Characterisation of the pro-inflammatory cytokine signature in severe COVID-19.

Clinical outcomes from infection with SARS-CoV-2, the cause of the COVID-19 pandemic, are remarkably variable ranging from asymptomatic infection to severe pneumonia and death. One of the key drivers of this variability is differing trajectories in the immune response to SARS-CoV-2 infection. Many studies have noted markedly elevated cytokine levels in severe COVID-19, although results vary by cohort, cytokine studied and sensitivity of assay used. We assessed the immune response in acute COVID-19 by measuring 20 inflammatory markers in 118 unvaccinated patients with acute COVID-19 (median age: 70, IQR: 58-79 years; 48.3% female) recruited during the first year of the pandemic and 44 SARS-CoV-2 naïve healthy controls. Acute COVID-19 was associated with marked elevations in nearly all pro-inflammatory markers, whilst eleven markers (namely IL-1ß, IL-2, IL-6, IL-10, IL-18, IL-23, IL-33, TNF-α, IP-10, G-CSF and YKL-40) were associated with disease severity. We observed significant correlations between nearly all markers elevated in those infected with SARS-CoV-2 consistent with widespread immune dysregulation. Principal component analysis highlighted a pro-inflammatory cytokine signature (with strongest contributions from IL-1ß, IL-2, IL-6, IL-10, IL-33, G-CSF, TNF-α and IP-10) which was independently associated with severe COVID-19 (aOR: 1.40, 1.11-1.76, p=0.005), invasive mechanical ventilation (aOR: 1.61, 1.19-2.20, p=0.001) and mortality (aOR 1.57, 1.06-2.32, p = 0.02). Our findings demonstrate elevated cytokines and widespread immune dysregulation in severe COVID-19, adding further evidence for the role of a pro-inflammatory cytokine signature in severe and critical COVID-19.

Conceptualizing the Episodic Nature of Disability among Adults Living With Long COVID: Qualitative Study...American Congress of Rehabilitation Medicine (ACRM) 99th Annual Conference, November 8-11, 2022, Chicago, Illinois

To describe experiences of disability among adults living with Long COVID. We conducted a community-engaged qualitative descriptive study involving online semi-structured interviews. We recruited participants via collaborator community networks in Canada, United Kingdom, United States and Ireland. Adults who self-identified as living with Long COVID, defined as signs and symptoms that develop during or following an infection consistent with COVID-19, which continue for 12-weeks or more and not explained by an alternative diagnosis. We purposively recruited for diversity in country, gender, age, sexual orientation, and duration since initial COVID-19 infection. Not applicable. We used a semi-structured interview guide to explore experiences of disability living with Long COVID, specifically health-related challenges and how they were experienced over time. We asked participants to draw their health trajectory. We conducted a group-based content analysis. Among the 40 participants (10 per country), the median age was 39 years;majority were women (63%), white (73%), heterosexual (75%), and living with Long COVID for ≥1 year (83%). Participants described their disability experiences as episodic in nature, characterized by fluctuations in presence and severity of health-related challenges (disability) that may occur within the day to over the long-term living with Long COVID. They described living with 'ups and downs', 'flare-ups', and 'peaks' followed by 'crashes', 'troughs', and 'valleys', likened to a 'yo-yo' 'rolling hills', and 'rollercoaster ride' with 'relapsing/remitting', 'waxing/waning', 'fluctuations' in health. Illustrations demonstrated trajectories of health dimensions, some more episodic than others. Uncertainty intersected with the episodic nature of disability, characterized as unpredictability of episodes, their length, severity and triggers, and process of long-term recovery, which had implications on broader health. Experiences of disability were described as episodic in nature, characterized by fluctuating health challenges, which may be unpredictable among this sample of adults living with Long COVID. Results will help to better understand experiences of disability among adults living with Long COVID and inform approaches for rehabilitation. None.

