Effectiveness of regdanvimab treatment for SARS-CoV-2 delta variant, which exhibited decreased in vitro activity: a nationwide real-world multicenter cohort study.

Background: Immune-evading severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants are emerging continuously. The clinical effectiveness of monoclonal antibody agents that exhibit decreased in vitro activity against SARS-CoV-2 variants needs to be elucidated. Methods: A nationwide, multicenter, retrospective cohort study was designed to evaluate the effectiveness of regdanvimab, an anti-SARS-CoV-2 monoclonal antibody agent. Regdanvimab was prescribed in South Korea before and after the emergence of the delta variant, against which the in vitro activity of regdanvimab was decreased but present. Mild to moderate coronavirus 2019 (COVID-19) patients with risk factors for disease progression who were admitted within seven days of symptom onset were screened in four designated hospitals between December 2020 and September 2021. The primary outcomes, O2 requirements and progression to severe disease within 21 days of admission, were compared between the regdanvimab and supportive care groups, with a subgroup analysis of delta variant-confirmed patients. Results: A total of 2,214 mild to moderate COVID-19 patients were included, of whom 1,095 (49.5%) received regdanvimab treatment. In the analysis of the total cohort, significantly fewer patients in the regdanvimab group than the supportive care group required O2 support (18.4% vs. 27.1%, P < 0.001) and progressed to severe disease (4.0% vs. 8.0%, P < 0.001). In the multivariable analysis, regdanvimab was significantly associated with a decreased risk for O2 support (HR 0.677, 95% CI 0.561-0.816) and progression to severe disease (HR 0.489, 95% CI 0.337-0.709). Among the 939 delta-confirmed patients, O2 support (21.5% vs. 23.5%, P = 0.526) and progression to severe disease (4.2% vs. 7.3%, P = 0.055) did not differ significantly between the regdanvimab and supportive care groups. In the multivariable analyses, regdanvimab treatment was not significantly associated with a decreased risk for O2 support (HR 0.963, 95% CI 0.697-1.329) or progression to severe disease (HR 0.665, 95% CI 0.349-1.268) in delta-confirmed group. Conclusions: Regdanvimab treatment effectively reduced progression to severe disease in the overall study population, but did not show significant effectiveness in the delta-confirmed patients. The effectiveness of dose increment of monoclonal antibody agents should be evaluated for variant strains exhibiting reduced susceptibility.

Correlates of burnout among healthcare workers during the COVID-19 pandemic in South Korea.

Burnout is a form of negative emotional and physical response to job stress. This study aimed to investigate the prevalence of burnout among healthcare workers responding to the coronavirus disease 2019 (COVID-19) outbreak in Korea and to explore correlates of burnout among healthcare workers. A nationwide questionnaire-based survey was conducted from December 1, 2020, to January 29, 2021 on 1425 healthcare workers who worked in one of the 16 healthcare facilities designated for COVID-19 care, in public health centers, or as paramedics in Korea. Burnout was assessed using 16 Korean-adapted items based on the Oldenburg Burnout Inventory (OLBI). Data were collected using a structured questionnaire and analyzed using the R version 4.1.1 software program. OLBI results indicate clinically exhaustion in 84.5% (1204/1425) and clinically disengagement in 91.1% (1298/1425), and 77.3% (1102/1425) met the score criteria for both the exhaustion and disengagement subscales for burnout. Burnout rate was significantly increased in the group with chronic fatigue symptoms (Fatigue Severity Scale ≥ 3.22) after the outbreak of COVID-19 (OR, 3.94; 95% CI 2.80-5.56), in the female group (OR, 2.05; 95% CI 1.46-2.86), in the group with physical symptoms (Patient Health Questionnaire-15 ≥ 10) after the outbreak of COVID-19 (OR, 2.03; 95% CI 1.14-3.60), in the group with a higher Global Assessment of Recent Stress scale (OR, 1.71; 95% CI 1.46-2.01), in the group with post-traumatic stress symptoms (Primary Care Post-Traumatic Stress Disorder-5 ≥ 2) (OR, 1.47; 95% CI 1.08-2.01), and in the younger age group(OR, 1.45; 95% CI 1.22-1.72). The chronic fatigue symptoms were correlated with cumulative days of care (OR, 1.18; 95% CI 1.02-1.37). The physical symptoms were correlated with average contact hours with COVID-19 patients per day (OR, 1.34; 95% CI 1.17-1.54), and cumulative days of care (OR, 1.21; 95% CI 1.06-1.38). Most Korean healthcare workers suffered from burnout related to excessive workload during the COVID-19 pandemic. During a widespread health crisis like COVID-19, it is necessary to regularly check the burnout status in healthcare workers and reduce their excessive workload by supplementing the workforce and providing appropriate working hours sufficient rest hours.

