Varicella-zoster virus (VZV), herpes simplex virus one (HSV-1) and herpes simplex virus two (HSV-2) represent three out of the eight known human herpesviruses and belong to the subfamily of α-herpesviruses. These viruses are present worldwide and humans are their sole host and reservoir. After the primary infection, these viruses persist in the body throughout life. The period of latency may be interrupted by reactivation of infection due to various factors. Each virus can induce a wide spectrum of diseases. The primary infection is typical for children and otherwise healthy individuals are often asymptomatic. It is mainly immunocompromised patients who are at risk of developing severe disease or complications when infected by these viruses. However, even in otherwise healthy individuals an infection by a-herpesviruses can run a severe course and lead to death.