The Epstein–Barr virus is one of the nine known human herpesvirus types in the herpes family, and is one of the most common viruses in humans. EBV is a double-stranded DNA virus and is also called human herpesvirus 4. Epstein–Barr virus is the first identified oncogenic virus, or a virus that can cause cancer. EBV establishes permanent infection in humans. It causes infectious mononucleosis and is also tightly linked to many malignant diseases. Various vaccine formulations underwent testing in different animals or in humans. However, none of them were able to prevent EBV infection and no vaccine has been approved to date.
Infectious mononucleosis, is characterized by extreme fatigue, fever, sore throat, and swollen lymph nodes. From Wikipedia
