Aside from allergies or certain medical conditions, there really isn’t a logical reason not to vaccinate. Parents today don’t have to fear the same infectious disease for our children that our grandparents did. They’ve mostly all been managed or eliminated by vaccination. Of course, nothing is ever 100% safe, but serious adverse reactions to vaccines are incredibly rare. In spite of the minimal risks, vaccination is still worth it to prevent all of those manageable diseases from roaring back with completely devastating effects.
The worst reason to forego vaccination is because of an ill-founded belief that vaccines contribute to the cause or exacerbation of autism. There is absolutely no scientific proof to support that claim, though some people just can’t let it go. Trying to drive home the point that vaccines don’t contribute to autism can become exhausting, because there’s really nothing to debate. Scientists can’t prove a negative; they can only show study after study that fails to show a link. There’s really only so many ways to say “no, that’s not true” without going crazy.
In Penn & Teller: Bullshit! they explore the efficacy of vaccinations and the anti-vaccination movement. During the intro, Penn sums up the entire issue in a way that I couldn’t put better myself: “Even if vaccination did cause autism, which it fucking doesn’t, anti-vaccination would still be bullshit!”