Let's say a particular disease requires 80% of the population to be vaccinated to provide herd immunity (this percentage varies by disease). You are extremely u

Let's say a particular disease requires 80% of the population to be vaccinated to provide herd immunity (this percentage varies by disease). You are extremely unlikely to have 20% of the population have AIDS or otherwise be so immuno-compromised so that they cannot get a vaccine, so everyone is safe. The anti-vaxxers come along and free-ride, and for 10+ years, they think the are brilliant -- their kids do not get these mythologized diseases! But one day, enough morons start thinking that, that you reach a tipping point, and only 75% are vaccinated. All of a sudden, an outbreak occurs, putting all the immuno-compromised at risk, as well as the other 20%+ children of anti-vaxxers. Many kids die or become very sick. Suddenly, the anti-vaxxers realize they were playing with fire, putting children at risk. What don't you get about this?