Herpesvirus. Coloured transmission electron micrograph (TEM) of a herpesvirus particle (virion). The herpesvirus group includes the viruses that cause chickenpox, shingles, genital herpes and cold sores. The protein coat of the virus, the capsid (red/yellow), encloses the genetic material (not seen). The capsid is surrounded by an irregular lipoprotein envelope (orange) with protruding viral proteins (green). Herpesviruses cause vesicular eruptions after which they may become dormant in the nervous system, becoming active again at a later date. Magnification unknown.