Vaccination remains essential in preventing morbidity of SARS-CoV-2 infections. We previously showed that >10mg/day prednisolone and methotrexate use associated with reduced antibody concentrations after primary vaccination in patients with giant cell arteritis (GCA) and polymyalgia rheumatica (PMR). In this follow-up study, we measured the decay of antibody concentrations and the immunogenicity of SARS-CoV-2 booster vaccination.
GCA/PMR patients included in the primary vaccination (BNT162b2 or ChAdOx1) study were asked again to donate blood samples six months after primary vaccination (n=24) and one month after booster vaccination (n=46, BNT162b2 or mRNA1273). Data were compared to that of age-, sex-, and vaccine-matched controls (n=58 and n=42, respectively). Multiple linear regression was performed with post-booster antibody concentrations as dependent variable and post-primary vaccination antibodies, prednisolone >10mg/day and methotrexate use as predicting variables.
Antibody concentrations decreased faster over time in GCA/PMR patients than in controls, which was associated with prednisolone treatment during primary vaccination. Post-booster antibody concentrations were comparable between patients and controls. Antibody concentrations post primary vaccination, but not treatment during booster vaccination, were predictive for antibody concentrations post booster vaccination.
These results indicate that the decay of humoral immunity after primary vaccination is associated with prednisolone treatment, whereas the subsequent increase after booster vaccination, was not. Patients with low antibody concentrations following primary vaccination remained at an immunogenic disadvantage after a single booster vaccination. This longitudinal study in GCA/PMR patients stresses the importance of repeated booster vaccination for patients with poor responses to primary vaccination. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.