Vaccination: dangerous myths and erosion of trust in scientific authority

Most of us are familiar with the controversy over childhood vaccinations, MMR in particular, and a perceived link with autism, but how many continued following the story to learn about the rigorous scientific studies that subsequently examined this and found no increased risk from vaccination?

In my opinion there are two messages here: one is that controversy (or even better, conspiracy) attracts more attention than steady-as-she-goes type stories; but the second is that we should also recognise that science scrutinises all of its own claims and is willing to change the accepted wisdom based on this scrutiny. So, if it had been discovered that there was a causative link between vaccination and MMR, rather than cover that up, scientists (at least, the reputable ones) would have set to work on producing an alternative.

But this story about the mistrust of the scientific establishment is more than just a curious event in social history, it is a dangerous myth. As fewer people uptake the vaccines, the diseases rise in frequency. Measles is a serious disease that can result in long term consequences in some cases or even death. When enough people take the vaccine (about 90% of the population) the community as a whole is protected because there isn't enough "space" for the virus to live in, so that it effectively can't survive at all. However, when vaccine uptake is low, then people who were never vaccinated may get sick, but also other vulnerable people in the community such as babies that are too young to receive the vaccine yet, children who didn't mount an immune response to the vaccine (i.e., in the small number who receive the vaccine but where it is ineffective) and people who are otherwise sick or immunocompromised.  So, the decision of a few not to take the vaccine affects many other people in the community.

So what's the problem? Why do some people mistrust scientists yet follow carefully (even religiously) the advice of crackpot conspiracy theorists? There's an interesting article about this in the journal PLos Biology : A Broken Trust: Lessons from the Vaccine-Austism Wars which includes a discussion on how those who are simply communicating the message that the scientific analysis found no connection become villified and sometimes threatened with violence.

Is that a bit like killing a [n abortion] doctor because you value life so highly?