Adverse Reactions after BNT162b2 Messenger RNA Vaccination for Coronavirus Disease 2019 in Healthcare Workers Compared with Influenza Vaccination.

This study aimed to compare adverse reactions following BNT162b2 and influenza vaccinations in healthcare workers. This study included healthcare workers who received the BNT162b2 vaccine and/or inactivated influenza vaccine, quadrivalent (IIV4), on 18-29 October 2021 at a tertiary hospital in Korea. IIV4 was administered and BNT162b2 was subsequently administered one week later. The participants responded to a mobile questionnaire regarding adverse events. The overall adverse reaction rates were 90.6% in the BNT162b2 + IIV4 group, 90.4% in the BNT162b2 alone group, and 44.1% in the IIV4 alone group (p < 0.001). Fever occurred in 19.5%, 26.9%, and 3.3% of participants in the BNT162b2 + IIV4, BNT162b2 alone, and IIV4 alone groups, respectively (p < 0.001). The most common local and systemic adverse reactions were injection site pain (65.0%) and fatigue (58.6%), respectively. Injection-site pain was experienced by 88.7%, 88.5%, and 37.5% of the BNT162b2 + IIV4, BNT162b2 alone, and IIV4 alone groups, respectively (p < 0.001). Fatigue was experienced by 74.8%, 78.8%, and 38.6% of the BNT162b2 + IIV4, BNT162b2 alone, and IIV4 alone groups, respectively (p < 0.001). Adverse reactions occurred at a significantly higher frequency after BNT162b2 than after IIV4. The frequency of adverse reactions one week after vaccination with IIV4 and BNT162b2 was not different from that after vaccination with BNT162b2 alone. Therefore, coadministration of influenza vaccine with BNT162b2 can be expected to be safe.

Psychological Effects of COVID-19 Patient Management Experience among Paramedics and Emergency Medical Technicians: A Nationwide Survey in Korea.

BACKGROUND: Throughout the coronavirus disease 2019 (COVID-19) pandemic, not only medical personnel but also paramedics or emergency medical technicians (EMT) have faced multiple physical and psychological challenges while performing their duties. The current study aimed to evaluate the psychological effects of managing patients with COVID-19 on the paramedics and EMT. MATERIALS AND METHODS: A survey targeting paramedics and EMT in Korea was conducted in December 2020. An official letter requesting participation and with the link to an online-based survey was sent to the Public Emergency Medical Services. Only one response was accepted from each participant. RESULTS: A total of 326 paramedics and EMT responded to the survey. Among them, 66.3% (216/326) had experience in managing patients with COVID-19. No differences in the distribution of sex, age, working area, duration of working experience, and underlying comorbidities were observed between those who did (COVID-19 group) and did not (non-COVID-19 group) experience managing patients with COVID-19. The percentage of participants who showed severe posttraumatic stress disorder (PTSD) symptoms was significantly higher in the COVID group than in the non-COVID group (11.1% vs. 3.6%, P = 0.029). The participants in the COVID group had a significantly higher mean Global Assessment of Recent Stress Scale score than those in the non-COVID group (18.7 ± 11.1 vs. 16.1 ± 9.9, P = 0.042). The proportion of paramedics and EMT willing to leave their job if given a chance was higher in the COVID group than the non-COVID group (24.1% vs. 9.1%, P = 0.001). Additionally, paramedics and EMT in the COVID group tended to show concern regarding exposure to COVID-19 infection. CONCLUSION: The experience of managing patients with COVID-19 resulted in psychological distress among paramedics and EMT in Korea.

