Measles can cause immune amnesia [1], which I find fascinating, and maybe somewhat obvious: our immune system has limited/fragile "memory".

[1] https://asm.org/articles/2019/may/measles-and-immune-amnesia

Apparently there is no known limit, so we could vaccinate for everything, repeatedly, without risking forgetting. Unlike getting the illness or antibiotic use, where there is limits and fragility as a possible result