AB1150 IMMUNOGENICITY AND SAFETY OF THE CORONOVAC AND BNT162b2 COVID-19 VACCINE IN PATIENTS WITH INFLAMMATORY RHEUMATIC DISEASES AND HEALTHY ADULTS: COMPARISON OF DIFFERENT VACCINES

Abstract

BackgroundHaving an autoimmune disease was an exclusion criterion in the efficacy and safety phase studies of vaccines against Covid-19 (1-2). In Turkey vaccination first started with the inactivated CoronaVac, then with the mRNA BNT162b2 vaccine. Although there are studies on vaccine efficacy and safety in adults with inflammatory rheumatic disease (IRD), there are still many unknowns (3-4).ObjectivesPrimary outcome of this study is to determine the seroconversion (SC) rate after CoronaVac and BNT162b2 vaccines in adults with IRD and to compare it with a healthy control group. Secondary outcomes are to evaluate whether there are efficacy differences in the two vaccine types, and to investigate the effects of the biologic agent used in the patient group on the vaccine immunogenicity.MethodsThis prospective observational single center study was conducted at the Gazi University Hospital. Patients who were followed up in our outpatient clinic with IRD and who received two doses of either CoronaVac or BNT162b2 vaccines were included. Subjects with two doses one of these vaccine without IRD were included in the healthy control group. Patients who had Covid-19 infection before or during vaccination were excluded. The demographic characters were recorded. The interval between the two doses was 4 weeks. The blood samples of the patient and control groups were taken a minimum of two and a maximum of 12 weeks after the second dose. Anti-S antibodies against SARS-CoV-2 spike proteins were evaluated with the IgG Abbott kit, and a value above 50 arbitrary unit/ml was considered as positive SC. The neutralizing antibody titers were evaluated with the DIA.PRO kit, and cut-off value was above 1 Co/S.ResultsThe 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 was significantly lower than that of BNT162b2 vaccine (p:0.031) in both patient and healthy controls (p:0.001). Among patients with IRD, those on rituximab (RTX)(12/81, %14.8) had significantly less SC rate (5/12, 41.7%) compared to patients on other biologicals (63/69, 91.3%) (p<0.001).ConclusionThis 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 the healthy control group. In particular, the use of RTX significantly reduces the SC rate.