In addition to a generally miserable illness, measles can cause complications: 1 in 5 unvaccinated people with measles in the US end up hospitalized. About 1 in 10 develop ear infections and/or diarrhea, and 1 in 20 develop pneumonia. Between 1 to 3 in 1,000 die of the infection. In rare cases, it can cause a fatal disease of the central nervous system called Subacute sclerosing panencephalitis, which typically develops 7 to 10 years after an infection. Measles can also devastate immune responses to other infections (immune amnesia), making people who recover from the illness vulnerable to other infectious diseases.

Man, if only there were a near instantaneous way to prevent any of that from happening.