Immunogenicity and safety of the CoronaVac and BNT162b2 Covid-19 vaccine in patients with inflammatory rheumatic diseases and healthy adults: comparison of different vaccines

OBJECTIVES: To determine the seroconversion (SC) rate after CoronaVac and BNT162b2 vaccines in adults with inflammatory rheumatic disease (IRD). METHODS: Patients who were followed up with IRD and who received two doses of either CoronaVac or BNT162b2 vaccines were included in this prospective observational single-center study. Subjects with two doses of CoronaVac or BNT162b2 without known IRD were included in the healthy controls. The blood samples were taken at a minimum of two and a maximum of 12 weeks after the second dose of vaccine. RESULTS: A total of 81 patients with IRD (61 CoronaVac, 20 BNT162b2) and 100 healthy controls (70 CoronaVac, 30 BNT162b2) were included. The SC rate was slightly lower among patients with IRD versus controls (84 vs 97%, p = 0.002). The SC rate was 100% in all participants who received BNT162b2 both in the patient and control group. The IgG antibody level after CoronaVac in the patient group was significantly lower than both the BNT162b2 (p = 0.031) and the healthy group (p < 0.001). Among patients with IRD, those on rituximab (RTX) (12/81,14.8%) had significantly less SC rate (5/12, 41.7%). The median neutralizing antibody titers were significantly higher in patients with BNT162b2 compared with CoronaVac (1.97 vs. 16.34, p < 0.001). CONCLUSIONS: This study showed that all patients with BNT162b2 vaccine developed immunogenicity in patients with IRD, while there was a decreased antibody response with CoronaVac vaccine compared to that of BNT162b2. In particular, RTX significantly reduces the SC rate.