Healthcare Workforce Response to The Coronavirus Disease Outbreak in Daegu, Korea: A Multi-Center, Cross-Sectional Survey.

BACKGROUND: Securing an available healthcare workforce is critical to respond to coronavirus disease 2019 (COVID-19); however, research investigating Korea's COVID-19 staffing response is rare. To present the fundamental data of healthcare staff in response to the surge in COVID-19 cases, we investigated the healthcare workforce response in Daegu, South Korea, which experienced the first largest outbreak of COVID-19 outside of China. MATERIALS AND METHODS: In response to the COVID-19 outbreak, this retrospective cross-sectional study analyzed data on the scale and characteristics of healthcare workers (HCWs). Additionally, it analyzed the clinical and epidemiological characteristics of HCWs infected with COVID-19 in six major teaching hospitals (five tertiary and one secondary) in Daegu from January 19 to April 30, 2020. RESULTS: During this study period, only 1.3% (n = 611) of the total hospitalized patients (n = 48,807) were COVID-19 inpatients, but they occupied 6.0% (n = 303) of the total hospital beds (n = 5,056), and 23.7% (n = 3,471) of all HCWs (n = 14,651) worked in response to COVID-19. HCWs participating in COVID-19-related works comprised 50.6% (n = 1,203) of doctors (n = 2,379), 26.3% (n = 1,571) of nurses (n = 5,982), and 11.4% (n = 697) of other HCWs (n = 6,108). Only 0.3% (n = 51) of HCWs (n = 14,651) developed COVID-19 infections from community-acquired (66.7%) or hospital-acquired (29.4%). Nurses were affected predominantly (33.3%), followed by doctors (9.8%), caregivers (7.8%), radiographers (5.9%), and others (45.1%), including nurse aides and administrative, facility maintenance, telephone appointment centers, and convenience store staff. All HCWs infected with COVID-19 recovered completely. The 32.7% (n = 333) of individuals (n = 1,018) exposed to HCWs who had COVID-19 were quarantined, and only one case of secondary transmission among them occurred. CONCLUSION: The COVID-19 pandemic has necessitated significant staffing and facility usage, which is disproportionate to the relatively low number of COVID-19 inpatients, imposing a substantial burden on healthcare resources. Therefore, beyond the current reimbursement level of the Korean National Health Insurance, a new type of rewarding system is needed to prepare hospitals for the emerging outbreaks of infectious diseases. Keeping HCWs safe from COVID-19 is crucial for maintaining the healthcare workforce during a sudden massive outbreak. Further studies are needed to determine the standards of required HCWs through detailed research on the working hours and intensity of HCWs responding to COVID-19.

One Year Follow-Up of COVID-19 Related Symptoms and Patient Quality of Life: A Prospective Cohort Study.

PURPOSE: Globally, concerns have grown regarding the long-term effects of novel coronavirus disease (COVID-19) infection. Therefore, we evaluated the long-term course of persistent symptoms and patient quality of life. MATERIALS AND METHODS: This prospective cohort study was conducted at a single tertiary university hospital from August 31, 2020 to March 29, 2021 with adult patients followed at 6 and 12 months after acute COVID-19 symptom onset or diagnosis. Clinical characteristics, self-reported symptoms, EuroQol 5 dimension 5 level (EQ5D-5L) index scores, Korean version of the Patient Health Questionnaire-9 (PHQ-9), Korean version of the Posttraumatic Stress Disorder Checklist-5 (PCL-5-K), and Generalized Anxiety Disorder-7 (GAD-7) were investigated. Symptom persistent or non-persistent groups were defined according to persistency of COVID-19 related symptoms or signs after acute COVID-19 infection, respectively. RESULTS: Of all 235 patients, 170 (64.6%) patients were eligible for analysis. The median age was 51 (interquartile range, 37-61) years old, and 102 patients were female (60.0%). After 12 months from acute COVID-19 infection, in total, 83 (48.8%) patients still suffered from COVID-19-related symptoms. The most common symptoms included amnesia (24.1%), insomnia (14.7%), fatigue (13.5%), and anxiety (12.9%). Among the five EQ5D-5L categories, the average value of anxiety or depression was the most predominant. PHQ-9 and PCL-5-K scores were statistically higher in the COVID-19-related symptom persistent group than the non-persistent group (p=0.001). However, GAD-7 scores showed no statistical differences between the two groups (p=0.051). CONCLUSION: Neuropsychiatric symptoms were the major COVID-19-related symptoms after 12 months from acute COVID-19 infection, reducing quality of life.

