TPP grew up when measles and polio were real threats. Kids died of measles too. Every one of my grade school classrooms had at least one student who had some form of paralysis from polio, so when the Salk vaccine became available parents wasted no time in getting their kids vaccinated. Polio has basically disappeared and the measles was almost eradicated in the USA 15 years ago and hasn't been a serious health problem for at least twice as long. This means that living within a well vaccinated herd the risk of these diseases seems very low, very distant, so avoiding vaccinations does not seem to place you at any risk. The recent measles out break shows how wrong that is in our global community where it is pretty easy to get to places where measles still exists. Then when the vector returns home, and visits some high traffic public place, you get an out-break of measles. In the safety of our herd, other risks are perceived to be greater like the discredited association of vaccinations and autism. This is a case of coincidence - the onset of autism often appears at about the same age as childhood immunizations and people naturally sought to find cause and effect relationships. This is an easy error in judgement to make, the result of only counting hits and not the way more numerous misses. Humans are quite bad at assessing risk; people fearful of flying think nothing of driving their cars although the latter is a far greater risk. In spite of the actual data, people see driving as a lower risk because they are in control. TPP gets parents terrified of letting their college age students take rain forest field trips because of the "dangers", but yours truly is much more worried about them the one night they spend in a city. But now the situation is becoming dire as the herd immunity has fallen below a safe level especially for something as easily vectored as measles. Now the decision to avoid vaccination for your children is no longer personal and no longer low risk; it affects the general public and your kids are at greater risk especially if they travel. This is why states used to require proof of vaccination before you could attend public schools; people make poor decisions that affect others. A good case can be made for not allowing unvaccinated people to leave the country, not because they are at greater risk catching a disease, which they are, but because they become vectors reintroducing an eradicated disease.