Longitudinal wastewater surveillance addressed public health priorities during the transition from "dynamic COVID-zero" to "opening up" in China: a population-based study (preprint)

Background Wastewater surveillance provides real-time, cost-effective monitoring of SARS-CoV-2 transmission. We developed the first city-level wastewater warning system in mainland China, located in Shenzhen. Our study aimed to reveal cryptic transmissions under the "dynamic COVID-zero" policy and characterize the dynamics of the infected population and variant prevalence, and then guide the allocation of medical resources during the transition to "opening up" in China. Methods In this population-based study, a total of 1,204 COVID-19 cases were enrolled to evaluate the contribution of Omicron variant-specific faecal shedding rates in wastewater. After that, wastewater samples from up to 334 sites distributed in communities and port areas in two districts of Shenzhen covering 1.74 million people were tested daily to evaluate the sensitivity and specificity of this approach and were validated against daily SARS-CoV-2 screening. After the public health policy was switched to "opening up" in December 7, 2022, we conducted wastewater surveillance at wastewater treatment plants and pump stations covering 3.55 million people to estimate infected populations using model prediction and detect the relative abundance of SARS-CoV-2 lineages using wastewater sequencing. Findings In total, 82.4% of SARS-CoV-2 Omicron cases tested positive for faecal viral RNA within the first four days after the diagnosis, which was far more than the proportion of the ancestral variant. A total of 27,759 wastewater samples were detected from July 26 to November 30 in 2022, showing a sensitivity of 73.8% and a specificity of 99.8%. We further found that wastewater surveillance played roles in providing early warnings and revealing cryptic transmissions in two communities. Based on the above results, we employed a prediction model to monitor the daily number of infected individuals in Shenzhen during the transition to "opening up" in China, with over 80% of the population infected in both Futian District and Nanshan District. Notably, the prediction of the daily number of hospital admission was consistent with the actual number. Further sequencing revealed that the Omicron subvariant BA.5.2.48 accounted for the most abundant SARS-CoV-2 RNA in wastewater, and BF.7.14 and BA.5.2.49 ranked second and third, respectively, which was consistent with the clinical sequencing. Interpretation This study provides a scalable solution for wastewater surveillance of SARS-CoV-2 to provide real-time monitoring of the new variants, infected populations and facilitate the precise prediction of hospital admission. This novel framework could be a One Health system for the surveillance of other infectious and emerging pathogens with faecal shedding and antibiotic resistance genes in the future. Funding Sanming Project of Medicine in Shenzhen, Shenzhen Key Medical Discipline Construction Fund.

Adaptation and Validation of the COVID-19 Stigma Instrument in Nurses:A Cross-sectional Survey (preprint)

Background: Stigma is a prominent issue among nurses working with patients with infectious diseases, but the unavailability of validated measures of such stigma. The aim of our study was to adapt, modify, and validate the COVID-19 Stigma Instrument-Nurse -Version 3 (CSI-N-3) with both classical test theory and item response theory (IRT) analysis.Methods: We administered the scale to 249 eligible nurses who worked in a COVID-19 designed hospital in Shanghai, China. Results: The two-factor structure was confirmed by confirmatory factor analysis. The 15-item CSI-N-3 achieved Cronbach's α of 0.64 to 0.84. Convergent validity was also demonstrated. In IRT analysis, the CSI-N-3 has ordered response thresholds, with the appropriate item difficulty and infit and outfit mean squares. Self-reported social support was the only factor influencing nurses' COVID-19 stigma (standardized coefficients β=-0.21). Conclusions: The CSI-N-3 is an instrument with sound psychometric properties that can be used to measure COVID-19 stigma during the COVID-19 outbreak or afterward among nurses. 

ASGR1 is a candidate receptor for SARS-CoV-2 that promotes infection of liver cells (preprint)

Currently, the COVID-19 pandemic, caused by SARS-CoV-2 infection, represents a serious public health problem worldwide. Although it has been shown that ACE2 serves as the main receptor for SARS-CoV-2 entry into host cells, studies have shown that ACE2 is expressed at extremely low levels in various tissues, especially in some organs where virus particles have been found, such as the heart and liver. Therefore, these organs potentially express additional SARS-CoV-2 receptors that have not yet been discovered. Here, by a genome-wide CRISPR-Cas9 activation library screening, we found that ASGR1 promoted SARS-CoV-2 infection of 293T cells. In Huh-7 and HepG2 cell lines, simultaneous knock out of ACE2 and ASGR1 prevented SARS-CoV-2 pseudovirus infection. In the immortalized THLE-2 hepatocyte cell line and primary liver parenchymal cells, both of which hardly express ACE2, SARS-CoV-2 could successfully establish an infection. After treatment with ASGR1 antibody, the infection rate significantly reduced. This suggests that SARS-CoV-2 infects liver cells mainly through an ASGR1-dependent mechanism. Finally, we also found that the soluble ASGR1 could not only prevent the SARS-CoV-2 pseudovirus, which binds to the ASGR1 receptors, from infecting host liver cells, but also had a protective effect on those expressing ACE2, indicating that administration of soluble ASGR1 protein may represent a new treatment approach. CONCLUSIONS: Colletively, these findings indicate that ASGR1 is a candidate receptor for SARS-CoV-2 that promotes infection of liver cells.