Conceptualizing the Episodic Nature of Disability among Adults Living With Long COVID: Qualitative Study

To describe experiences of disability among adults living with Long COVID. We conducted a community-engaged qualitative descriptive study involving online semi-structured interviews. We recruited participants via collaborator community networks in Canada, United Kingdom, United States and Ireland. Adults who self-identified as living with Long COVID, defined as signs and symptoms that develop during or following an infection consistent with COVID-19, which continue for 12-weeks or more and not explained by an alternative diagnosis. We purposively recruited for diversity in country, gender, age, sexual orientation, and duration since initial COVID-19 infection. Not applicable. We used a semi-structured interview guide to explore experiences of disability living with Long COVID, specifically health-related challenges and how they were experienced over time. We asked participants to draw their health trajectory. We conducted a group-based content analysis. Among the 40 participants (10 per country), the median age was 39 years;majority were women (63%), white (73%), heterosexual (75%), and living with Long COVID for ≥1 year (83%). Participants described their disability experiences as episodic in nature, characterized by fluctuations in presence and severity of health-related challenges (disability) that may occur within the day to over the long-term living with Long COVID. They described living with 'ups and downs', 'flare-ups', and 'peaks' followed by 'crashes', 'troughs', and 'valleys', likened to a 'yo-yo' 'rolling hills', and 'rollercoaster ride' with 'relapsing/remitting', 'waxing/waning', 'fluctuations' in health. Illustrations demonstrated trajectories of health dimensions, some more episodic than others. Uncertainty intersected with the episodic nature of disability, characterized as unpredictability of episodes, their length, severity and triggers, and process of long-term recovery, which had implications on broader health. Experiences of disability were described as episodic in nature, characterized by fluctuating health challenges, which may be unpredictable among this sample of adults living with Long COVID. Results will help to better understand experiences of disability among adults living with Long COVID and inform approaches for rehabilitation. None.

Conceptualising the episodic nature of disability among adults living with Long COVID: a qualitative study.

INTRODUCTION: Our aim was to describe episodic nature of disability among adults living with Long COVID. METHODS: We conducted a community-engaged qualitative descriptive study involving online semistructured interviews and participant visual illustrations. We recruited participants via collaborator community organisations in Canada, Ireland, UK and USA.We recruited adults who self-identified as living with Long COVID with diversity in age, gender, race/ethnicity, sexual orientation and duration since initial COVID infection between December 2021 and May 2022. We used a semistructured interview guide to explore experiences of disability living with Long COVID, specifically health-related challenges and how they were experienced over time. We asked participants to draw their health trajectory and conducted a group-based content analysis. RESULTS: Among the 40 participants, the median age was 39 years (IQR: 32-49); majority were women (63%), white (73%), heterosexual (75%) and living with Long COVID for ≥1 year (83%). Participants described their disability experiences as episodic in nature, characterised by fluctuations in presence and severity of health-related challenges (disability) that may occur both within a day and over the long-term living with Long COVID. They described living with 'ups and downs', 'flare-ups' and 'peaks' followed by 'crashes', 'troughs' and 'valleys', likened to a 'yo-yo', 'rolling hills' and 'rollercoaster ride' with 'relapsing/remitting', 'waxing/waning', 'fluctuations' in health. Drawn illustrations demonstrated variety of trajectories across health dimensions, some more episodic than others. Uncertainty intersected with the episodic nature of disability, characterised as unpredictability of episodes, their length, severity and triggers, and process of long-term trajectory, which had implications on broader health. CONCLUSION: Among this sample of adults living with Long COVID, experiences of disability were described as episodic, characterised by fluctuating health challenges, which may be unpredictable in nature. Results can help to better understand experiences of disability among adults living with Long COVID to inform healthcare and rehabilitation.

SARS-CoV-2 epidemiology, antibody dynamics, and neutralisation capacity in Irish healthcare workers in the era of booster COVID-19 vaccinations.

