Fifty-three AAV patients and 106 Controls (CG) received CoronaVac on days D0 (first dose), D28(second dose), and D210 (booster dose, 32 AAV 32 CG). The primary outcome was immunogenicity after the second vaccinedose (day 69) assessed by Seroconversion Rates (SC) of anti-SARS-CoV-2 S1/S2 IgG and Neutralizing Antibodies (NAb). Secondary outcomes were safety, immunogenicity (D28/D240), 6-months antibody decay (D210) and the booster dose response (D240).
Results:
At D69 SC (65.1% vs. 96.8%, p = 0.0001), GMT (21.3 UA/mL vs. 67.7 UA/mL, p < 0.001) and NAb- positivity (53.7% vs. 80.6%, p = 0.001) were moderate but lower in naïve-AAV patients than CG. Patients without SC used more often IS (93.3% vs. 53.3%, p = 0.015), mycophenolate mofetil (20% vs. 0%, p = 0.037) and prednisone (60.0% vs. 28.6%, p = 0.057) than seroconverted. NAb negativity in AAV patients was associated with prednisonetreatment (57.9% vs. 18.2%, p = 0.015) and IS (84.2% vs. 55.0%, p = 0.046). Logistic regressionanalysis models showed that only prednisone was associated with lower seroconversion (OR = 0.2, 0,95% CI 0.05-0.86, p = 0.030) and with lower NAb positivity (OR = 0.2, 0,95% CI 0.05-0.88, p = 0.034). After six months (D69-D210) a decrease in IgG positivity occurred in 32 AAV patients (15.7%, p = 0.074) and 32 CG (18.7%, p = 0.041). For the NAb positivity, the 6-month decrease was not significant (p = 0.114) whereas a major reduction occurred for CG (p < 0.001). A booster dose (D240) resulted in an increment in IgG-positivity (21.9%, p = 0.023) and NAb-positivity (34.4%, p = 0.006) in AAV patients. No moderate/severe adverse events attributable to the vaccine were observed.
Conclusion:
This study provides novel data on the excellent safety and moderate immunogenicity of CoronaVac in AAV patients. A six-month mild antibody waning was observed with a good response to the booster dose, although levels remained lower than CG (CoronavRheum-NCT04754698).