I have spent much time addressing claims that the MMR vaccine is associated with Autism (it isn't). Study after study after study have shown that there is no causal link between the MMR vaccine and the incidence of autism. That is a dead issue.
However, the anti-vaccination movement has spilled over (and has been brewing, obviously, for a number of years) into seasonal flu and, more importantly, H1N1 vaccination myths.
I won't go into what herd immunity is or even the thimerosal arguments - I addressed them in an old blog posting (Jenny McCarthy is my hero).
Wired Magazine has recently published an article, "An Epidemic of Fear: How Panicked Parents Skipping Shots Endangers Us All" that is well worth the read. It is a lengthy article but explains the war on science, a little history of the anti-vax movement and addresses a great number of the myths that still surround vaccinations.
In the end, the Anti-Vax movement's greatest weapon? Lies. The misinformation might kill or harm you or someone you love.