Evaluation of Reactogenicity and Neutralizing Antibody Responses 6 Months Post-Vaccination with Monovalent COVID-19 Vaccine.

The association between reactogenicity and long-term immunogenicity after coronavirus disease 2019 (COVID-19) vaccination remains unclear. This study investigated whether adverse reactions to ChAdOx1 nCoV-19 or BNT162b2 vaccines correlate with neutralizing antibody responses in severe acute respiratory syndrome coronavirus 2 infection-naïve healthcare workers. Blood samples were collected at three time points to measure neutralizing antibodies.

Cytokine profiles associated with persisting symptoms of post-acute sequelae of COVID-19.

Background/aims: Post-acute sequelae of COVID-19 (PASC) are highly heterogeneous; therefore, the pathophysiological mechanisms for PASC remain unclear. In this study, we aimed to examine the immunologic aspects of various PASC symptoms.

Methods: We prospectively enrolled adults aged ≥ 18 years who were diagnosed with COVID-19 between August 2022 and September 2023.

Risk and Distribution of Metastatic Infections by Primary Infection Focus in Bacteremia.

Background: bacteremia (SAB) is a significant cause of morbidity and mortality, with a high risk of metastatic infections. Understanding the timing and distribution of metastatic infections based on the primary infection focus is crucial for effective management. We aimed to identify patterns that could guide clinicians in prioritizing surveillance and interventions for patients at high risk of metastatic infection.

Species-specific risk of ophthalmic involvement in candidaemia: a propensity-matched competing risk analysis.

Objectives: Given the limited data on species-specific ocular involvement in candidaemia, we aimed to assess the differential risk of ocular involvement according to Candida species in patients with candidaemia.

Methods: A retrospective review was conducted of patients with candidaemia who underwent funduscopic examination at a tertiary centre in Seoul, Republic of Korea between January 2014 and December 2023. Ocular involvement, defined as endophthalmitis, was determined by two retinal specialists.

The clinical impact of prolonged steroid therapy in severe COVID-19 patients: a retrospective cohort study with propensity score matching.

Background: The optimal duration of steroid therapy for patients with COVID-19 remains unclear. This study compared clinical outcomes between early steroid withdrawal (EW; ≤10 days) and prolonged steroid tapering (PT; >10 days) in patients with severe COVID-19 requiring oxygen support.

Methods: This retrospective, single-center cohort study included adult patients with COVID-19 and WHO-CPS scores of 6-9 admitted to a tertiary hospital in Seoul, Republic of Korea.

Impact of fluoroquinolone exposure on the diagnosis and prognosis of tuberculosis in immunocompromised patients: a propensity-score-matched, competing risk analysis.

Objectives: Tuberculosis (TB) in immunocompromised patients presents a significant diagnostic challenge. These patients are sometimes empirically treated with quinolones before a definitive diagnosis is established. However, there are limited data on the impact of fluoroquinolone exposure on TB diagnosis and outcomes in these patients.

Mucormycosis coinfection in patients with proven aspergillosis.

Data on the coinfection of molds are limited. Therefore, we systematically investigated mucormycosis coinfection in patients with morphologically proven aspergillosis. The medical records of adult patients with proven aspergillosis and available formalin-fixed paraffin-embedded (FFPE) tissue sections were retrospectively reviewed at a tertiary hospital between January 2019 and July 2024.

Initial and peak serum levels of Krebs von den Lungen-6 for predicting the prognosis of patients with COVID-19.

Background/aims: Krebs von den Lungen-6 (KL-6) is associated with prognosis in patients with COVID-19. However, there is limited data on the correlation between the prognosis of COVID-19 and varying KL-6 levels at different time points. We investigated the optimal cutoff values of the initial and peak serum KL-6 levels to predict mortality and evaluated their correlation with mortality.

Reinfection of SARS-CoV-2 Variants in Immunocompromised Patients with Prolonged or Relapsed Viral Shedding.

Background: Immunocompromised patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection often have prolonged viral shedding, and some are clinically suspected of reinfection with different SARS-CoV-2 variants. However, data on this issue are limited. This study investigated the SARS-CoV-2 variants in serially collected respiratory samples from immunocompromised patients with prolonged viral shedding for over 12 weeks or relapsed viral shedding after at least 2 weeks of viral clearance.

Risk Factors for Infection-Attributable Mortality in Patients With Bacteremia: A Competing Risk Analysis.

Background: Identifying risk factors for mortality in patients with bacteremia (SAB) is crucial due to its high fatality. However, data on risk factors for infection-attributable deaths considering competing risk events such as non-infection-attributable deaths remain limited. We performed a competing risk analysis to elucidate risk factors associated with 30-day infection-attributable mortality in a large cohort of patients with SAB.

Predicting persistent SARS-CoV-2 shedding in immunocompromised patients: a probability-based approach.

Background: Although recommended isolation periods for Coronavirus disease 2019 (COVID-19) have been shortened as the pandemic has subsided, prolonged Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) shedding remains common in immunocompromised patients. This study estimated the probability of viral clearance in these patients based on elapsed days and specific risk factors.

Methods: We prospectively enrolled immunocompromised patients with a confirmed COVID-19 diagnosis from January 2022 to May 2023 during the Omicron variant era.

Viral, Immunologic, and Laboratory Parameters in Patients With and Without Post-Acute Sequelae of SARS-CoV-2 Infection (PASC).

Background: The pathophysiological mechanisms underlying the post-acute sequelae of severe acute respiratory syndrome coronavirus 2 infection (PASC) are not well understood. Our study aimed to investigate various aspects of theses mechanisms, including viral persistence, immunological responses, and laboratory parameters in patients with and without PASC.

Methods: We prospectively enrolled adults aged ≥ 18 years diagnosed with coronavirus disease 2019 (COVID-19) between August 2022 and July 2023.

Clinical and microbiological characteristics of persistent Staphylococcus aureus bacteremia, risk factors for mortality, and the role of CD4 T cells.

This study evaluated the determinants of mortality and the T cell immune response in patients with persistent Staphylococcus aureus bacteremia (SAB). This was a prospective cohort study and patients with confirmed SAB were enrolled from 2008 to 2020. We compared clinical, microbiological, and genotypic features between surviving and deceased patients with persistent SAB.

Comparison of the Clinical Outcomes Between Early and Delayed Transplantation After SARS-CoV-2 Infection.

Our study analyzed 95 solid organ transplant (SOT) and 78 hematopoietic stem cell transplant (HSCT) recipients with prior coronavirus disease 2019 (COVID-19). Patients who underwent transplantation within 30 days of COVID-19 infection comprised the early group, and those who underwent transplantation post-30 days of COVID-19 infection comprised the delayed group. In the early transplantation group, no patient, whether undergoing SOT and HSCT, experienced COVID-19-associated complications.

The Association Between Antibody Responses and Prolonged Viable Severe Acute Respiratory Syndrome Coronavirus 2 Shedding in Immunocompromised Patients: A Prospective Cohort Study.

Immunocompromised patients with coronavirus disease 2019 were prospectively enrolled from March to November 2022 to understand the association between antibody responses and severe acute respiratory syndrome coronavirus 2 shedding. A total of 62 patients were analyzed, and the results indicated a faster decline in genomic and subgenomic viral RNA in patients with higher neutralizing and S1-specific immunoglobulin G (IgG) antibodies (both P < .001).