Immunogenicity and Safety of Chadox1 Ncov- 19 Vaccine in Primary Sjogren's Syndrome

ABSTRACT

Introduction. There are few studies that evaluated the response to Covid- 19 vaccines, in primary Sjogren's Syndrome (pSS) and none evaluated ChAdOx1 n-Cov19 (AstraZeneca/Fiocruz). The aim of this study was to evaluate the efficacy and safety of the ChAdOx1 n-Cov19, a viral vector vaccine, in pSS compared to healthy control (HC). Methods. Patients with pSS >18 years, classified according to ACR/EULAR 2016 were included. Neutralizing antibodies against the Receptor Binding Domain - RBD portion of the Spike protein of SARS-CoV-2 (IgGS) were measured by chemiluminescence (Abbott), before the first dose (D0) and 28 days after the second dose (D28*). The test is considered reactive if >50 AU/ml. Results. Sixty pSS patients and 62 HC were recruited from a single center (HUCAM-UFES, Vitoria, ES, Brazil). The HC group was homogeneous for sex (92% women) and younger than HC (47+/-11 vs. 39+/-13, p<0.05). In the pSS group, 45.2% were anti-Ro positive, mean ESSDAI was 3.2, 83.3% were using DMARD or immunosuppressant/biological therapy, 31.9% were in high immunosuppression. The frequency of mild adverse events (AE) was similar in both two groups. No serious AE, hospitalizations or death were reported. There was no difference between the PGA ("Patient's Global Assessment") after vaccination (4.5 vs.5, p=0.903). Among seronegative individuals at baseline, the seroconversion rate (100% vs. 89%, p=0.02) was lower, and geometric mean titers (GeoMean IgG-S) was similar in pSS=696.9(CI95%237.6 -2,043) compared to HC=1,986(CI95%1,463-2,697;p=0.316). However, in those with high immunosuppression, the seroconversion (71%, p=0.001) and GeoMean titers were lower 229.4 (CI95%14.64-3,594, p=0.004). Patients in moderate to high disease activity (ESSDAI >=5) showed lower seroconversion (60%, p=0.006) and Geomean titers 31.7 (CI95%0.06-15.4;p=0.004). Conclusions. ChAdOX1 vaccine is safe and induced high GeoMean neutralizing antibodies titers and seroconversion rate in pSS patients similar to HC. Immunossuppression therapy and disease activity decreased the immune response to the vaccine.