Two months ago I hooked up with a girl who said she had a cold (let's ignore the stupidity on my part there). The next day she said she went to the doctor and told me she had mono. Naturally, I prepared for the worst because I heard that mono has a 5-6 week incubation period. About 6 weeks later, I was still feeling fine and went to the doctor to get tested. Mono tests came back negative. How is it possible that I didn't get it?

Is mono always inevitable or is it possible to beat it with a solid immune system and not become infected even if one is directly exposed?

  • 2
    It's quite possible to not catch any disease from contact with someone who has it. There are many, many factors affecting whether you become infected or not, so many so that it's impossible to predict. Your immune system no doubt played a role, but I wouldn't count on that next time.
    – Carey Gregory
    Commented Dec 7, 2016 at 3:17

1 Answer 1


Mononucleosis is usually caused by Epstein-Barr virus, but other viruses such as cytomegalovirus can cause it as well [1]. EBV is a really common infection, and it's very likely that you've been exposed at an early age without developing serious symptoms[2]. If that's the case, you wouldn't be infected by a person with active mononucleosis.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.