Background: The PRECISE Study, a multi-phase cross-sectional seroprevalence study of anti-SARS-CoV-2 antibodies in Irish healthcare workers (HCW) investigated: (1) risk factors for SARS-CoV-2 seropositivity, (2) the durability of antibody responses in a highly vaccinated HCW cohort, and (3) the neutralisation capacity of detected antibodies, prior to booster COVID-19 vaccination. Materials and methods: Serology samples were collected across two hospital sites in November 2021 and analysed using the Roche Elecsys Anti-SARS-CoV-2/Elecsys-S Anti-SARS-CoV-2 assays to detect anti-nucleocapsid (N) and anti-spike (S) antibodies respectively. Paired serology results from prior study phases were used to analyse changes in individual HCW serostatus over time. Risk-factors for SARS-CoV-2 infection were assessed for demographic and work-related factors. Antibody neutralisation capacity was assessed in a subset of samples via an in vitro ACE2 binding enzyme-linked immunosorbent assay. Results: 2,344 HCW samples were analysed. Median age was 43 years (IQR 33-50) with 80.5% (n = 1,886) female participants. Irish (78.9%, n = 1,850) and Asian (12.3%, n = 288) were the most commonly reported ethnicities. Nursing/midwifery (39.3%, n = 922) was the most common job role. 97.7% of participants were fully vaccinated, with Pfizer (81.1%, n = 1,902) and AstraZeneca (16.1%, n = 377) the most common vaccines received. Seroprevalence for anti-SARS-CoV-2 antibodies indicating prior infection was 23.4%, of these 33.6% represented previously undiagnosed infections. All vaccinated participants demonstrated positive anti-S antibodies and in those with paired serology, no individual demonstrated loss of previously positive anti-S status below assay threshold for positivity. Interval loss of anti-N antibody positivity was demonstrated in 8.8% of previously positive participants with paired results. Risk factors for SARS-CoV-2 seropositivity suggestive of previous infection included age 18-29 years (aRR 1.50, 95% CI 1.19-1.90, p < 0.001), India as country of birth (aRR 1.35, 95% CI 1.01-1.73, p = 0.036), lower education level (aRR 1.35, 95% CI 1.11-1.66, p = 0.004) and HCA job role (aRR 2.12, 95% CI 1.51-2.95, p < 0.001). Antibody neutralisation varied significantly by anti-SARS-CoV-2 antibody status, with highest levels noted in those anti-N positive, in particular those with vaccination plus previous SARS-CoV-2 infection. Conclusion: All vaccinated HCWs maintained anti-S positivity prior to COVID-19 booster vaccination, however anti-N positivity was more dynamic over time. Antibody neutralisation capacity was highest in participants with COVID-19 vaccination plus prior SARS-CoV-2 infection.

Endothelial cell activation, Weibel-Palade body secretion, and enhanced angiogenesis in severe COVID-19.

Background: Severe COVID-19 is associated with marked endothelial cell (EC) activation that plays a key role in immunothrombosis and pulmonary microvascular occlusion. However, the biological mechanisms through which SARS-CoV-2 causes EC activation and damage remain poorly defined. Objectives: We investigated EC activation in patients with acute COVID-19, and specifically focused on how proteins stored within Weibel-Palade bodies may impact key aspects of disease pathogenesis. Methods: Thirty-nine patients with confirmed COVID-19 were recruited. Weibel-Palade body biomarkers (von Willebrand factor [VWF], angiopoietin-2 [Angpt-2], and osteoprotegerin) and soluble thrombomodulin (sTM) levels were determined. In addition, EC activation and angiogenesis were assessed in the presence or absence of COVID-19 plasma incubation. Results: Markedly elevated plasma VWF antigen, Angpt-2, osteoprotegerin, and sTM levels were observed in patients with acute COVID-19. The increased levels of both sTM and Weibel-Palade body components (VWF, osteoprotegerin, and Angpt-2) correlated with COVID-19 severity. Incubation of COVID-19 plasma with ECs triggered enhanced VWF secretion and increased Angpt-2 expression, as well as significantly enhanced in vitro EC tube formation and angiogenesis. Conclusion: We propose that acute SARS-CoV-2 infection leads to a complex and multifactorial EC activation, progressive loss of thrombomodulin, and increased Angpt-2 expression, which collectively serve to promote a local proangiogenic state.

Risk factors and outcomes of delirium in hospitalized older adults with COVID-19: a systematic review and meta-analysis

