• Clinical and Experimental Vaccine Research
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• v.11 no.1
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• pp.116-120
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• 2022

The immunogenicity of CoronaVac among Indonesian adults at the academic premises was investigated. Two doses of CoronaVac vaccine induced a complete seroconversion on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) naïve adults with titers of anti-SARS-CoV-2 receptor-binding domain (RBD) antibodies ranging from 9.1 to 151.9 U/mL. The median value was lower than the one observed in recovered adults with mild coronavirus disease 2019 (38.7 vs. 114.5 U/mL). Nonetheless, 93.6% of the vaccinated adults, in contrast to 76.5% of the recovered adults, displayed inhibition rates above the cut-off to block RBD-angiotensin-converting enzyme 2 binding. This suggests that two doses of CoronaVac were immunogenic and likely to be protective among Indonesian adults.

• Clinical and Experimental Vaccine Research
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• v.11 no.2
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• pp.209-216
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• 2022

Purpose: This study was performed to investigate humoral immune response and adverse events upon the heterologous prime-boost with a single dose of the mRNA-1273 vaccine among fully CoronaVac-vaccinated, infection-naïve healthcare workers in Indonesia. Materials and Methods: One hundred twenty-five eligible healthcare workers were recruited from one hospital for this prospective cohort study. Blood collection was conducted twice, i.e., on 7 days before and 28 days after the booster vaccination. The titer of anti-SARS-CoV-2 receptor-binding domain (RBD) antibodies was quantified accordingly. The post-vaccination adverse event was recorded for both CoronaVac and mRNA-1273 vaccinations. Any breakthrough infection was monitored during the follow-up period. Wilcoxon matched-pairs signed rank test was used to test differences between groups. Results: A significant increase was observed in the titer of anti-SARS-CoV-2 RBD antibodies upon receiving the mRNA-1273 booster (geometric mean titers of 65.57 and 47,445 U/mL in pre-and post-booster, respectively), supporting the argument to use heterologous prime-boost vaccination to improve the protection against COVID-19 in a high-risk population. The mRNA1273 vaccine, however, caused a higher frequency of adverse events than the CoronaVac vaccine. Nonetheless, the adverse events were considered minor medical events and temporary as all subjects were not hospitalized and fully recovered. Of note, no breakthrough infection was observed during the follow-up to 12 weeks post-booster. Conclusion: The heterologous prime-boost vaccination of healthcare workers with a single dose of the mRNA-1273 vaccine generated a significant elevation in humoral immune response towards RBD of SARS-CoV-2 and was associated with a higher frequency, but minor and transient, adverse events.

• Clinical and Experimental Vaccine Research
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• v.13 no.1
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• pp.63-67
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• 2024

This repeated cross-sectional study with two independent sample populations compared the antibody response to severe acute respiratory syndrome coronavirus 2 vaccines in Albania in July-August 2021 and 2022. In 2021, it found higher anti-spike-1 seropositivity and antibody levels in fully vaccinated individuals, especially with BNT162b2 and ChAdOx1 and to a lesser degree with CoronaVac. By 2022, all single-dose recipients showed high antibody responses, suggesting natural infection-enhanced immunity. The study indicates a significant evolution in the antibody response to different coronavirus disease 2019 vaccines and suggests that a single vaccine dose, coupled with natural infection, might suffice to maintain adequate immunity levels in an endemic scenario.

• Pediatric Infection and Vaccine
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• v.29 no.1
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• pp.28-36
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• 2022

Purpose: To evaluate the efficacy and safety of coronavirus disease 2019 (COVID-19) vaccines in children aged 5-11 years, a rapid systematic review was conducted on published clinical trials of COVID-19 vaccines and studies that analyzed real-world data on adverse events after COVID-19 vaccination. Methods: A systematic search was conducted on medical literature in international (Ovid-MEDLINE) and pre-published literature databases (medRxiv), followed by handsearching up to January 4, 2022. We used terms including COVID-19, severe acute respiratory syndrome coronavirus 2, and vaccines, and the certainty of evidence was graded using the GRADE approach. Results: A total of 1,675 studies were identified, of which five were finally selected. Among the five studies, four consisted of data from clinical trials of each of the four types of COVID-19 vaccines (BNT162b2, mRNA-1273, CoronaVac, and BBIBP-CorV). The remaining study consisted of real-world data on the safety of the BNT162b2 vaccine in children aged 5-11 years. This systematic review identified that COVID-19 vaccines in recipients aged 5-11 years produced a favorable immune response, and were vaccines were effective against COVID-19. The safety findings for the BNT162b2 vaccine in children and early adolescents aged 5-11 years were similar to those data noted in the clinical trial. Conclusions: There is limited data on COVID-19 vaccines in children aged 5-11 years. Consequently continuous and comprehensive monitoring is necessary for the evaluation of the safety and effectiveness of the COVID-19 vaccines.

• 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.13 no.4
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• pp.309-314
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• 2024

Purpose: A booster coronavirus disease 2019 (COVID-19) vaccination was proposed to preserve immunity and prevent new variants of the severe acute respiratory syndrome coronavirus 2 virus. The objectives of this study are to investigate clinical manifestations, associated factors and course of cutaneous reactions after the booster dose of COVID-19 vaccination, compared to the recommended 1st and 2nd doses. Materials and Methods: This retrospective cohort study was conducted at Siriraj Hospital, Bangkok. Adult patients who reported cutaneous reactions after COVID-19 vaccination from April 2021 to February 2022 were included. Data were collected from electronic medical records and analyzed. Results: A total of 521 subjects with a median age of 38 years were included. Females predominated (80.2%). Most reactions were reported after receiving CoronaVac (49.1%) and ChAdOx1 nCoV-19 (46.3%). The injection site reaction was the most reported. Twenty-one patients reported rash after the 3rd booster dose, with messenger RNA vaccines in most cases. Patients in this group had significantly fewer injection site reactions compared to those with the 1st and 2nd vaccination (70.6% vs. 91.5%) with an increasing proportion of new-onset urticaria (17.6% vs. 5.4%, p=0.023). The rash after the 3rd booster vaccination tended to have a longer duration of reactions (p=0.001). Boosting with a vaccine different from the 1st dose may not affect the reaction. Age and sex did not affect booster rash. In this study, no serious cutaneous reactions were found. Conclusion: Most adverse cutaneous reactions after COVID-19 vaccination are mild in severity, especially after booster vaccination, and should not discourage the benefits of getting vaccinated.