Best for all of the population to know lol. Strong and healthy boundaries and the ability to tell a known psychopath to fuck off goes a long ways

I took care of someone once with cat scratch fever. Her cat got her maybe eight hour prior and she was a gnats ass hair away from losing her finger by the time she got to us. I do not recall if they lanced it or not but she got a shit load of IV antibiotics and was well shortly after, finger intact

I absolutely would still know the signs and symptoms. Medicine is never perfect. Vaccines significantly lower the risk of infectious disease but its never zero. In the Philippines, I was exposed to measles a couple times without realizing until after. I got my MMR when I was young. Never showed a symptom. But still, always good to be careful.