VZV PCR Sampling Validation Study

Inclusion Criteria: * Clinically diagnosed with herpes zoster by the investigator including the presence of a typical herpes zoster rash. * A male or female aged 50 years or older at the time of the subject's enrolment. * Written informed consent obtained from the subject. * Subjects who the investigator believes that they can and will comply with the requirements of the protocol should be enrolled in the study. Exclusion Criteria: * Any malignancy for which the subject is receiving active treatment, or any haematological malignancy. * Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs within three months prior to the first vaccination, including corticosteroids, except inhaled and topical steroids are allowed. * Concurrently participating in another clinical study, at any time during the study period, in which the subject has been or will be exposed to an investigational or a non-investigational product (pharmaceutical product or device). * Previous vaccination against herpes zoster. * Confirmed or suspected immunosuppression, based on medical history or physical examination (no laboratory testing required). * A family history of congenital or hereditary immunodeficiency. * History of or chronic alcohol or drug abuse.