Angiotensin-converting enzyme 2 SNPs as the common genetic loci and optimal early identification genetic markers for COVID-19 (preprint)

Background: Angiotensin-converting enzyme 2 (ACE2) is implicated as a host cell receptor that causes infection in the pathogenesis of Coronavirus disease 2019 (COVID-19), and its genetic polymorphisms in the ACE2 gene may promote cardiovascular disease and systemic inflammatory injury in COVID-19. Hence, genetic background may potentially explain the broad inter-individual variation of disease susceptibility and/or severity. Methods The genetic susceptibility to COVID-19 by examining single-nucleotide polymorphisms (SNPs) of ACE2 was analyzed in 196 patients with COVID-19 and 210 normal controls using TaqMan genotyping assay. Results We demonstrated that ACE2 SNP rs4646142, rs6632677, and rs2074192 were associated with COVID-19 (all P < 0.05), and the differences of ACE2 SNPs rs4646142 and rs6632677 were correlated with COVID-19 related systemic inflammatory injury and cardiovascular risk. Specially, rs4646142 was associated with high-sensitive C-reactive protein (hs-CRP), prealbumin (PAB), apolipoprotein A (APOA), high-density lipoprotein (HDL), and acid glycoprotein (AGP). Rs6632677 was also associated with elevated CRP and haptoglobin (HPT). Conclusions Our results suggest that early identification of these individuals can provide a possible strategy for preventing the spread of the COVID-19, and ACE2 SNPs rs4646142 and rs6632677 may be a common genetic loci and optimal early identification genetic marker for COVID-19 with cardiovascular risks.

Novel neutralization mechanism of a human antibody with pan-coronavirus reactivity (preprint)

The recurrent outbreak of coronaviruses and variants underscores the need for broadly reactive antivirals and vaccines. Here, a novel broad-spectrum human antibody named 76E1 was isolated from a COVID-19 convalescent patient and showed broad neutralization activity against multiple α- and β-coronaviruses, including the SARS-CoV-2 variants and also exhibited the binding breath to peptides containing the epitope from γ- and δ- coronaviruses. 76E1 cross-protects mice from SARS-CoV-2 and HCoV-OC43 infection in both prophylactic and treatment models. The epitope including the fusion peptide and S2’ cleavage site recognized by 76E1 was significantly conserved among α-, β-, γ- and δ- coronaviruses. We uncovered a novel mechanism of antibody neutralization that the epitope of 76E1 was proportionally less exposed in the prefusion trimeric structure of spike protein but could be unmasked by binding to the receptor ACE2. Once the epitope exposed, 76E1 inhibited S2’ cleavage, thus blocked the membrane fusion process. Our data demonstrate a key epitope targeted by broadly-neutralizing antibodies and will guide next-generation epitope-based pan-coronavirus vaccine design.

The Impact of Policy and COVID-19 Prevention Strategies in China: A Qualitative Study (preprint)

The authors have requested that this preprint be removed from Research Square.

Comprehensive Mapping of Binding Hot Spots of SARS-CoV-2 RBD-specific Neutralizing Antibodies for Tracking Immune Escape Variants (preprint)

The receptor-binding domain (RBD) variants of SARS-CoV-2 could impair antibody-mediated neutralization of the virus by host immunity; thus, prospective surveillance for such antibody escape mutants is urgently needed. Here, we comprehensively profiled four antigenic sites of the RBD and mapped the binding hot spots for a panel of RBD-specific monoclonal antibodies isolated from COVID-19 convalescents, especially dominant VH3-53/3–66 antibodies, which are valuable indicators of antigenic changes in the RBD. We further demonstrated that several natural mutations, namely, K417N, F486L, N450K, L452R, E484K, F490S and R346S, significantly decreased the neutralizing activity of multiple human monoclonal antibodies and of human convalescent plasma obtained in the early stage of the COVID-19 pandemic. Of note, among the natural escape mutations, L452R enhanced ACE2 binding affinity, indicating that it potentially increased virulence. Overall, the in-depth maps may have far-reaching value for surveillance of SARS-CoV-2 immune escape variants and guidance of vaccine design.

