take a population of children over one with equal health status
the vaccine is supposed to be 95 pc effective
so in a hundred children, five will be non immune
imagine a further 5pc of that hundred fail to vaccinate
so 10pc total will probably catch it as it's so contagious
so far you have the interests of five vaccinated non immune against five non vaccinated non immune children
a fair balance, no? why should the interests of those five vaccinated supercede the interests of the five non-vaccinated, and the five non vaccinated take a risk to protect the five vaccinated? better still, why not blame the manufacturer for selling them a product that doesn't work?
Now imagine that 10pc fail to vaccinate. The balance changes. 15pc of children will probably catch measles. This time five of them are vaccinated, ten of them are not. Now you are asking ten children to take a risk to protect five children.
The numbers of non vaccinated go up, and it becomes less and less viable to propose that the larger number takes a risk to protect the smaller number.
In all this time, the number of vulnerable vaccinated children remains the same. Five. Ninety five per cent of vaccinated children will not catch measles.
It is rather difficult to justify say, 20 children taking a unknown risk to protect 5 children from an unknown risk.
Unless of course you ARE saying that exposure to measles virus reduces vaccine immunity, and endangers a larger part of the vaccinated population.