Background Older adults with COVID-19 are more likely to present with atypical symptoms, notably delirium. The main objective of this meta-analysis is to identify risk factors for delirium and outcomes of delirium in hospitalized older adults (65 years or above) with COVID-19. Methods Comprehensive literature search of Embase, CINAHIL, Medline and Web of Science was performed for published literature until 31st August 2021. Two independent researchers evaluated study eligibility and assessed study quality using the Newcastle Ottawa Scale (NOS) for cohort studies and Joanna Briggs Institute (JBI) critical appraisal tools for case series. The association of various predisposing factors with delirium in this cohort was reported as odds ratio (OR) and its 95% confidence interval (CI). Results A total of 31 studies from 11 countries were included in this review. Most of the included studies investigated patients from non-ICU settings (n=24;77.4%). Frailty (OR 3.52, 95% CI: 1.96-6.31, p<0.0001, I2=71.63%), cognitive impairment including dementia (OR 6.17, 95% CI: 2.92-13.07, p<0.00001, I2=88.63%) and being nursing home residents (OR 1.72, 95% CI: 1.31-2.24, p<0.0001, I2=0) were significantly associated with increased likelihood of developing delirium in older adults with COVID-19. The presence of delirium also significantly increases mortality risk in hospitalized older adults with COVID-19 (OR 2.51, 95% CI: 1.51-4.17, p<0.0001, I2=89.3%). Conclusion Our review identifies key factors associated with increased risk of developing delirium in hospitalized older adults with COVID-19. Identification of patients at risk of delirium and attention to these factors early during admission may improve outcomes for this vulnerable cohort.

Risk factors and outcomes of delirium in hospitalized older adults with COVID-19: A systematic review and meta-analysis.

Background: Older adults with COVID-19 are more likely to present with atypical symptoms, notably delirium. The main objective of this meta-analysis is to identify risk factors for delirium and outcomes of delirium in hospitalized older adults (65 years or above) with COVID-19. Methods: Comprehensive literature search of Embase, CINAHIL, Medline and Web of Science was performed for published literature until 31st August 2021. Two independent researchers evaluated study eligibility and assessed study quality using the Newcastle Ottawa Scale (NOS) for cohort studies and Joanna Briggs Institute (JBI) critical appraisal tools for case series. The association of various predisposing factors with delirium in this cohort was reported as odds ratio (OR) and its 95% confidence interval (CI). Results: A total of 31 studies from 11 countries were included in this review. Most of the included studies investigated patients from non-ICU settings (n = 24; 77.4%). Frailty (OR 3.52, 95% CI: 1.96-6.31, p<0.0001, I2=71.63%), cognitive impairment including dementia (OR 6.17, 95% CI: 2.92-13.07, p<0.00001, I2=88.63%) and being nursing home residents (OR 1.72, 95% CI: 1.31-2.24, p<0.0001, I2=0) were significantly associated with increased likelihood of developing delirium in older adults with COVID-19. The presence of delirium also significantly increases mortality risk in hospitalized older adults with COVID-19 (OR 2.51, 95% CI: 1.51-4.17, p<0.0001, I2=89.3%). Conclusion: Our review identifies key factors associated with increased risk of developing delirium in hospitalized older adults with COVID-19. Identification of patients at risk of delirium and attention to these factors early during admission may improve outcomes for this vulnerable cohort.

Study protocol for the St James's Hospital, Tallaght University Hospital, Trinity College Dublin Allied Researchers' (STTAR) Bioresource for COVID-19.

Background: The current coronavirus disease 2019 (COVID-19) pandemic began in Ireland with the first confirmed positive case in March 2020. In the early stages of the pandemic clinicians and researchers in two affiliated Dublin hospitals identified the need for a COVID-19 biobanking initiative to support and enhance research into the disease. Through large scale analysis of clinical, regional, and genetic characteristics of COVID-19 patients, biobanks have helped identify, and so protect, at risk patient groups The STTAR Bioresource has been created to collect and store data and linked biological samples from patients with SARS-CoV-2 infection and healthy and disease controls. Aim: The primary objective of this study is to build a biobank, to understand the clinical characteristics and natural history of COVID-19 infection with the long-term goal of research into improved disease understanding, diagnostic tests and treatments. Methods: This is a prospective dual-site cohort study across two tertiary acute university teaching hospitals. Patients are recruited from inpatient wards or outpatient clinics. Patients with confirmed COVID-19 infection as well as healthy and specific disease control groups are recruited.  Biological samples are collected and a case report form detailing demographic and medical background is entered into the bespoke secure online Dendrite database. Impact: The results of this study will be used to inform national and international strategy on health service provision and disease management related to COVID-19. In common with other biobanks, study end points  evolve over time as new research questions emerge. They currently include patient survival, occurrence of severe complications of the disease or its therapy, occurrence of persistent symptoms following recovery from the acute illness and vaccine responses.

Severe COVID-19 is characterised by inflammation and immature myeloid cells early in disease progression.

