The real story behind the new Institute of Medicine report on vaccine-related adverse events isn’t — as many stories have highlighted — that evidence fails once again to support the MMR-autism link. Everyone with a grain of sense has understood this for years; the IOM itself published one of the definitive reports on vaccines and autism seven years ago, and the weight of evidence against the association has only grown heavier since then.
Rather, the most significant note to be made is that recent additions to the vaccination panic spectrum — including concerns that vaccines can cause asthma, Type I diabetes, and Bell’s palsy — are equally lacking in epidemiological and mechanistic support. Where the evidence does favor a causal link between vaccines and specific adversities, the events themselves are generally rare and transient. The more serious risks are borne by children with compromised immune systems or with underlying metabolic disorders (like Dravet syndrome); however, in these cases, it’s worth pointing out that the adverse events in question are almost always milder versions of the very complications that would result from exposure to the actual diseases. And with vaccination rates on a depressingly downward course in states like California — where “personal belief” exemptions allow parents to eschew entirely reasonable public health measures — vulnerable populations will be at much greater risk from the circulation of measles and pertussis than from the MMR and DTaP vaccines. But since Americans are generally inept at assessing risk, the case for tightening those exemptions is not likely to bear many results until we see some pretty massive body counts. Hooray!
Predictably, Orac has the best rundown on the report.