Background: mRNA SARS-CoV-2 vaccines are effective in reducing severe COVID-19 in the general population. However, a comprehensive study of the postvaccination immune response to SARS-CoV-2 has not been done in patients on dupilumab, benralizumab, or mepolizumab.

Aim: Assess the post-vaccination SARS-CoV-2-specific immune responses in patients on dupilumab, benralizumab, or mepolizumab.

Methods: We enrolled healthy controls and patients with severe asthma or atopic dermatitis on dupilumab, benralizumab, or mepolizumab in a prospective, observational trial. All subjects had an initial 2-dose SARS-CoV-2 mRNA vaccination. We used a multiplexed immunoassay to measure antibody levels, a pseudotyped virus luciferase-based assay and a life virus infection inhibition assay to quantify their neutralization activity, and spectral flow cytometry to quantify antigen-specific lymphocytes (using a SARS-CoV-2 protein tetramer-based detection for B cells and activation-induced markers for T cells after 24h incubation with viral peptides).

Results: We collected samples from 46 healthy controls and 57 patients on biologics during a 6-month follow-up after the second vaccine dose. Compared to healthy controls, patients on biologics had lower levels of SARS-CoV-2 antibodies (p=0.001), pseudovirus neutralization (p=0.0002), live virus neutralization (p=0.0069), and frequencies of Spike-specific B cells (p=0.02). There were no significant differences in antigen-specific CD4 (p=0.26) or CD8 (p=0.70) T cells between the groups.

Conclusion: Post-vaccination SARS-CoV-2 antibody and B cell but not T cell responses are lower in patients on biologics than in healthy controls.