This issue carries a paper from Burkina Faso on the non-specific effects of vaccination on survival in children (p1309).1 The study analyses mortality in a cohort of children as a function of their vaccination status. The authors conclude that vaccination with diphtheria, tetanus, and pertussis (DTP) vaccine as well as BCG is associated with better survival of children up to 2 years of age.” The paper should be viewed with caution and in context.

Non-specific effects of vaccination, beneficial or detrimental, have been discussed for about 15 years. Some vaccines have effects on non-target diseases—for example, BCG protects against leprosy.2 Some vaccines have rare adverse reactions—for example, myopericarditis following smallpox vaccine.3 High titre measles vaccines were evaluated in the 1980s and withdrawn because of a hint of unexpected mortality in vaccinated girls.4 This observation stemmed from work by Aaby et al and led to a series of publications linking morbidity and mortality patterns to vaccination in several populations, particularly in West Africa. BCG and standard titre measles vaccines were claimed to be more beneficial than could be explained by their effects on tuberculosis or measles alone.5 6 Associations found in one population were not …