“Measles has not always had a vaccine.”
I obtained measles immunity the old fashioned way.
I went to a measles party when I was 5. Parents would deliberately infect their children, all of them, as soon as they could. And as recommended by darn near every family doctor in the country.
Before about the age of 8, measles kills or permanently damages about 1/10,000.
As an adult you’re lucky to live through it.
And those parents were stupid. They put their children at risk for death or severe long term disability
Fortunately my parents were medical professionals. They didn’t do that. Yes I caught measles from someone who had it. I have never been as sick as I was then. I’ve had not H1N1 and Hong Kong Flu. They didn’t come close