Plasma Biomarkers of Neuropathogenesis in Hospitalized Patients With COVID-19 and Those With Postacute Sequelae of SARS-CoV-2 Infection.

BACKGROUND AND OBJECTIVES: Although patients hospitalized with COVID-19 frequently present with encephalopathy, those with mild initial COVID-19 disease who never required hospitalization also often develop neurologic symptoms as part of postacute sequelae of severe acute respiratory coronavirus type 2 (SARS-CoV-2) infection (neuro-PASC). The pathogenic mechanisms of COVID-19 encephalopathy and neuro-PASC are unknown. We sought to establish biochemical evidence of CNS injury in those patients and their association with neuropsychiatric manifestations and SARS-CoV-2 antigenemia. METHODS: We recruited hospitalized, posthospitalized, and nonhospitalized patients with confirmed diagnosis of COVID-19 with neurologic symptoms in addition to healthy control (HC) subjects. Plasma neurofilament light chain (pNfL), plasma glial fibrillary acidic protein (pGFAP), and plasma SARS-CoV-2 Nucleocapsid antigen (pN Ag) were measured by HD-X Simoa analyzer (Quanterix) and compared with neuropsychiatric symptoms, patient-reported quality-of-life measures, and standardized cognitive assessments. Neuroglial scores (pGFAP/pNfL) were calculated to estimate the relative contribution of astroglial and neuronal involvement. RESULTS: We enrolled a total of 64 study participants, including 9 hospitalized patients with COVID-19 encephalopathy (CE), 9 posthospitalization neuro-PASC (PNP) patients, 38 nonhospitalized neuro-PASC (NNP) patients, and 8 HC subjects. Patients with CE were older, had higher pNfL and pGFAP concentrations, and more frequent pN Ag detection than all neuro-PASC groups. PNP and NNP patients exhibited similar PASC symptoms, decreased quality-of-life measures, and cognitive dysfunction, and 1 of the 38 (2.6%) NNP patients had pN Ag detectable 3 weeks postsymptoms onset. Patients with neuro-PASC presenting with anxiety/depression had higher neuroglial scores, which were correlated with increased anxiety on quality-of-life measures. DISCUSSION: pNfL, pGFAP, and pN Ag measurements indicate neuronal dysfunction and systemic involvement in hospitalized COVID-19 patients with encephalopathy. Detection of SARS-CoV-2 N Ag in blood 3 weeks after symptoms onset in a nonhospitalized patient suggests that prolonged antigenic stimulation, or possibly latent infection, may occur. Anxiety was associated with evidence of astroglial activation in patients with neuro-PASC. These data shed new light on SARS-Cov-2 neuropathogenesis and demonstrate the value of plasma biomarkers across the COVID-19 disease spectrum.

Workload of Healthcare Workers During the COVID-19 Outbreak in Korea: A Nationwide Survey.

