Any child that dies from measles is suffering from undernourishment, specifically fat soluble vitamins A and D, not a vaccine deficiency.
likewise any respiratory illness such as flu, muh-covid, etc are the result of lower beta-carotene intake - low Vit A and low Vit D levels (prob also asthma and seasonal allergies but this is much less studied).
Some are almost certainly illegals, but every media story I've seen has bee "Mennonite communities that tend to shun vaccination". Funny how nobody ever asks "well, where did it come from if everyone else is vaccinated?".
Also, I'm not sure we're actually seeing any more cases now than we have at any other point in the last 25 years. 200 cases/year is an insanely small number. But even if we are, who cares.
It's all propaganda to scare people into compliance.