Given the evolution of Covid 19, patient inclusions became very difficult or even non-existent in all participating centers over time

The specific immune response to SARS-CoV-2 includes a humoral response - specific IgM appearing 5 days after the onset of symptoms while IgG appears after 14 days - and a T lymphocyte component, with specific activated CD8 and CD4 T lymphocytes.

Mortality from infection varies greatly depending on the age of the affected subjects and their comorbidities including a history of cancer. Among these cancers, a history of malignant hemopathy in the 5 years preceding the onset of Covid-19 increases the risk of death by a factor of 3. Among them, lymphoid hemopathies induce hypogammaglobulinemia and / or lymphopenia. These factors combined with chemotherapy and immunotherapy treatments promote the development of infections in affected individuals. Among these, are the anti-CD20 monoclonal antibodies, widely prescribed for treating B-cell non-Hodgkin lymphomas (B-NHL). They induce a deep and lasting B-cell lymphopenia, which can promote infections. They reduce the production of antibodies and the constitution of memory responses to a new pathogen or to a vaccination. In addition, B lymphocytes likely have a key immunomodulatory role in the control of viral infections.

A retrospective study in 89 patients with lymphoma and Covid-19 were conducted after the first phase of the epidemic in different centers in the Île-de-France and eastern France regions. With a 6-month follow-up, a pejorative prognostic impact of anti-CD20 monoclonal antibody treatment on Covid-19-related mortality were showed.

Vaccination of these at-risk patients is therefore essential. A growing concern is how patients with B-NHL who have been vaccinated with a SARS-CoV-2 mRNA vaccine are protected against infection, depending on whether or not they have received anti-CD20 monoclonal drugs and / or chemotherapy.

Knowing the medium-term immunological evolution after vaccination against SARS-CoV-2 in patients with B-cell NHL is necessary in order to be able to adapt the therapeutic and vaccine recommendations.

The main objective of this study is to determine how recent treatment (in the year before vaccination) with anti-CD20 monoclonal antibody modifies the immune response after vaccination against SARS-CoV-2 in adults with B-NHL compared to patients who have not recently been exposed to this immunotherapy.

Inclusion Criteria:

• Adult aged at least 18 years old

  • Having received (at least) two injections of anti-SARS-CoV-2 messenger RNA vaccine (Pfizer and / or Moderna)
  • Affiliated to social security
  • consenting to the study
  • Concerning cases only: Be or have been affected by B-NHL in remission, active surveillance or during first-line or second-line treatment, regardless of this treatment

Exclusion Criteria:

Patient less than 18 years old

• Patient with protective measure (curatorship, guardianship, safeguard of justice, deprived of liberty, in an emergency situation)
• Patient unable to express their consent
• Pregnant or breastfeeding woman
• Patient refusing to participate
• Concerning cases: Patient whose life expectancy related to B-NHL is less than 6 months, History of allogeneic hematopoietic stem cell transplantation, Patient with CART cells treatment