Vaccination is considered as a cornerstone of the management of COVID-19 pandemic. However, while vaccines provide a robust protection in immunocompetent individuals, the immunogenicity in patients with inflammatory rheumatic diseases (IRD) is not well established.

A monocentric observational study evaluated the immunogenicity of a two-dose regimen vaccine in adult patients with IRD (n=123) treated with targeted or biological therapies. Serum IgG antibody levels against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike proteins were measured after the second vaccination. In addition, a search for observational studies performed in IRD under biologic or targeted therapies up to September 31, 2021 (PROSPERO registration number: CRD42021259410) was undertaken in publication databases, preprint servers, and grey literature sources. Studies that reported sample size, study date, location, and seroprevalence estimate were included. A meta-analysis was conducted to identify demographic differences in the prevalence of SARS-CoV-2 antibodies.

Of 123 patients (median age 66 IQR 57–75), 69.9% have seroconverted after vaccination. Seroconverted patients were older than non-seroconverted ones in our cohort. Rituximab was associated with a significantly low antibody response. Besides, we identified 20 seroprevalence studies in addition to our cohort including 4423 participants in 11 countries. Meta-analysis confirmed a negative impact of rituximab on seroconversion rate and suggested a less substantial effect of abatacept, leflunomide and methotrexate.

Rituximab impairs serological response to SARS-CoV-2 vaccines in patients with IRD. This work suggests also a negative impact of abatacept, methotrexate or leflunomide especially when associated to biological therapy.