BACKGROUND: As the coronavirus disease 2019 (COVID-19) pandemic is ongoing, heavy workload of healthcare workers (HCWs) is a concern. This study investigated the workload of HCWs responding to the COVID-19 outbreak in South Korea. METHODS: A nationwide cross-sectional survey was conducted from September 16 to October 15, 2020, involving 16 healthcare facilities (4 public medical centers, 12 tertiary-care hospitals) that provide treatment for COVID-19 patients. RESULTS: Public medical centers provided the majority (69.4%) of total hospital beds for COVID-19 patients (n = 611), on the other hand, tertiary care hospitals provided the majority (78.9%) of critical care beds (n = 57). The number of beds per doctor (median [IQR]) in public medical centers was higher than in tertiary care hospitals (20.2 [13.0, 29.4] versus 3.0 [1.3, 6.6], P = 0.006). Infectious Diseases physicians are mostly (80%) involved among attending physicians. The number of nurses per patient (median [interquartile range, IQR]) in tertiary-care hospitals was higher than in public medical centers (4.6 [3.4-5] vs. 1.1 [0.8-2.1], P = 0.089). The median number of nurses per patient for COVID-19 patients was higher than the highest national standard in South Korea (3.8 vs. 2 for critical care). All participating healthcare facilities were also operating screening centers, for which a median of 2 doctors, 5 nurses, and 2 administrating staff were necessary. CONCLUSION: As the severity of COVID-19 patients increases, the number of HCWs required increases. Because the workload of HCWs responding to the COVID-19 outbreak is much greater than other situations, a workforce management plan regarding this perspective is required to prevent burnout of HCWs.

Regdanvimab in patients with mild-to-moderate SARS-CoV-2 infection: A propensity score-matched retrospective cohort study.

BACKGROUND: Regdanvimab (CT-P59) is a neutralizing antibody authorized in Republic of Korea for the treatment of adult patients with moderate or mild-COVID-19 who are not on supplemental oxygen and have high risk of progressing to severe disease (age ≥ 50 years or comorbidities). This study evaluated the clinical efficacy, safety and medical utilization/costs associated with real-world regdanvimab therapy. METHODS: This non-interventional, retrospective cohort study included adult patients with confirmed mild-to-moderate SARS-CoV-2 infection. Patients treated with regdanvimab were compared with controls who had received other therapies. The primary endpoint was the proportion of patients progressing to severe/critical COVID-19 or death due to SARS-CoV-2 infection up to Day 28. Propensity score matching was applied to efficacy analyses. RESULTS: Overall, 552 patients were included in the Safety and Efficacy Sets (regdanvimab, n = 156; control, n = 396) and 274 patients in the propensity score-matched (PSM) Efficacy Set (regdanvimab, n = 113; control, n = 161). In the PSM Set, the risk of severe/critical COVID-19 or death was significantly lower in the regdanvimab group (7.1% vs 16.1%, P = 0.0263); supplemental oxygen was required by 8.0% and 18.6% of patients in the regdanvimab and control groups, respectively (P = 0.0128). There were no unexpected safety findings in the regdanvimab group. Medical utilization analysis showed an overall cost reduction with regdanvimab compared with control treatments. CONCLUSIONS: Regdanvimab significantly reduced the proportion of patients progressing to severe/critical disease or dying of SARS-CoV-2 infection. This study shows the potential benefits of regdanvimab in reducing disease severity and improving medical utility in patients with COVID-19.

Patients presenting high fever with lymphadenopathy after COVID-19 vaccination were diagnosed with hemophagocytic lymphohistiocytosis.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still continuing worldwide. Currently, two mRNA-based vaccines and two DNA vaccines using an adenovirus vector are representative vaccines. Since the SARS-CoV-2 vaccines began to be administered, a significant decrease in new infections and COVID-19-associated death has been reported. However, various adverse events from mild symptoms to death have also been described after vaccination. CASE DESCRIPTION: Patients with high fever and lymphadenopathy who are diagnosed with hemophagocytic lymphohistiocytosis (HLH) after COVID-19 vaccination are very rare, and there is no standard management guideline for these patients thus far. Herein, we described two cases of HLH after the administration of an mRNA-based vaccine and adenovirus vector vaccine. DISCUSSION: HLH is a life-threatening hyperinflammatory syndrome that occurs due to persistent stimulation of lymphocytes and histiocytes in various underlying conditions at all ages. Although the exact mechanisms and risk factors of COVID-19 vaccination-related HLH are still unknown, vigorous immune stimulation may trigger a huge cytokine storm, rarely resulting in HLH. It is important to note that early suspicion by clinicians can lower the mortality rate.

