>>11777634It makes sense, if you think about it. If you expose yourself to a lot of pathogens early on, you adaptive immune system will have memory of a shit ton of pathogens. As an adult, when you get infected by them again, you won't even have any symptoms.
As a lot of pathogens are related, you can get cross-immunity to one because you were exposed to another. It really makes sense if you think about it.
The only problem is pathogens that don't generate long lasting immunity, like the flu.
