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 Concenring 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 Concenring cases: Patient whose life expectancy related to B-NHL is less than 6 months, History of allogeneic hematopoietic stem cell transplantation