This is not a migration issue. It's an epidemiology issue. If enough members of the community are vaccinated, then an infectious disease like measles is not likely to spread. But there's a magic number in that: if not enough people are vaccinated, then the disease will spread.
I confess about 10 years ago I was very concerned about the link between the measles-mumps-rubella (MMR) vaccination and autism, such that much youngest daughter (who was experiencing speech delays at the time) was not vaccinated.
Turns out that I may as well have blamed Jupiter sitting low in the constellation of Virgo. The kids who "contracted" autism were suffering from a form of genetic disfunction whereby they would have regressed at a certain age anyway and exhibited autism-like behaviour. Many poor parents believe improperly that they contributed to their child's disability by getting them immunised: turns out it would have just happened anyway. The shot happens to occur in early childhood right when the disability manifests, creating the impression of a link.
There is a great documentary on this which explains the flawed first study, since retracted by the author, giving rise to this concern, and explains in lay terms what it is all about. I remember vividly seeing the look on one mother's face when she found out that her son's disability was not linked to the immunisation shot: intense release from guilt. He was just always going to be like that.
Last edited by First Amongst Daves; 2015-01-31 9:15 PM.
