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Purpose: We aimed to assess the humoral response to and reactogenicity of coronavirus disease 2019 (COVID-19) vaccination according to the vaccine type and to analyze factors associated with immunogenicity in actively treated solid cancer patients (CPs)., Materials and Methods: Prospective cohorts of CPs, undergoing anticancer treatment, and healthcare workers (HCWs) were established. The participants had no history of previous COVID-19 and received either mRNA-based or adenovirus vector-based (AdV) vaccines as the primary series. Blood samples were collected before the first vaccination and after 2 weeks for each dose vaccination. Spike-specific binding antibodies (bAbs) in all participants and neutralizing antibodies (nAbs) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) wild-type, Delta, and Omicron variants in CPs were analyzed and presented as the geometric mean titer., Results: Age-matched 20 HCWs and 118 CPs were included in the analysis. The bAb seroconversion rate and antibody concentrations after the first vaccination were significantly lower in CPs than in HCWs. After the third vaccination, antibody levels in CPs with a primary series of AdV were comparable to those in HCWs, but nAb titers against the Omicron variant did not quantitatively increase in CPs with AdV vaccine as the primary series. The incidence and severity of adverse reactions post-vaccination were similar between CPs and HCWs., Conclusion: CPs displayed delayed humoral immune response after SARS-CoV-2 vaccination. The booster dose elicited comparable bAb concentrations between CPs and HCWs, regardless of the primary vaccine type. Neutralization against the Omicron variant was not robustly elicited following the booster dose in some CPs, implying the need for additional interventions to protect them from COVID-19.

Background: Solid organ transplant recipients (SOTRs) are susceptible to severe coronavirus disease 2019 (COVID-19); however, immunogenicity studies of the Omicron variants per vaccination schedules are still lacking. We examined humoral immunogenicity following third-dose mRNA vaccine administration in Korean SOTRs who received primary COVID-19 vaccine series on homologous or heterologous schedules., Methods: We recruited SOTRs at Severance Hospital from October 27, 2021, to March 31, 2022. Blood samples were collected between 14 days and 5 months after the second and third mRNA vaccine (BNT162b2 or mRNA-1273) doses. SARS-CoV-2 anti-spike IgG titer was analyzed. The neutralization inhibition rate was analyzed using the surrogate neutralization assay for the wild-type, Delta, and Omicron variants., Results: No significant differences existed in the SARS-CoV-2 anti-spike IgG positivity rate between the homologous BNT162b2/BNT162b2/BNT162b2 (85%) and other heterologous groups (83% of ChAdOx1/ChAdOx1/BNT162b2, 90% of ChAdOx1/ChAdOx1/mRNA-1273, and 78% of ChAdOx1/BNT162b2/BNT162b2). No significant difference existed in the neutralization inhibition rates between the four groups for wild-type, Delta, and Omicron variants. Median neutralization inhibition rates against the Omicron variant (2-5%) were significantly lower than those against the wild-type (87-97%) and Delta (55-89%) variants (P < 0.001)., Conclusions: Regardless of the schedule, the neutralization inhibition rate against the Omicron variant was poor; therefore, additional preventive measures are required in such high-risk populations., Competing Interests: Declaration Competing of Interest The authors of this manuscript have no conflicts of interest to disclose, as described by the American Journal of Transplantation., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Solid organ transplant recipients (SOTRs) are vulnerable to severe coronavirus disease 2019 (COVID-19) and exhibit poor antibody responses to COVID-19 vaccines. Herein, we compared the humoral immunogenicity of a mixed vaccine (ChAdOx1 nCoV-19 [ChAd]/BNT162b2 [BNT]) with that of conventional matched vaccines (mRNA, adenoviral vector [AdV-Vec]) in SOTRs., Methods: Serum samples were collected at Severance Hospital (Seoul, Korea) between September and October 2021 (14 d-5 mo after COVID-19 vaccination; V2). The severe acute respiratory syndrome coronavirus 2 antispike IgG titer (BAU/mL; ELISA) and neutralization inhibition (percentage; neutralization assay) were compared between vaccination groups overall and stratified by V2 (poststudy vaccination visit) timing., Results: Of the 464 