A press release issued by South Africa’s department of health contains the following revealing paragraph:
One striking feature of this latest outbreak is that while it has affected children of the poorer communities, it has also been concentrated among relatively well-off children, predominantly in the 15-19 year old age group. We believe that in both groups, the underlying cause has been failure by the parents or guardians to take children for immunization i.e. both the initial and follow-up doses.It seems likely that among the well-off children (and much less so among the poorer children, where other factors were likely involved) the cause is parents’ fears over vaccines causing autism. The source of these fears is the anti-vaccination movement (and their idiotic celebrity sponsors) that has spread unscientific claims that either the MMR vaccine causes autism or that thimerosal (until recently a common vaccine ingredient) causes autism. These claims have been disproved beyond reasonable doubt. Being more influenced by Britain than America, it's probable that the MMR claim is most relevant to South Africa, so I'll focus on that. The source of the MMR-autism worry was a deeply flawed, and possibly fraudulent, 1998 study by Andrew Wakefield and colleagues, that was merely a case series of 12 subjects (that is, a series of 12 anecdotes) that could not, in principle, determine whether there was a causal link. Moreover, Wakefield had undisclosed conflicts of interest (he received £50,000 in legal aid money from lawyers preparing a case against MMR – over the years he received over £434,000 from such cases). Wakefield is also currently under investigation by the UK's General Medical Council on charges of serious misconduct, and he might lose his license to practice.
Just because the original study was flawed does not mean, of course, that the there cannot be a link between vaccines and autism. But, as I said above, numerous subsequent studies have found no such link. In other words, there is no good reason at all to think vaccines cause autism. Note to parents: VACCINATE YOUR CHILDREN. Dammit.
(via The Lay Scientist)