Responses to COVID19 Vaccination in Patients With a Treatment History of Rituximab.

Registry Study for COVID19 Vaccination Efficacy in Patients With a Treatment History of Rituximab.

Patients with treatment history of rituximab since 01.01.2019 and immunocompetent volunteers will be contacted to give a blood sample after their COVID19 vaccination, and in a subset also before vaccination. Immune responses of antibodies and SARS-CoV2-specific T-cells to the vaccination will be quantified and the rituximab effect on COVID19 vaccine-induced immune responses is analyzed.

Inclusion Criteria:

1. Patients who were treated with anti-CD20 treatment since 01.01.2010
2. Patients who received a COVID19 vaccination (completion of all required doses) until target date (initial target: 30.05.21, but can be delayed to 30.06.21, 30.07.21 or 30.08.21 in case of insufficient enrollment)
3. Volunteers without a history of anti-CD20 treatment exposure
4. All: written informed consent.

Exclusion Criteria:

Exclusion criteria for patients (any of the following)

1. Patients aged 18 years and younger at time of study enrollment and/or
2. Pregnant or lactating women at time of study enrollment and/or
3. Patients who do not provide written informed consent and/or
4. Patients who have previously had a COVID19 infection (self-reported COVID19 disease, positive PCR or serology)
5. Patients who are in a dependency relationship with the study personnel (hierarchical, social)

Exclusion criteria for volunteers (any of the following)

1. Volunteers aged 18 years and younger at time of study enrollment and/or
2. Pregnant or lactating women at time of study enrollment and/or
3. Volunteers who do not provide informed consent and/or
4. Volunteers who suffer from an active autoimmune disease, active cancer, immunosuppressive therapy, history of anti-CD20 treatment and/or
5. Volunteers who have previously had a COVID19 infection (self-reported COVID19 disease, positive PCR or serology)
6. Volunteers who did not complete their COVID19 vaccination
7. Volunteers who are in a dependency relationship with the study personnel (hierarchical, social)