Compassionate Use of GC5131 (Hyperimmunoglobulin) Therapy in Critically Ill Patients Diagnosed with COVID-19: A Case Series and Review of Literature.

Presently, the use of convalescent plasma and hyperimmunoglobulin obtained from individuals who have recovered from coronavirus disease 2019 (COVID-19) has proved to potentially provide passive antibody-based immunity, thereby leading to several clinical trials to develop an immune-based COVID-19 treatment. However, the therapeutic efficacy of hyperimmunoglobulin in critically ill patients with COVID-19 remains unknown. On 23 October 2020, we first administered GC5131 in a compassionate-use program to critically ill patients at the Kyungpook National University, Chilgok Hospital, Korea. Since then, five more critically ill patients were treated with GC5131 in this compassionate-use program in our hospital up until 17 December 2020. We retrospectively reviewed the clinical responses of six critically ill patients diagnosed with COVID-19 who received the hyperimmunoglobulin concentrate, GC5131, which was produced by the Green Cross Corporation. After the administration of GC5131, five patients died due to an exacerbation of COVID-19 pneumonia. GC5131 was ineffective when administered to critically ill patients with COVID-19. Nevertheless, we propose that to expect a therapeutic effect from GC5131, it should be administered as early as possible to avoid the excessive inflammatory response phase in patients with severe and advanced COVID-19 infection. This step was difficult to achieve in the real world due to the time required for decision making and the process of the compassionate-use program.

New Scoring System for Predicting Mortality in Patients with COVID-19.

PURPOSE: We aimed to develop a novel mortality scoring system for inpatients with COVID-19 based on simple demographic factors and laboratory findings. MATERIALS AND METHODS: We reviewed and analyzed data from patients who were admitted and diagnosed with COVID-19 at 10 hospitals in Daegu, South Korea, between January and July 2020. We randomized and assigned patients to the development and validation groups at a 70% to 30% ratio. Each point scored for selected risk factors helped build a new mortality scoring system using Cox regression analysis. We evaluated the accuracy of the new scoring system in the development and validation groups using the area under the curve. RESULTS: The development group included 1232 patients, whereas the validation group included 528 patients. In the development group, predictors for the new scoring system as selected by Cox proportional hazards model were age ≥70 years, diabetes, chronic kidney disease, dementia, C-reactive protein levels >4 mg/dL, infiltration on chest X-rays at the initial diagnosis, and the need for oxygen support on admission. The areas under the curve for the development and validation groups were 0.914 [95% confidence interval (CI) 0.891-0.937] and 0.898 (95% CI 0.854-0.941), respectively. According to our scoring system, COVID-19 mortality was 0.4% for the low-risk group (score 0-3) and 53.7% for the very high-risk group (score ≥11). CONCLUSION: We developed a new scoring system for quickly and easily predicting COVID-19 mortality using simple predictors. This scoring system can help physicians provide the proper therapy and strategy for each patient.

Significance and Associated Factors of Long-Term Sequelae in Patients after Acute COVID-19 Infection in Korea.

