Increased humoral immune response after vaccination with mRNA-1273 vs BNT162b2 in patients with inflammatory rheumatic diseases

ABSTRACT

Patients with inflammatory rheumatic diseases (IRD) have an increased risk for a worse COVID-19 outcome, and impaired immune responses following mRNA COVID-19 vaccines have been observed. In this prospective observational study, we compared the anti-S1 response following vaccination with BNT162b2 and mRNA- 1273 in a large cohort of IRD patients and assessed the effect of different immunomodulatory treatments. Patients from SCQM, the Swiss IRD cohort, who assented to an mRNA COVID-19 vaccine were recruited into the study between 3/2021-9/2021. Participants answered the study questionnaire via the mySCQM patient app and provided self-collected capillary blood samples at baseline, 4, 12, and 24 weeks post second vaccine dose. Samples were tested for IgG antibodies against the S1 domain of the SARS-CoV-2 spike protein using the EUROIMMUN ELISA. We examined differences in antibody titres depending on the vaccine and treatment received, while adjusting for age and history of SARSCoV- 2 infection, by applying mixed effects continuous outcome logistic regression models at each timepoint. Eligible samples were obtained from 564 IRD patients (mean age 53 y (s.d. 12 y), 66% female) with 36% RA, 37%, axSpA, 21% PsA, and 6% UA (undifferentiated arthritis), on no medication (no DMARD & no steroids 15%), csDMARD (9%), TNFi (48%), IL-6/17/23i (14%), JAKi (6%), rituximab (4%), abatacept (3%), and PDE4i (1%) in mono/combination therapy at baseline. 10% of patients had a past SARS-CoV-2 infection, 54% received BNT162b2, 46% mRNA-1273. Independently of the disease, treatment, and history of SARS-CoV- 2 infection, the odds of having higher anti-S1 titres at 4, 12, and 24 weeks post second vaccine dose were, respectively, 3.3, 3.9, and 3.8 times higher with mRNA-1273 compared to BNT162b2 for the average-aged patient of this population (p <0.0001). Moreover, with every year of age, the odds of higher anti-S1 levels increased by 3% to 5% following mRNA-1273 vs BNT162b2 vaccination (p <0.05), indicating an additional benefit for elderly IRD patients. Among monotherapies, rituximab, abatacept, JAKi, and TNFi had the highest odds of reduced anti-S1 responses compared to no medication. Patients on specific combination therapies showed significantly reduced antibody responses compared to respective monotherapies. Our results suggest that in IRD patients, vaccination with mRNA- 1273 vs BNT162b2 results in higher anti-S1 antibody titres, and has an additional benefit in elderly patients.