospective survey of anaphylaxis as an AEFI, published in this issue, provides a valuable addition to the existing evidence concerning vaccination safety.1

Serious allergic reaction in childhood sits alongside meningitis in the public consciousness as a seemingly random, rapidly progressive and life-threatening event. Anaphylaxis as an AEFI is feared by health professionals for the same reasons, and because it follows an active health intervention administered to healthy children. Exaggerated fears of provoking anaphylaxis by giving combined measles, mumps and rubella (MMR) vaccine to children with egg allergy have taken a long time to dispel, with many paediatricians receiving referrals for in-hospital MMR immunisation long after the publication of evidence providing strong reassurance that this is largely (and perhaps entirely) unnecessary.2 In deciding how to manage very small risks of major complications, health professionals can find it difficult to …