evidence: One myth that won't seem to go away is that the DTP vaccine causes sudden infant death syndrome (SIDS). This belief came about because a moderate proportion of children who die of SIDS have recently been vaccinated with DTP; on the surface, this seems to point toward a causal connection. This logic is faulty, however; you might as well say that eating bread causes car crashes, since most drivers who crash their cars could probably be shown to have eaten bread within the past 24 hours. If you consider that most SIDS deaths occur during the age range when three shots of DTP are given, you would expect DTP shots to precede a fair number of SIDS deaths simply by chance. In fact, when a number of well-controlled studies were conducted during the 1980s, the investigators found, nearly unanimously, that the number of SIDS deaths temporally associated with DTP vaccination was within the range expected to occur by chance. In other words, the SIDS deaths would have occurred even if no vaccinations had been given. In fact, in several of the studies, children who had recently received a DTP shot were less likely to get SIDS. The Institute of Medicine reported, "all controlled studies that have compared immunized versus non-immunized children have found either no association . . . or a decreased risk . . . of SIDS among immunized children," and concluded, "the evidence does not indicate a causal relation between [DTP] vaccine and SIDS."