If you had it once, it's very unlikely you will get it again.

It's also very unlikely that you were vaccinated against it, the vaccine did not even exist when I was a child. It's only been approved for about 10 years and is still not anywhere near as commonly used as others.

I can't believe anyone would take their sick child out in to public, I would have said something but that's just me. I had them when I was 7 and barely went outside of the house and wan't allowed to touch anyone or anything past my front door.