Immunogenicity of SARS-CoV-2 Vaccines in Psoriatic Patients on Ongoing Tildrakizumab Therapy: a Monocentric Observational Study

Introduction
Monoclonal antibodies directed against interleukin 23 have substantially improved the treatment of psoriasis in recent years. However, during the coronavirus 2 pandemic disease in 2019, questions arose regarding whether patients receiving such therapy are able to mount an adequate immune response to vaccination against severe acute respiratory syndrome mediated by coronavirus 2. Clinicians have also been concerned about whether the interval between the administration of interleukin 23 inhibitors and vaccination may influence vaccine-induced immunogenicity.

Objective
To assess the immune response to vaccination against severe acute respiratory syndrome due to coronavirus 2 in patients treated with tildrakizumab in routine clinical practice and to identify factors that may affect this immune response.

Material and methods
Patients receiving maintenance treatment with tildrakizumab every twelve weeks and vaccinated against severe acute respiratory syndrome-coronavirus 2 in community vaccination centres were enrolled. Serum samples were analysed for the concentration of antibodies specific to severe acute respiratory syndrome-coronavirus 2 and for the surrogate neutralisation capacity of these antibodies, using an enzyme-linked immunosorbent assay technique.

Results
Sixty-three patients were included. Of these, sixty-one demonstrated a concentration of antibodies against severe acute respiratory syndrome-coronavirus 2 above the manufacturer defined threshold for a positive antibody response. Fifty-four patients exhibited neutralising activity of antibodies against severe acute respiratory syndrome-coronavirus 2 above the assay cut-off value. There was no significant association between the time interval from the last tildrakizumab dose to vaccination and the concentrations of antibodies, including immunoglobulin G, immunoglobulin A and neutralising antibodies (p > 0.05). In contrast, the time elapsed since the most recent vaccination and the vaccination regimen significantly influenced antibody concentrations.

Conclusions
Vaccination against severe acute respiratory syndrome-coronavirus 2 induces adequate antibody formation in patients with psoriasis undergoing treatment with tildrakizumab, and the timing of tildrakizumab administration does not appear to impair vaccine immunogenicity.