SARS-CoV-2 infection causes a wide spectrum of disease severity. Identifying the immunological characteristics of severe disease and the risk factors for their development are important in the management of COVID-19. This study aimed to identify and rank clinical and immunological features associated with progression to severe COVID-19 in order to investigate an immunological signature of severe disease. One hundred and eight patients with positive SARS-CoV-2 PCR were recruited. Routine clinical and laboratory markers were measured, as well as myeloid and lymphoid whole-blood immunophenotyping and measurement of the pro-inflammatory cytokines IL-6 and soluble CD25. All analysis was carried out in a routine hospital diagnostic laboratory. Univariate analysis demonstrated that severe disease was most strongly associated with elevated CRP and IL-6, loss of DLA-DR expression on monocytes and CD10 expression on neutrophils. Unbiased machine learning demonstrated that these four features were strongly associated with severe disease, with an average prediction score for severe disease of 0.925. These results demonstrate that these four markers could be used to identify patients developing severe COVID-19 and allow timely delivery of therapeutics.

Long COVID and episodic disability: advancing the conceptualisation, measurement and knowledge of episodic disability among people living with Long COVID - protocol for a mixed-methods study.

INTRODUCTION: As the prevalence of Long COVID increases, there is a critical need for a comprehensive assessment of disability. Our aims are to: (1) characterise disability experiences among people living with Long COVID in Canada, UK, USA and Ireland; and (2) develop a patient-reported outcome measure to assess the presence, severity and episodic nature of disability with Long COVID. METHODS AND ANALYSIS: In phase 1, we will conduct semistructured interviews with adults living with Long COVID to explore experiences of disability (dimensions, uncertainty, trajectories, influencing contextual factors) and establish an episodic disability (ED) framework in the context of Long COVID (n~10 each country). Using the conceptual framework, we will establish the Long COVID Episodic Disability Questionnaire (EDQ). In phase 2, we will examine the validity (construct, structural) and reliability (internal consistency, test-retest) of the EDQ for use in Long COVID. We will electronically administer the EDQ and four health status criterion measures with adults living with Long COVID, and readminister the EDQ 1 week later (n~170 each country). We will use Rasch analysis to refine the EDQ, and confirm structural and cross-cultural validity. We will calculate Cronbach's alphas (internal consistency reliability), and intraclass correlation coefficients (test-retest reliability), and examine correlations for hypotheses theorising relationships between EDQ and criterion measure scores (construct validity). Using phase 2 data, we will characterise the profile of disability using structural equation modelling techniques to examine relationships between dimensions of disability and the influence of intrinsic and extrinsic contextual factors. This research involves an academic-clinical-community partnership building on foundational work in ED measurement, Long COVID and rehabilitation. ETHICS AND DISSEMINATION: This study was approved by the University of Toronto Research Ethics Board. Knowledge translation will occur with community collaborators in the form of presentations and publications in open access peer-reviewed journals and presentations.

Prevalence of Antibodies to SARS-CoV-2 Following Natural Infection and Vaccination in Irish Hospital Healthcare Workers: Changing Epidemiology as the Pandemic Progresses.

BACKGROUND: In October 2020 SARS-CoV-2 seroprevalence among hospital healthcare workers (HCW) of two Irish hospitals was 15 and 4. 1%, respectively. We compare seroprevalence in the same HCW population 6 months later, assess changes in risk factors for seropositivity with progression of the pandemic and serological response to vaccination. METHODS: All staff of both hospitals (N = 9,038) were invited to participate in an online questionnaire and SARS-CoV-2 antibody testing in April 2021. We measured anti-nucleocapsid and anti-spike antibodies. Frequencies and percentages for positive SARS-CoV-2 antibodies were calculated and adjusted relative risks for participant characteristics were calculated using multivariable regression analysis. RESULTS: Five thousand and eighty-five HCW participated. Seroprevalence increased to 21 and 13%, respectively; 26% of infections were previously undiagnosed. Black ethnicity (aRR 1.7, 95% CI 1.3-2.2, p < 0.001), lower level of education (aRR 1.4 for secondary level education, 95% CI 1.1-1.8, p = 0.002), living with other HCW (aRR 1.2, 95% CI 1.0-1.4, p = 0.007) were significantly associated with seropositivity. Having direct patient contact also carried a significant risk being a healthcare assistant (aRR 1.8, 95% CI 1.3-2.3, p < 0.001), being a nurse (aRR 1.4, 95% CI 1.0-1.8, p = 0.022), daily contact with COVID-19 patients (aRR 1.4, 95% CI 1.1-1.7, p = 0.002), daily contact with patients without suspected or confirmed COVID-19 (aRR 1.3, 95% CI 1.1-1.5, p = 0.013). Breakthrough infection occurred in 23/4,111(0.6%) of fully vaccinated participants; all had anti-S antibodies. CONCLUSION: The increase in seroprevalence reflects the magnitude of the third wave of the pandemic in Ireland. Genomic sequencing is needed to apportion risk to the workplace vs. the household/community. Concerted efforts are needed to mitigate risk factors due to ethnicity and lower level of education, even at this stage of the pandemic. The undiagnosed and breakthrough infections call for ongoing infection prevention and control measures and testing of HCW in the setting of close contact. Vaccinated HCW with confirmed infection should be actively assessed, including SARS-CoV-2 whole genome sequencing (WGS), serology testing and assessment of host determinants, to advance understanding of the reasons for breakthrough infection.

