Inactivated SARS-CoV-2 vaccine in primary Sjögren's syndrome: humoral response, safety, and effects on disease activity.

INTRODUCTION: There is no study specifically focused on SARS-CoV-2 vaccine in primary Sjögren's syndrome (pSS). OBJECTIVES: To assess the immunogenicity, safety, possible effects on disease activity, and autoantibody profile of the Sinovac-CoronaVac vaccine in pSS. METHODS: Fifty-one pSS patients and 102 sex- and age-balanced controls without autoimmune diseases were included in a prospective phase 4 trial of the Sinovac-CoronaVac vaccine (two doses 28 days apart, D0/D28). Participants were assessed in three face-to-face visits (D0/D28 and six weeks after the 2nd dose (D69)) regarding adverse effects; clinical EULAR Sjögren's Syndrome Disease Activity Index (clinESSDAI); anti-SARS-CoV-2 S1/S2 IgG (seroconversion (SC) and geometric mean titers (GMT)); neutralizing antibodies (NAb); and pSS autoantibody profile. RESULTS: Patients and controls had comparable female sex frequency (98.0% vs. 98.0%, p = 1.000) and mean age (53.5 ± 11.7 vs. 53.4 ± 11.4 years, p = 0.924), respectively. On D69, pSS patients presented moderate SC (67.5% vs. 93.0%, p < 0.001) and GMT (22.5 (95% CI 14.6-34.5) vs. 59.6 (95% CI 51.1-69.4) AU/mL, p < 0.001) of anti-SARS-CoV-2 S1/S2 IgG but lower than controls, and also, moderate NAb frequency (52.5% vs. 73.3%, p = 0.021) but lower than controls. Median neutralizing activity on D69 was comparable in pSS (58.6% (IQR 43.7-63.6)) and controls (64% (IQR 46.4-81.1)) (p = 0.219). Adverse events were mild. clinESSDAI and anti-Ro(SS-A)/anti-La(SS-B) levels were stable throughout the study (p > 0.05). CONCLUSION: Sinovac-CoronaVac vaccine is safe in pSS, without a deleterious impact on disease activity, and has a moderate short-term humoral response, though lower than controls. Thus, a booster dose needs to be studied in these patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04754698. Key Points • Sinovac-CoronaVac vaccine is safe in pSS, without a detrimental effect on systemic disease activity, and has a moderate short-term humoral response • A booster dose should be considered in these patients.

Increment of immunogenicity after third dose of a homologous inactivated SARS-CoV-2 vaccine in a large population of patients with autoimmune rheumatic diseases.

OBJECTIVE: To determine the immunogenicity of the third dose of CoronaVac vaccine in a large population of patients with autoimmune rheumatic diseases (ARD) and the factors associated with impaired response. METHODS: Adult patients with ARD and age-balanced/sex-balanced controls (control group, CG) previously vaccinated with two doses of CoronaVac received the third dose at D210 (6 months after the second dose). The presence of anti-SARS-CoV-2 S1/S2 IgG and neutralising antibodies (NAb) was evaluated previously to vaccination (D210) and 30 days later (D240). Patients with controlled disease suspended mycophenolate mofetil (MMF) for 7 days or methotrexate (MTX) for 2 weekly doses after vaccination. RESULTS: ARD (n=597) and CG (n=199) had comparable age (p=0.943). Anti-S1/S2 IgG seropositivity rates significantly increased from D210 (60%) to D240 (93%) (p<0.0001) in patients with ARD. NAb positivity also increased: 38% (D210) vs 81.4% (D240) (p<0.0001). The same pattern was observed for CG, with significantly higher frequencies for both parameters at D240 (p<0.05). Multivariate logistic regression analyses in the ARD group revealed that older age (OR=0.98, 95% CI 0.96 to 1.0, p=0.024), vasculitis diagnosis (OR=0.24, 95% CI 0.11 to 0.53, p<0.001), prednisone ≥5 mg/day (OR=0.46, 95% CI 0.27 to 0.77, p=0.003), MMF (OR=0.30, 95% CI 0.15 to 0.61, p<0.001) and biologics (OR=0.27, 95% CI 0.16 to 0.46, p<0.001) were associated with reduced anti-S1/S2 IgG positivity. Similar analyses demonstrated that prednisone ≥5 mg/day (OR=0.63, 95% CI 0.44 to 0.90, p=0.011), abatacept (OR=0.39, 95% CI 0.20 to 0.74, p=0.004), belimumab (OR=0.29, 95% CI 0.13 to 0.67, p=0.004) and rituximab (OR=0.11, 95% CI 0.04 to 0.30, p<0.001) were negatively associated with NAb positivity. Further evaluation of COVID-19 seronegative ARD at D210 demonstrated prominent increases in positivity rates at D240 for anti-S1/S2 IgG (80.5%) and NAb (59.1%) (p<0.0001). CONCLUSIONS: We provide novel data on a robust response to the third dose of CoronaVac in patients with ARD, even in those with prevaccination COVID-19 seronegative status. Drugs implicated in reducing immunogenicity after the regular two-dose regimen were associated with non-responsiveness after the third dose, except for MTX. Trial registration number NCT04754698.