Inclusion Criteria:  Age greater than or equal to 18 years Patients eligible for BNT162b2 vaccination  Immunocompromised patients according to one of the following criteria:  Patients with autoimmune or autoinflammatory diseases treated  For at least three months Having received at least 0.1 mg / kg / day of prednisone (or equivalent) for at least three months Currently receiving at least 5 mg / day of prednisone in combination with an immunosuppressant (methotrexate, cyclosporine, mycophenolate mofetil, rapamycin, azathioprine, cyclophosphamide) or biotherapy (anti-B cells (rituximab and others) anti-TNF, IL- 1, IL-6R, IL-12/23, IL-17, or B7 (CTLA4-Ig)) or a kinase inhibitor (Janus, Tyrosine)) HIV-infected patients with a CD4 count <500 / mm3 and a viral load <50 copies / ml on stable antiretroviral therapy for at least 3 months Patients with multiple sclerosis treated with a disease-modifying drug for at least 3 months at a stable dose (teriflunomide, dimethyl-fumarate, fingolimod, ocrelizumab, rituximab, natalizumab)  Patients with solid tumors or cancers:  Patients who have received active cancer treatment other than chemotherapy (targeted therapy, radiotherapy, surgery, hormone therapy) in the previous month Patients who have received active cancer treatment with chemotherapy (alone or in combination with immunotherapy, radiotherapy or targeted therapy) in the previous month Patients who have received active oncology treatment with one or more immunotherapy (s) in combination with anti-PD1, anti-PD-L1, anti-CTLA4 antibodies without chemotherapy in the previous month. Solid organ transplant patients for more than 3 months who have not received a depleting T agent in the induction protocol, and for> 6 months otherwise Life expectancy of more than 3 months Having been informed about the study and having given their written and informed consent Beneficiaries or beneficiaries of a social security scheme  Exclusion Criteria:  Patients who may be included in more than one of the sub-cohorts Other vaccination received in the 15 days preceding recruitment or planned in the month following the second vaccine injection Known or suspected allergy to one of the components of the vaccine Severe reaction after previous administration of any influenza vaccine (multiple sclerosis, Guillain-Barré syndrome) Contact subjects of a patient with an undetected documented SARS-CoV-2 infection Evocative signs of COVID-19 History of documented SARS-CoV-2 infection of less than 3 months (RT-PCR, Lamp PCR, antigen test) Last outbreak of the disease less than 3 months old for patients with Multiple Sclerosis; less than a month old for patients with autoimmune or autoinflammatory diseases For patients with HIV, transient viremia (blip) less than 3 months old Intercurrent infection For organ transplants, episode of cellular or humoral rejection during the 3 months preceding inclusion Healthy volunteers Pregnancy less than 13 weeks old according to the declaration of pregnancy Refusal of participation by the patient Patients subject to legal protection measures