Mono Transmission: How Contagious Is Mononucleosis?

It is unlikely that you can catch mononucleosis from a friend who had it two months ago. This is because the incubation period for mono is typically 4 to 6 weeks. This means that a person can spread the infection before they even know that they have it. However, once a person has recovered from mono, they can no longer spread it to others.