participants, 143 (31%) received mRNA vaccines, 170 (37%) received AdV-Vec vaccines, and 151 (33%) received mixed vaccines (all ChAd/BNT). The geometric mean titer for the ChAd/BNT group was 3.2-fold higher than that of the AdV-Vec group (geometric mean ratio, 3.2; confidence interval, 1.9-5.4) but lower than that of the mRNA group (geometric mean ratio, 0.4; confidence interval, 0.2-0.7). Neutralization inhibition in the ChAd/BNT group was 32%, which was higher than that in the AdV-Vec group (21%; P < 0.001) but lower than that in the mRNA group (55%; P = 0.02). There was no difference in geometric mean titer by V2 timing (ChAd/BNT, 45 versus 31, days 14-60; mRNA, 28 versus 15, days 61-150)., Conclusions: The ChAd/BNT group showed higher humoral immunogenicity than the AdV-Vec group, with similar immunogenicity to the mRNA vaccine. Nevertheless, immunogenicity following the primary vaccination series was poor in all vaccine groups, supporting the justification for booster vaccination in SOTRs., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Interleukin-6 (IL-6) is a multifunctional cytokine associated with various diseases, including coronavirus disease (COVID-19). Although IL-6 levels can be assessed using serum samples, use of the AFIAS (Boditech Med Inc.) automated immunoassay analyzer enables quick and simple measurement of IL-6 levels in both serum and whole blood specimens. This study aimed to assess the correlation between IL-6 measurements obtained from the AFIAS IL-6 assay and Elecsys IL-6 assay (Roche Diagnostics). Additionally, utilization of the AFIAS IL-6 assay was evaluated., Methods: The IL-6 levels from 113 serum samples quantified using two assay systems were evaluated for their degree of correlation. Meanwhile, the linearity, analytical sensitivity, and precision/reproducibility of the AFIAS IL-6 assay were also assessed., Results: Quantification of IL-6 with the AFIAS IL-6 and Elecsys IL-6 assays showed excellent agreement (kappa 0.802) and were found to be correlated (y = -0.2781 + 1.068x; 95% confidence interval: 1.007-1.124). AFIAS IL-6 showed good analytical performances. IL-6 levels were significantly higher in deceased patients compared to those with non-complicated disease and those who were intubated (p = 0.002 and p < 0.0001, respectively). Finally, IL-6 levels more accurately predicted poor prognosis in patients, than did C-reactive protein (area under the curve, 0.716 vs. 0.634)., Conclusion: The overall analytical performance of the AFIAS assay was comparable to that of the Elecsys IL-6 assay. In light of the ongoing COVID-19 pandemic, the AFIAS may be an attractive tool for measuring IL-6 levels., (© 2021 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

Purpose: Coronavirus disease-2019 (COVID-19) is a novel respiratory infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); there are few specific treatments. Convalescent plasma (CP), donated by people who have recovered from COVID-19, is an investigational therapy for severe or critically ill patients with COVID-19., Materials and Methods: This retrospective cohort study evaluated the effectiveness of CP therapy in patients with severe or life-threatening cases of COVID-19 at two hospitals in Seoul, Korea, between May and September 2020. Clinical outcomes were evaluated in 20 patients with CP therapy in a descriptive manner. Additionally, the changes in cycle threshold (Ct) values of 10 patients with CP therapy were compared to those of 10 controls who had the same (±0.8) initial Ct values but did not receive CP., Results: Of the 20 patients (mean age 66.6 years), 18 received high-dose oxygen therapy using mechanical ventilators or high-flow nasal cannulas. Systemic steroids were administered to 19 patients who received CP. The neutralizing antibody titers of the administered CP were between 1:80 and 1:10240. There were two ABO-mismatched transfusions. The World Health Organization ordinal scale score and National Institutes of Health severity score improved in half of the patients within 14 days. Those who received CP showed a higher increase in Ct values at 24 h and 72 h after CP therapy compared to controls with similar initial Ct values ( p =0.002). No transfusion-related side effects were observed., Conclusion: CP therapy may be a potential therapeutic option in severe or critically ill patients with COVID-19., Competing Interests: The authors have no potential conflicts of interest to disclose., (© Copyright: Yonsei University College of Medicine 2021.)