> But somehow, in the US one unvaccinated child is a risk to a school full of vaccinated children? This doesn't make sense.You're misunderstanding who is at risk in this scenario. It is not the vaccinated who are at risk; it is the unvaccinated.
The unvaccinated are protected by the "wall" of immune people separating them from the sick. The fewer and farther between are the at-risk, the decreased likelihood of transmission.
You might say "but those people took that risk on their own"; but thats not the case for many people. i.e., Newborn infants, Individuals who are immunodeficient due to HIV/AIDS, lymphoma, leukemia, bone marrow cancer, an impaired spleen, chemotherapy, etc.[1].
Essentially, those who cannot become immune are only protected by herd immunity. And every additional non-immune person in that pool increases the risk to all the others. So everytime someone chooses to remain immune they are hurting that whole pool, some of whom cannot choose.
[1] https://en.wikipedia.org/wiki/Herd_immunity#Protection_of_th...