Response of Immune System to Flu Vaccination in PHTS

Inclusion Criteria: * Must be diagnosed with PHTS based on genetic testing * Must be a Radboudumc patient * Must be 18 years or older * Must be mentally competent * Must have provided written informed consent to participate in the study * Must be able to adhere to visit schedule and available to complete the study Exclusion Criteria: * • Known history of significant medical disorder, which in the investigator's judgment might confound the results of the study or pose additional risk to the subject by participation in the study * Known hypersensitivity to previous influenza vaccinations (Anaphylaxis) * Must not be allergic to chicken eggwhite * Pregnancy at start of study * Immunocompromised patients and those receiving concomitant immunosuppressive therapy or other immune modulating drugs including chronic steroid treatment. * Bleeding disorders including haemophilia and thrombocytopenia or treatment with anticoagulants(Due to risk of intramuscular hematoma after injection) * Must not have received vaccination with attenuated pathogens in the 4 weeks leading up to study. (Measles, mumps, rubella, yellow fever, rotavirus, BCG, typhoid)