Disability and self-care living strategies among adults living with HIV during the COVID-19 pandemic.

BACKGROUND: Events associated with the COVID-19 pandemic, such as physical distancing, closure of community services, postponement of health appointments, and loss of employment can lead to social isolation, financial uncertainty, and interruption of antiretroviral adherence, resulting in additional health-related challenges (disability) experienced among adults living with chronic illness such as HIV. 'Living strategies' is a concept derived from the perspectives of people living with HIV, defined as behaviors, attitudes and beliefs adopted by people living with HIV to help deal with disability associated with HIV and multi-morbidity. Our aim was to describe disability among adults living with HIV and self-care living strategies used during the COVID-19 pandemic. METHODS: Adults living with HIV in Toronto, Ontario, Canada, including some with pre-pandemic HIV Disability Questionnaire (HDQ) data, completed a cross-sectional web-based survey between June-August 2020. The survey included the HDQ and questions about self-care living strategy use during the pandemic. We compared disability (HDQ) scores prior to versus during the pandemic using paired t-tests. We reported the proportion of participants who engaged in various living strategies at least 'a few times a week' or 'everyday' during the pandemic. RESULTS: Of the 63 respondents, 84% were men, median age 57 years, and 62% lived alone. During the pandemic the greatest disability severity was in the uncertainty [median 30; Interquartile range (IQR): 16, 43] and mental-emotional (25; IQR: 14, 41) domains. Among the 51 participants with pre-pandemic data, HDQ severity scores were significantly greater (worse) during the pandemic (vs prior) in all domains. Greatest change from prior to during the pandemic was in the mental-emotional domain for presence (17.7; p < 0.001), severity (11.4; p < 0.001), and episodic nature (9.3; p < 0.05) of disability. Most participants (> 60%) reported engaging a 'few times a week' or 'everyday' in self-care strategies associated with maintaining sense of control and adopting positive attitudes and beliefs. CONCLUSIONS: People living with HIV reported high levels of uncertainty and mental-emotional health challenges during the pandemic. Disability increased across all HDQ dimensions, with the greatest worsening in the mental-emotional health domain. Results provide an understanding of disability and self-care strategy use during the COVID-19 pandemic.

Acceptability of and symptom findings from an online symptom check-in tool for COVID-19 outpatient follow-up among a predominantly healthcare worker population.

INTRODUCTION: Health systems worldwide have had to prepare for a surge in volume in both the outpatient and inpatient settings since the emergence of COVID-19. Early international healthcare experiences showed approximately 80% of patients with COVID-19 had mild disease and therfore could be managed as outpatients. However, SARS-CoV-2 can cause a biphasic illness with those affected experiencing a clinical deterioration usually seen after day 4 of illness. OBJECTIVE: We created an online tool with the primary objective of allowing for virtual disease triage among the increasing number of outpatients diagnosed with COVID-19 at our hospital. Secondary aims included COVID-19 education and the promotion of official COVID-19 information among these outpatients, and analysis of reported symptomatology. METHODS: Outpatients with acute COVID-19 disease received text messages from the hospital containing a link to an online symptom check-in tool which they were invited to complete. RESULTS: 296 unique participants (72%) from 413 contacted by text completed the online check-in tool at least once, generating 831 responses from 1324 texts sent. 83% of text recipients and 91% of unique participants were healthcare workers. 7% of responses to the tool were from participants who admitted to a slight worsening of their symptoms during follow-up. Fatigue was the most commonly reported symptom overall (79%), followed by headache (72%). Fatigue, headache and myalgia were the most frequently reported symptoms in the first 3 days of illness. 8% of responses generated in the first 7 days of illness did not report any of the cardinal symptoms (fever, cough, dyspnoea, taste/smell disturbance) of COVID-19. Participants found the tool to be useful and easy to use, describing it as 'helpful' and 'reassuring' in a follow-up feedback survey (n=140). 93% said they would use such a tool in the future. 39% reported ongoing fatigue, 16% reported ongoing smell disturbance and 14% reported ongoing dyspnoea after 6 months. CONCLUSION: The online symptom check-in tool was found to be acceptable to participants and saw high levels of engagement and satisfaction. Symptomatology findings highlight the variety and persistence of symptoms experienced by those with confirmed COVID-19 disease.