BACKGROUND: As the coronavirus disease 2019 (COVID-19) pandemic has progressed, there has been a growing awareness of the long-term impacts of the COVID-19 infection. However, until recently, there was no published study that investigated COVID-19-related sequelae and related factors for greater than six months from the onset of COVID-19 symptoms or the time of COVID-19 diagnosis in Korea. MATERIALS AND METHODS: Online survey and statistical analysis were conducted by Kyungpook National University Hospital on 5,252 patients diagnosed as COVID-19 between February 18, 2020 and March 14, 2020. Responders aged between 16 and 70 years were included. Long-term sequelae were defined as persistent symptoms or signs ≥ 6 months after acute COVID-19 infection. The survey was conducted from September 8, 2020 to September 10, 2020. Clinical characteristics and self-reported clinical sequelae of the responders were analyzed to investigate the prevalence and factors associated with sequelae using descriptive and multivariate logistic regression analysis. RESULTS: The median period from the date of the first symptom onset or COVID-19 diagnosis to the time of the survey was 195 (interquartile range [IQR] 191 - 200) days. The response rate was 17.1% (900 out of 5,252). The median age was 31 (IQR 24.0 - 47.0) years old, and 627 responders were female (69.7%). Regarding the disease severity, 29 (3.2%) were asymptomatic, 763 (84.8%) mild, 86 (9.6%) moderate, 17 (1.9%) severe, and 5 (0.6%) critical. In total, 591 (65.7%) responders suffered from COVID-19-related long-term sequelae and 78 (8.6%) responders were receiving outpatient treatment for COVID-19-related long-term sequelae. The most common symptoms identified during the isolation period were anosmia and ageusia at 44.5% and 43.5%, respectively. Fatigue was the most common long-term sequelae, accounting for 253 (26.2%) responders, followed by concentration difficulty, amnesia, cognitive dysfunction, anxiety, and depression, which accounted for over 20%. Female gender was identified as the factor associated with mental and psychological long-term sequelae (P <0.05). CONCLUSION: The results showed that the rate of COVID-19-related long-term sequelae was 65.7%. The most common long-term sequela was fatigue. The risk factor identified was female gender. It was found that the long-term sequelae had various manifestations, including mental and psychological aspects. To improve the care of COVID-19 recovered patients with COVID-19-related long-term sequelae, the participation of a comprehensive and an interdisciplinary group of researchers is required.

Neutralizing Antibody Responses to SARS-CoV-2 in Korean Patients Who Have Recovered from COVID-19.

PURPOSE: Neutralizing antibodies (NAbs) have been considered effective in preventing and treating viral infections. However, until now, the duration and clinical implications of antibody-mediated nature immunity in Koreans have remained unknown. Therefore, we examined NAbs levels and clinical characteristics in recovered coronavirus disease 2019 (COVID-19) patients. MATERIALS AND METHODS: Blood samples were collected from 143 adult patients who had been diagnosed with and had recovered from COVID-19 from February to March in 2020 at a tertiary-care university-affiliated hospital in Daegu, Korea. A plaque reduction neutralization test was conducted to analyze NAb titers. Individualized questionnaires were used to identify patient clinical information. RESULTS: The median number of days from symptom onset to the blood collection date was 109.0 (104.0; 115.0). The NAb titers ranged from 10 to 2560. The median NAb titer value was 40. Of the 143 patients, 68 (47.6%) patients had NAb titers ≥80, and 31 (21.7%) patients had NAb titers ≥160. The higher the age or disease severity, the higher the NAb titer. In univariate logistic regression, statistically significant predictors of high NAb titers (≥80) were age, myalgia, nausea or vomiting, dyspnea, and disease severity (p<0.05). Multivariable logistic regression showed that age ≥50 years (p=0.013) and moderate or higher disease severity (p<0.001) were factors associated with high NAb titers (≥80). None of the patients had reinfection of COVID-19. CONCLUSION: All recovered patients were found to have NAbs regardless of the NAb titers maintained by natural immunity. Age and disease severity during COVID-19 infection were associated with high NAb titers.

N-protein presents early in blood, dried blood and saliva during asymptomatic and symptomatic SARS-CoV-2 infection.

