Herpes zoster by reactivated vaccine varicella zoster virus in a healthy child

Varicella can be prevented by vaccination using the live-attenuated Oka vaccine strain of varicella zoster virus (VZV). Only mild breakthrough disease has been reported in seronegative vaccinees when exposed to the wild-type virus. The latent varicella vaccine virus has rarely caused herpes zoster in childhood and adolescence. We report a healthy 2-year-old girl who developed an impressive herpes zoster infection 16 months after vaccination, localised in three cervical dermatoma. As causative virus, VZV vaccine strain was identified by polymerase chain reaction and analysis of restriction fragment length polymorphisms of the amplified products. Conclusion: vaccine varicella zoster virus can occasionally reactivate in healthy children and present as herpes zoster. Virus characterisation is necessary to identify the strain and provide information on the incidence of occurrence.