I am getting really sick of the use of the term "denier." It's become cliched to a point where it become a euphemism intended to heard people into mental boxes and obscure rather than convey meaning.
I don't have all that much sympathy for people who don't follow the normal vaccination schedule for their kids. I think it's somewhat complex though. For example, some vaccines are more for public than private health. I think it's valid to be weirded out by a strong demand that kids go through a medical procedure for the good of humanity, rather than their own health.
On one hand I think the work being done by the Gates Foundation on wiping out Polio is incredible. On the other, how much pressure is reasonable to put on parents to vaccinate their children against an illness that poses less danger to them than meteors.
In any case, "denier" has become a term that almost always diminishes nuance and meaning rather than enhancing it. It ensures an us-and-them format to a topic. It also has a real nasty connotation (in my mind) to heresy. A heretic is a denier. In the wake of last week's attacks in Paris, it sounds even worse to me.
These people may be wrong or misguided. You might disagree with their assumptions, their conclusions or even their values. But, there is no reason or utility in this nastiness. There is less chance of convincing anyone with this language. And to those of us on the opposite side of the debate, it makes us dumber to allow such mental patterns to dominate our thinking.