The COVID-19 pandemic continues to have an unprecedented impact on societies and economies worldwide. There remains an ongoing need for high-performance SARS-CoV-2 tests which may be broadly deployed for infection monitoring. Here we report a highly sensitive single molecule array (Simoa) immunoassay in development for detection of SARS-CoV-2 nucleocapsid protein (N-protein) in venous and capillary blood and saliva. In all matrices in the studies conducted to date we observe >98% negative percent agreement and >90% positive percent agreement with molecular testing for days 1-7 in symptomatic, asymptomatic, and pre-symptomatic PCR+ individuals. N-protein load decreases as anti-SARS-CoV-2 spike-IgG increases, and N-protein levels correlate with RT-PCR Ct-values in saliva, and between matched saliva and capillary blood samples. This Simoa SARS-CoV-2 N-protein assay effectively detects SARS-CoV-2 infection via measurement of antigen levels in blood or saliva, using non-invasive, swab-independent collection methods, offering potential for at home and point of care sample collection.

How to keep patients and staff safe from accidental SARS-CoV-2 exposure in the emergency room: Lessons from South Korea's explosive COVID-19 outbreak.

OBJECTIVES: We report our experience with an emergency room (ER) shutdown related to an accidental exposure to a patient with coronavirus disease 2019 (COVID-19) who had not been isolated. SETTING: A 635-bed, tertiary-care hospital in Daegu, South Korea. METHODS: To prevent nosocomial transmission of the disease, we subsequently isolated patients with suspected symptoms, relevant radiographic findings, or epidemiology. Severe acute respiratory coronavirus 2 (SARS-CoV-2) reverse-transcriptase polymerase chain reaction assays (RT-PCR) were performed for most patients requiring hospitalization. A universal mask policy and comprehensive use of personal protective equipment (PPE) were implemented. We analyzed effects of these interventions. RESULTS: From the pre-shutdown period (February 10-25, 2020) to the post-shutdown period (February 28 to March 16, 2020), the mean hourly turnaround time decreased from 23:31 ±6:43 hours to 9:27 ±3:41 hours (P < .001). As a result, the proportion of the patients tested increased from 5.8% (N=1,037) to 64.6% (N=690) (P < .001) and the average number of tests per day increased from 3.8±4.3 to 24.7±5.0 (P < .001). All 23 patients with COVID-19 in the post-shutdown period were isolated in the ER without any problematic accidental exposure or nosocomial transmission. After the shutdown, several metrics increased. The median duration of stay in the ER among hospitalized patients increased from 4:30 hours (interquartile range [IQR], 2:17-9:48) to 14:33 hours (IQR, 6:55-24:50) (P < .001). Rates of intensive care unit admissions increased from 1.4% to 2.9% (P = .023), and mortality increased from 0.9% to 3.0% (P = .001). CONCLUSIONS: Problematic accidental exposure and nosocomial transmission of COVID-19 can be successfully prevented through active isolation and surveillance policies and comprehensive PPE use despite longer ER stays and the presence of more severely ill patients during a severe COVID-19 outbreak.

Appendectomy in patient with suspected COVID-19 with negative COVID-19 results: A case report.

BACKGROUND: Even at present, we are in the middle of the novel coronavirus disease 2019 (COVID-19) pandemic and are facing challenges in trial and error. Presently, emergency surgery for patients with suspected COVID-19 is burdensome not only for patients but also for healthcare workers. Therefore, we established a surveillance system in the emergency room and established principles for managing patients suspected of COVID-19 who require emergency surgery. CASE SUMMARY: A 67-year-old man was diagnosed with appendicitis in March 2020. His wife was diagnosed with COVID-19 10 d earlier, and the patient was in close contact with her. The patient tested negative twice on an upper respiratory COVID-19 reverse transcription-polymerase chain reaction screening test, but chest X-ray and chest computed tomography revealed patchy ground-glass opacity in both upper lobes of the patient's lungs. The same emergency surgery procedure for patients with confirmed COVID-19 was applied to this patient suspected of having the disease to ensure that surgery was not delayed while waiting for the reverse transcription-polymerase chain reaction results. A few hours after surgery, the upper respiratory tract specimen taken in the emergency room was negative for COVID-19 but the lower respiratory tract specimen was found to be positive for the disease. CONCLUSION: When COVID-19 is suspected, emergency surgery should be performed as for confirmed COVID-19 without delay.