SARS-CoV-2 Antibody Testing in Health Care Workers: A Comparison of the Clinical Performance of Three Commercially Available Antibody Assays.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies are an excellent indicator of past COVID-19 infection. As the COVID-19 pandemic progresses, retained sensitivity over time is an important quality in an antibody assay that is to be used for the purpose of population seroprevalence studies. We compared 5,788 health care worker (HCW) serum samples by using two serological assays (Abbott SARS-CoV-2 anti-nucleocapsid immunoglobulin G (IgG) and Roche anti-SARS-CoV-2 anti-nucleocapsid total antibody) and a subset of samples (all Abbott assay positive or grayzone, n = 485) on Wantai SARS-CoV-2 anti-spike antibody enzyme-linked immunosorbent assay (ELISA). For 367 samples from HCW with a previous PCR-confirmed SARS-CoV-2 infection, we correlated the timing of infection with assay results. Overall, seroprevalence was 4.2% on Abbott and 9.5% on Roche. Of those with previously confirmed infection, 41% (150/367) and 95% (348/367) tested positive on Abbott and Roche, respectively. At 21 weeks (150 days) after confirmed infection, positivity on Abbott started to decline. Roche positivity was retained for the entire study period (33 weeks). Factors associated (P ≤ 0.050) with Abbott seronegativity in those with previous PCR-confirmed infection included sex (odds ratio [OR], 0.30 male ; 95% confidence interval [CI], 0.15 to 0.60), symptom severity (OR 0.19 severe symptoms; 95% CI, 0.05 to 0.61), ethnicity (OR, 0.28 Asian ethnicity; 95% CI, 0.12 to 0.60), and time since PCR diagnosis (OR, 2.06 for infection 6 months previously; 95% CI, 1.01 to 4.30). Wantai detected all previously confirmed infections. In our population, Roche detected antibodies up to at least 7 months after natural infection with SARS-CoV-2. This finding indicates that the Roche total antibody assay is better suited than Abbott IgG assay to population-based studies. Wantai demonstrated high sensitivity, but sample selection was biased. The relationship between serological response and functional immunity to SARS-CoV-2 infection needs to be delineated. IMPORTANCE As the COVID-19 pandemic progresses, retained sensitivity over time is an important quality in an antibody assay that is to be used for the purpose of population seroprevalence studies. There is a relative paucity of published literature in this field to help guide public health specialists when planning seroprevalence studies. In this study, we compared results of 5,788 health care worker blood samples tested by using two assays (Roche and Elecsys, anti-nucleocapsid antibody) and by testing a subset on a third assay (Wantai enzyme-linked immunosorbent assay [ELISA] anti-spike antibody). We found significant differences in the performance of these assays, especially with distance in time from PCR-confirmed COVID-19 infection, and we feel these results may significantly impact the choice of assay for others conducting similar studies.

Persistent endotheliopathy in the pathogenesis of long COVID syndrome.

