Immunogenicity and safety of a recombinant spike protein COVID vaccine in patients with inflammatory bowel disease and transplant recipient

INTRODUCTION: Immunosuppressed individuals are at increased risk of coronavirus disease (COVID-19). Although mRNA vaccines have shown efficacy in these populations, data on protein-based vaccines remain limited. We evaluated the immunogenicity and safety of Novavax COVID-19 vaccine (NVX-CoV2601) in immunosuppressed patients. METHODS: This single-center, prospective ARMOR study included adults with inflammatory bowel disease (IBD) or solid organ transplant recipients receiving immunosuppressive therapy who had received ≥3 prior COVID-19 vaccine doses. Participants received one NVX-CoV2601 booster with follow-up at one and six months. The primary outcome was change in humoral immunogenicity from baseline to one month post-vaccination. RESULTS: Twenty-one immunosuppressed patients (18 IBD, 3 solid organ transplant recipients) were enrolled and compared with 57 age/sex-matched healthy controls. In ARMOR participants, anti-spike IgG GMT increased significantly post-immunization (22,969 to 66,639 EU/mL; 2.9-fold increase, p = 0.001). Healthy controls increased from 54,812 to 129,813 EU/mL (2.4-fold increase; p < 0.001). After baseline adjustment, no significant difference existed between groups at day 28. At 6 months, antibodies waned faster in immunosuppressed subjects. NVX-CoV2601 was well tolerated without IBD flares or organ rejection. CONCLUSION: NVX-CoV2601 was safe and immunogenic with similar humoral responses compared to healthy controls, making it a viable alternative for immunosuppressed patients.