Vaccination coverage against HBV in France is around 30% in the adult population. Treatment with anti-CD20 is associated with a risk of reactivation of hepatitis B or acute or fulminant hepatitis in first-infected patients. HBV vaccination is recommended as before any anti-CD20 treatment in unimmunized patients.

However, there is no recommendation on which vaccination regimen to choose in patients on immunosuppressants / corticosteroids or with inflammatory or autoimmune disease.

For patients who have a need for rapid immunosuppressive therapy, the use of a standard vaccination schedule (D0, M1, M6) would be responsible for a loss of chance vis-à-vis the underlying disease with a delay of more than 6 months to start treatment with anti-CD20. An accelerated regimen (D0, D7, D21 and M12) allows healthy adults to obtain very rapid vaccine protection between 77 and 90.8%. The accelerated regimen can also be considered on a case-by-case basis in those adults with neurological pathologies, systemic vasculitis or autoimmune disease and who need to receive anti-CD20 antibodies if the combination of injections over a short period is likely to promote immunization.

The advantage of the accelerated regimen is to obtain 4 weeks, after the third dose of vaccine, anti-HBs antibodies at a protective level (> 10 IU / L) in approximately 77 to 90.8% of patients and in the general population. The booster injection at 12 months is essential for long-term protection.

An accelerated regimen allows healthy adults to obtain vaccine protection very quickly. The accelerated regimen can also be considered on a case-by-case basis in those adults with neurological pathologies, systemic vasculitis or autoimmune disease requiring an anti-CD20 monoclonal antibody if the combination of injections over a short period is likely to promote immunization.

The aim of this pilot, interventional study is to evaluate the anti-HBV vaccine response measured by the level of anti-HBs antibodies greater than 10 IU / l after vaccination in patients to receive treatment with anti-CD20.

Evaluation of the specific anti-HBV vaccine response, measured by the level of anti-HBs antibodies greater than 10 IU / l at M2, M6 and M13 in patients having received a regimen accelerated by Engerix B 20 µg (D0, D7, J21), then recall 12 months later. Anti-CD20 drugs should be started at least 1 month after the first 3 injections for neurological pathologies and after the first 2 injections for vasculitis and autoimmune diseases (scheme linked to the underlying pathology with the need for rapid treatment with anti -CD20 in these pathologies).

Follow-up of 3 parallel cohorts of patients seronegative for hepatitis B virus (HBV):

• 1 cohort followed for multiple sclerosis or another inflammatory neurological disease (group 1)
• the cohort followed for systemic vasculitis (group 2)
• 1 cohort followed for an autoimmune disease (RA, Lupus, etc.) (group 3) to receive treatment with anti-CD20 (rituximab or ocrelizumab) and to be vaccinated against hepatitis B.

The patients will be followed for a period of 13 months after the start of the vaccination.

Inclusion Criteria:

• Patients over 18 years old
• Multiple sclerosis or other known neurological disease (group 1), systemic vasculitis (group 2) or autoimmune disease (group 3)
• Decision on treatment with anti-CD20 (rituximab or ocrelizumab)
• Free and informed consent, oral
• Negative hepatitis B serology.

Exclusion Criteria:

• Previous hepatitis B vaccination
• Major disability
• Pregnancy