From an individual utility standpoint, suppose I am in a place where everyone else is vaccinated. The chance of me personally getting measles is 1 in a billion. Doesn’t this mean that the marginal negative risks of taking the vaccine exceed the *marginal *risks of not getting vaccinated?
Let’s say the negative reaction to the vaccine is 100 times less bad than the adverse effects of getting measles. And there’s a 1 in a million chance of having a bad vaccine reaction. Then, it’s simple math :
1 * x * (1/a million) > 100 * x * (1/a billion), where x is some “unit” of bad healthiness.
I suspect that’s why certain people want to skip the vaccine. Living in the USA in sheltered, well off areas, they have never actually seen or heard of anyone getting the diseases these vaccines are supposed to prevent. But the vaccine does have negative effects : the shots hurt, the area is sore, I have gotten flu like symptoms and been sick for days after, and I suspect I am not a 1 in a million individual. I personally have all my shots and then some, but I can see why people want to skip them.
The problem here is that skipping the vaccine is better for the individual in the same way that draft dodging or running away in combat is better for the individual. If significant fractions of the population do these things, though, it can be catastrophic for society.
So there’s no help for it. “For the good of the many”, skipping vaccinations has to carry significant penalties. Perhaps it could be a misdemeanor offense carrying jailtime, and oh by the way you can’t be held in jail without your shots or something…
Basically, the way you’ve phrased it, vaccination is the prisoner’s dilemma writ large. One problem with this analysis, though, is that vaccinations don’t always “take”; about 1% of the time, they don’t confer an immunity for whatever reason. This raises your chance of getting measles considerably if you’re unvaccinated.
Not *too *significant. Just more than the unpleasantness associated with getting the shot (minus the expected value of the shot, which as you said is pretty small as long as herd immunity is in effect).
Not getting a public school education is way more expensive than the minor side effects of the vaccine, so that’s a reasonable approach. I don’t think jail time is necessary.
Obviously this only applies to people making a rationally self-interested calculation. For parents that falsely believe that vaccines cause autism, the loss of a public education may actually not be as bad as (their belief in) the risk of autism. These people are obviously a greater danger.
“Everyone” must include, “Everyone in other countries”. Because the measles vaccine is 95% effective, you could even come down with the disease due to 2nd or even 3rd hand exposure to an unvaccinated foreign visitor. Sure the odds are low, but the OP is assuming 1 in 1 billion chances. The best you can do is probably closer to 1/100 million or maybe higher.
Also, the fact that some people legitimately cannot get vaccinated for medical reasons substantially raises the risk of contracting a disease, and makes it in everyone’s interest who can get vaccinated to get vaccinated.