Specific Cellular and Humoral Immune Responses to the Neoantigen S1 of SARS-CoV-2 in Patients with Primary and Secondary Immunodeficiency (preprint)

ABSTRACT

Patients with antibody deficiency disorders, such as common variable immunodeficiency (CVID), or secondary immunodeficiency (SIDs) to B-cell lymphoproliferative disorder (B-CLPD), are two vulnerable groups of developing severe or chronic form of coronavirus disease caused by SARS-CoV-2 (COVID-19). Data on adaptive immune responses against SARS-CoV-2 is well described in healthy donors, but still limited in patients with antibody deficiency of different cause. Herein, we analyzed Spike-specific IFN-γ and anti-Spike IgG antibody responses at 3 and 6 months after exposure to SARS-CoV-2 derived from vaccination and infection in two cohorts of immunodeficient patients (CVID vs. SID) compared to healthy controls (HC). Baseline cellular responses before vaccine administration were measured in 10 CVID patients. Adequate specific cellular responses was observed in 18 out of 20 (90%) CVID patients, in 14 out of 20 (70%) out of 20 SID patients and in 74 out of 81 (96%) HC. Specific IFN-γ response was significantly higher in HC respect to CVID (1,908.5 mUI/ml versus 1,694.1 mUI/ml; p = 0.005). Pre-vaccine anti-SARS-CoV-2 cellular responses were detectable in 4 out of 10 CVID patients, who had COVID-19 prior to vaccination, noticing an increase in cellular responses after vaccination (p < 0.001). Whereas all SID and HC mounted a specific humoral immune response, only 80% of CVID patients showed positive anti-SARS-CoV-2 IgG. The titer of anti-SARS-CoV-2 IgG was significantly lower in SID compared with HC (p = 0.040), without significant differences between CVID and HC (p = 0.123) and between CVID and SID (p = 0.683). High proportions of CVID and SID patients showed adequate specific cellular responses to S1 neoantigen, with divergence between cellular and humoral immune responses in CVID and SID patients. Our data might support the relevance of these immunological studies to determine the correlate of protection to severe disease and for deciding the need of additional boosters. Follow-up studies are required to evaluate the duration and variability of the immune response to COVID-19 vaccination or infection.