The Epstein-Barr virus (EBV), also called Human herpesvirus 4 (HHV-4), is a virus of the herpes family (which includes Herpes simplex virus and Cytomegalovirus), and is one of the most common viruses in humans. Most people become infected with EBV, which is usually asymptomatic. It is named after Michael Epstein and Yvonne Barr, who discovered the virus in 1964 .
The genome size of the reference B95-8 laboratory strain of this virus is 172,281 nt *. Other laboratory and wild isolates vary somewhat in genome size.

Epstein-Barr Virus - Fact sheet from the Centers for Disease Control.