BACKGROUND: Persistent symptoms including breathlessness, fatigue, and decreased exercise tolerance have been reported in patients after acute SARS-CoV-2 infection. The biological mechanisms underlying this "long COVID" syndrome remain unknown. However, autopsy studies have highlighted the key roles played by pulmonary endotheliopathy and microvascular immunothrombosis in acute COVID-19. OBJECTIVES: To assess whether endothelial cell activation may be sustained in convalescent COVID-19 patients and contribute to long COVID pathogenesis. PATIENTS AND METHODS: Fifty patients were reviewed at a median of 68 days following SARS-CoV-2 infection. In addition to clinical workup, acute phase markers, endothelial cell (EC) activation and NETosis parameters and thrombin generation were assessed. RESULTS: Thrombin generation assays revealed significantly shorter lag times (p < .0001, 95% CI -2.57 to -1.02 min), increased endogenous thrombin potential (p = .04, 95% CI 15-416 nM/min), and peak thrombin (p < .0001, 95% CI 39-93 nM) in convalescent COVID-19 patients. These prothrombotic changes were independent of ongoing acute phase response or active NETosis. Importantly, EC biomarkers including von Willebrand factor antigen (VWF:Ag), VWF propeptide (VWFpp), and factor VIII were significantly elevated in convalescent COVID-19 compared with controls (p = .004, 95% CI 0.09-0.57 IU/ml; p = .009, 95% CI 0.06-0.5 IU/ml; p = .04, 95% CI 0.03-0.44 IU/ml, respectively). In addition, plasma soluble thrombomodulin levels were significantly elevated in convalescent COVID-19 (p = .02, 95% CI 0.01-2.7 ng/ml). Sustained endotheliopathy was more frequent in older, comorbid patients, and those requiring hospitalization. Finally, both plasma VWF:Ag and VWFpp levels correlated inversely with 6-min walk tests. CONCLUSIONS: Collectively, our findings demonstrate that sustained endotheliopathy is common in convalescent COVID-19 and raise the intriguing possibility that this may contribute to long COVID pathogenesis.

SARS-CoV-2 anti-nucleocapsid assay performance in healthcare workers at baseline and 6 months.

INTRODUCTION: Serological SARS-CoV-2 assays have an important role in guiding the pandemic response. This research aimed to compare the performance of 2 antinucleocapsid assays. METHODS: Serum from 49 HCWs was analysed at baseline and 6 months using the Abbott diagnostics SARS-CoV-2 IgG assay and the Roche Diagnostics Elecsys Anti-SARS-CoV-2 total antibody assay. RESULTS: At baseline, 14/49 participants (29%) demonstrated antibody reactivity using the Abbott assay. At 6 months, 4/14 participants (29%) continued to demonstrate reactivity. A total of 14/49 (29%) participants had detectable antibodies at baseline using the Roche assay. In total, 13/14 (93%) of participants demonstrated antibody reactivity at 6 months. The Abbott assay showed a statistically significant difference in the signal-to-threshold values of baseline reactive samples when repeated at 6 months (p = 0.001). This was not seen with the Roche assay (p = 0.51). CONCLUSION: In this small study, the Roche Diagnostics Elecsys Anti-SARS-CoV-2 total antibody assay appears superior in performance to the Abbott diagnostics SARS-CoV-2 IgG assay in accurately detecting participants with a history of confirmed COVID-19 disease at 6 months follow-up. This finding should be born in mind in the planning of future seroprevalence studies, especially when considering the use of anti-nucleocapsid assays.

Dynamic Assay for Profiling Anti-SARS-CoV-2 Antibodies and Their ACE2/Spike RBD Neutralization Capacity.

Serological assays have been widely employed during the coronavirus disease 2019 (COVID-19) pandemic to measure antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and to track seroconversion in populations. However, currently available assays do not allow determination of neutralization capacity within the assay protocol. Furthermore, commercial serology assays have a high buy-in cost that is inaccessible for many research groups. We have replicated the serological enzyme-linked immunosorbent assay for the detection of SARS-CoV-2 antibody isotypes, developed at the Icahn School of Medicine at Mount Sinai, New York. Additionally, we have modified the protocol to include a neutralization assay with only a minor modification to this protocol. We used this assay to screen local COVID-19 patient sera (n = 91) and pre-COVID-19 control sera (n = 103), and obtained approximate parity with approved commercial anti-nucleoprotein-based assays with these sera. Furthermore, data from our neutralization assay closely aligns with that generated using a spike-based pseudovirus infection model when a subset of patient sera was analyzed.

Erratum to: Bacterial pneumonia coinfection and antimicrobial therapy duration in SARS-CoV-2 (COVID-19) infection.

[This corrects the article DOI: 10.1093/jacamr/dlaa071.].