Inclusion Criteria:  Age between 18-35 years old OR age ≥60 years old Written informed consent  Exclusion Criteria:  Known allergy to (components of) the influenza or herpes zoster vaccine Immunocompromised subjects and subjects with active malignancy within the last two years Previous herpes zoster vaccination in the last year Receipt of any vaccination 4 weeks prior to the start of the study or plans to receive any other vaccination in the first 2 months after inclusion Use of systemic immunomodulatory drugs:steroids, anti-inflammatory biological treatments (e.g. anti-cytokine monoclonal antibodies) Acute or active illness within two weeks prior to the start of the study Pregnant, breastfeeding or planning to become pregnant during the study period