• Clinical and Experimental Vaccine Research
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• v.13 no.4
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• pp.348-358
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• 2024

Purpose: We aim to analyze the proportion and level of coronavirus disease 2019 (COVID-19) seropositivity in patients with systemic lupus erythematosus (SLE) and explore factors associated with lower anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike receptor-binding domain (S-RBD) antibody levels. Materials and Methods: A cross-sectional study involving patients with SLE was conducted. We included those aged 18-60 years, either unvaccinated or had received inactivated vaccine (CoronaVac; Sinovac Biotech Ltd., China). Furthermore, participants were tested for anti-SARS-CoV-2 S-RBD antibody levels and SARS-CoV-2 surrogate virus neutralization test, and comparative test analysis was employed. Results: This study included 159 subjects of whom 92 and 67 were SLE subjects and controls, respectively. Significantly higher seropositive results were noted in patients with SLE receiving vaccine (96.9% versus 3.1%). Unvaccinated SLE patients receiving cyclophosphamide (CYC) had higher anti-RBD levels compared to unvaccinated SLE patients not receiving CYC (23.81 [interquartile range (IQR), 2.26-78.85] versus 2.13 [IQR, 0.1-12.5]), whereas vaccinated SLE patients receiving CYC had lower anti-RBD levels compared to vaccinated SLE patients not receiving CYC (15.5 [IQR, 6.62-35.09] and 69.77 [IQR, 17.48-201]). In the vaccinated SLE group, a lower value of anti-SARS-CoV-2 RBD antibody levels was observed in patients receiving mycophenolate mofetil and those with chronic kidney disease. No correlation was noted between disease activity and organ involvement with lower antibody response. Conclusion: The increase in COVID-19 antibody levels in patients with SLE may be affected by exposure to hospital settings and vaccine. Furthermore, CYC treatment is associated with lower antibody response after receiving vaccine.

• Clinical and Experimental Vaccine Research
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• v.12 no.3
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• pp.224-231
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• 2023

Purpose: The Sinovac and AstraZeneca vaccines are the primary coronavirus disease 2019 vaccines in Indonesia. Antibody levels in vaccine-injected individuals will decline substantially over time, but data supporting the duration of such responses are limited. Therefore, this study aims to quantitatively evaluate antibody responses resulting from the completion of Sinovac and AstraZeneca administration in Indonesian adults. Materials and Methods: Participants were divided into two groups based on their vaccine type. Both groups were then assessed on the anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor binding domain (anti-SRBD) concentrations. The anti-SRBD level was measured using Elecsys anti-SARS-CoV-2 S assay and analyzed every month until 3 months after the second vaccination. Results: The results presented significant differences (p=0.000) in immunoglobulin G (IgG) titers among the vaccines' measurement duration, where all samples observed a decrease in IgG titers over time. The mean titer levels of anti-SRBD IgG in the group given Sinovac were high in the first month after vaccination and decreased by 55.7% in 3 months. AstraZeneca showed lesser immune response with a slower decline rate. Adverse effects following immunization (AEFI) showed that systemic reactions are the most reported in both vaccines, with a higher percentage in the second dose of AstraZeneca type vaccines. Conclusion: Sinovac induced more significant titers of anti-SRBD IgG 1 month after the second dose but generated fewer AEFIs. In contrast, AstraZeneca generated more AEFIs, in mild to moderate severity, but provided lower levels of anti-SRBD IgG.