As a child, I had the measles, mumps, chicken pox, pneumonia and various other childhood illnesses. In those days, we did not get vaccinated for that stuff. I did get the polio vaccination via sugar cubes. So, I received my immunity by surviving the illnesses. Whether or not I still have the immunity, I guess an expert will tell. I have never had the flu as far as I can tell, but I also never get the flu vaccination. Maybe once I get it and (if) survive it, I might consider getting the flu shot in the future. I have been vaccinated for the Covid, but actually did it based on my spouse's medical condition. Even though I had the chicken pox, and I do not know whether the immunity would help dealing with shingles, I still got my shingles shot when I heard that a neighbor had a bad case of shingles. I have seen how it effects folks and how painful it is, so I was vaccinated.
Be careful about discussing "measles" or someone might get the idea of doing a "gain of function" study/experimentation on measles.
