Let's see here. Widespread diseases popping up, more rampant then 50 yrs in USA? Well let's remember, those individuals coming across the border in the Southern US, are poor people, who have little education, and their government never pushed preventive shots for measles, chicken pox, etc. They are in every city and town in the US. No Covid vaccines, no chicken pox, no polio, no measles vaccine. Majority of individuals mistrust the doctor's, they are afraid they will be deported, or their kids taken away. Some could careless about their own health. Fear and ignorance, and those with "Who cares" attitude.
Not only the citizens (people who were born and raised in the US), some due to their beliefs won't allow vaccinations for their kids. Others are selfish, ignorant, and or they made not have the time to get off work to take their infant or older kids to doctor to get shots. Some schools its mandatory to have vaccinations or else your child does not go to school. Other schools don't care.
I know and I have records, that I got shots, not just as a child but as an adult. One day who knows, because the scene of this sick world can change over night. I know there is a rise again of measles in USA. Its contain for but we just never know when the next ones explode will be.
To this day, if I visit someone of our friends in hospital or a nursing home, or urgent care with si k friend, I wear a face mask and I bring hand sanitizer. Mask not just for Covid, but the rise. In diseases that were once wiped out but now surfacing in cities n towns in USA.