Yellow Fever Vaccination Under Low Dose Methotrexate Therapy

Inclusion Criteria: * Informed Consent as documented by signature * Indication for yellow fever vaccination according to Swiss FOPH recommendations * Individuals under low dose MTX (≤20mg/week) therapy or healthy individuals * Male and Female travelers ≥18 years to \<60 years of age Exclusion Criteria: * Contraindications on ethical grounds * Women who are pregnant or breast feeding * Contraindication against yellow fever vaccination (e.g. hypersensitivity against vaccine ingredient) * Current treatment with other immunosuppressive agent apart from low dose methotrexate * Alemtuzumab or rituximab in the last year * TNF-blocking therapy in past three months * Immunocompromising condition in healthy control * Other immunocompromising condition than MTX treatment itself and the underlying disease in patients under MTX * Previous yellow fever vaccination * No indication for yellow fever vaccination according to Swiss travel vaccination recommendations * Known or suspected non-compliance, drug or alcohol abuse * Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc. of the participant