Brief Report: Humoral and cellular immune responses to SARS‐CoV‐2 infection and vaccination in B cell depleted autoimmune patients

Abstract

Abstract Objective B cell depletion is an established therapeutic principle in a wide range of autoimmune disease. However, B cells are also critical for inducing protective immunity after infection and vaccination. We therefore assessed humoral and cellular immune responses after infection with or vaccination against severe acute respiratory syndrome coronavirus ‐2 (SARS‐CoV‐2) in B cell depleted patients and B cell competent healthy controls. Methods Antibody (ELISA) and T cell (IFNγ ELISPOT) responses against the SARS‐CoV‐2 spike S1 and nucleocapsid proteins were assessed in a limited number of infected (N=6) and vaccinated (N=8) B cell depleted autoimmune patients as well as infected (N=30) and vaccinated (N=30) healthy controls. Results As expected, B and T cell responses to the nucleocapsid were observed only after infection, while respective responses to spike S1 were found both after infection and vaccination. A SARS‐CoV‐2 antibody response was observed in all vaccinated controls (30/30, 100%) but in none (0/8) of the vaccinated B‐cell‐depleted patients. In contrast, after SARS‐CoV‐2 infection, both B‐cell‐depleted patients (spike S: 5/6, 83%; nucleocapsid 3/6, 50%) and healthy controls (spike S: 28/30, 94%; nucleocapsid 28/30, 93%) developed antibodies. T cell responses against the spike S1 and nucleocapsid proteins were found in both infected and vaccinated B cell depleted subjects and in the controls. Conclusion These data show that B cell depletion completely blocks humoral but not T cell SARS‐CoV‐2 vaccination response. Furthermore, limited humoral immune responses are found in B cell depleted patients after SARS‐CoV‐2 infection.