The varicella zoster virus causes two infections: varicella, also known as chickenpox occurring mostly in childhood, and herpes zoster, also known as shingles affecting mainly older people. Varicella usually occurs in children under ten years of age. It is generally a mild infection and in the UK vaccination is not offered as part of the routine immunisation programme. However, adults who develop varicella are at risk of developing complications and the infection is likely to be more severe. Serious complications are a particular risk for pregnant women, unborn children, neonates and those who are immunocompromised. Nurses whose work brings them into contact with those at risk have a vital role in providing information about the importance of avoiding varicella. After the acute infection, the varicella zoster virus gains access to the ganglia in the sensory nervous system where it can remain dormant for years. Reactivation results in herpes zoster, a common and unpleasant illness. A vaccine for herpes zoster was introduced for people aged 70-79 in the UK in September 2013.