The varicella-zoster virus is a herpes virus which causes a febrile disease with a vesicular rash during childhood. The virus persists in the human body for life (latent infection) and upon reactivation later in life may cause shingles, with increasing frequency at older ages.
A live attenuated vaccine against varicella - later also indicated to prevent zoster - was developed in 1974 by Takahashi and colleagues and licensed for universal immunization of healthy children in the United States in 1995 as well is in European countries.
It has proven extremely safe and side effects are unusual, mild, and less serious than complications of varicella. 85% of children are completely protected after 1 dose. For optimal effect, 2 doses are required. Childhood zoster was reduced by 78%.
It was demonstrated in 2005 that zoster can also be safely prevented in 50% of vaccinees over age 60 years using a vaccine dose 15 times higher than that used for prevention of varicella in children.
A new, adjuvanted subunit zoster vaccine was licensed in 2017 by the American FDA and in 2018 by EMA in Europe based on an efficacy of about 95% and an excellent safety profile.