Possibly, but you can't improve your immune system if you are dead. For example, if you get infected with the Epstein–Barr virus at an older age [0], the probab

Possibly, but you can't improve your immune system if you are dead. For example, if you get infected with the Epstein–Barr virus at an older age [0], the probability of a severe outcome including death are increased. The Epstein–Barr virus, probably more so after these later and possibly more severe outcomes, probably causes many cases of multiple sclerosis. Kissing can spread the Epstein–Barr virus (EBV). Many herpesvirus, including Epstein–Barr, can cause superinfection, but if you were infected with EBV and HSV1, a EBV or HSV1 superinfection would probably be less likely to cause severe outcomes assuming you are HIV negative and your immune system is otherwise competent. If you plan on reproducing without the use of a turkey baster (or pipettes and sperm washing if you are a woman), it's probably not worth avoiding infection though, because you or your partner getting infected during pregnancy is way, way worse. [0]: after six months is already not great, but as a teenager it's pretty bad and it just gets worse from there.