Human Identical Sequences of SARS-CoV-2 Promote Clinical Progression of COVID-19 by Upregulating Hyaluronan via NamiRNA-Enhancer Network (preprint)

The COVID-19 pandemic is a widespread and deadly public health crisis. The pathogen SARS-CoV-2 replicates in the lower respiratory tract and causes fatal pneumonia. Although tremendous efforts have been put into investigating the pathogeny of SARS-CoV-2, the underlying mechanism of how SARS-CoV-2 interacts with its host is largely unexplored. Here, by comparing the genomic sequences of SARS-CoV-2 and human, we identified five fully conserved elements in SARS-CoV-2 genome, which were termed as "human identical sequences (HIS)". HIS are also recognized in both SARS-CoV and MERS-CoV genome. Meanwhile, HIS-SARS-CoV-2 are highly conserved in the primate. Mechanically, HIS-SARS-CoV-2 RNA directly binds to the targeted loci in human genome and further interacts with host enhancers to activate the expression of adjacent and distant genes, including cytokines gene and angiotensin converting enzyme II (ACE2), a well-known cell entry receptor of SARS-CoV-2, and hyaluronan synthase 2 (HAS2), which further increases hyaluronan formation. Noteworthily, hyaluronan level in plasma of COVID-19 patients is tightly correlated with severity and high risk for acute respiratory distress syndrome (ARDS) and may act as a predictor for the progression of COVID-19. HIS antagomirs, which downregulate hyaluronan level effectively, and 4-Methylumbelliferone (MU), an inhibitor of hyaluronan synthesis, are potential drugs to relieve the ARDS related ground-glass pattern in lung for COVID-19 treatment. Our results revealed that unprecedented HIS elements of SARS-CoV-2 contribute to the cytokine storm and ARDS in COVID-19 patients. Thus, blocking HIS-involved activating processes or hyaluronan synthesis directly by 4-MU may be effective strategies to alleviate COVID-19 progression.

The Volatile and Heterogenous Gut Microbiota Shifts of COVID-19 Patients Over The Course of A Probiotics-Assisted Therapy (preprint)

Background Coronavirus disease 2019 (COVID-19) has rapidly become a global pandemic, and little is known regarding the gut microbiota dynamics of the disease that often features a drastic and swift progression. Here we employed analyses of 16S rRNA gene sequencing and metatranscriptome to investigate the gut microbiome characteristics of a group of COVID-19 patients over the course of a probiotics-assisted therapy. Results The COVID-19 patients exhibited apparent microbiota alterations characterized by prominent compositional and functional shifts, which included taxonomic changes (e.g., increased relative abundance of Enterococcus and Rhodococcus, and decreased relative abundance of Faecalibacterium and Clostridium XlVa) and transcriptional changes (e.g., increased transcriptional activities of Escherichia coli and Klebsiella pneumoniae, virulence factors, and antibiotic resistance genes, and decreased activities of Faecalibacterium prausnitzii). Importantly, there were great interpersonal heterogeneity and intertimepoint fluctuations, as the most abundant or transcriptionally active taxa often greatly differed among individual patients and timepoints. Coincided with the resolution of respiratory symptoms, after the therapy some patients showed signs of recovery in the gut microbiome abnormalities. Associations were identified between gut and airway taxa and serum factors. Conclusion Our findings suggested that there is a lack of gut microbiota stability in COVID-19 patients and that measures are needed to ameliorate the gut microbiome perturbations in the patients to improve the prognosis. In addition, inclusion of probiotics is safe for treating COVID-19 patients and may improve their prognosis. Trial registration ISRCTN, ChiCTR2000029999. Registered 19 February 2020, http://www.chictr.org.cn/showprojen.aspx?proj=49717

Dynamic Clinical Features During the Para-Exacerbation Period of Critical COVID-19 Patients (preprint)

Background COVID-19 has been currently spread all over the world with high mortality reported in severe COVID-19 patients. Many severe COVID-19 patients exacerbated from mild illness several days after hospital admissions. Pathophysiological evolution within this para-exacerbation period remain unclear.Methods Twenty-two confirmed COVID-19 patients who underwent at least one exacerbation were included. Epidemiological, clinical, laboratory, and radiological data were extracted from electronic medical records and compared between the records of hospital admission day and the exacerbation day. Dynamic profiles of critical parameters were explored during the para-exacerbation period.Results Most of the patients were elder (67, IQR63-79), male (81.8%), coexisted with comorbidities (72.7%), multi-segments radiologically involved and exacerbated from mild to severe illness with anoxia at a median interval of 4 days (IQR, 2-7) from hospital admissions. On exacerbations, various clinical parameters were worsened, including respiratory rate, PaO2/FiO2 rate (PFR), alveolar-arterial PO2 difference (A-aDO2), hematological cellularities, biochemical parameters and radiological abnormalities. Dynamic profiles showed that neutrophil/lymphocyte ratio (NLR), and serum level of lactic acid, lactate dehydrogenase and coagulation parameters started to increase even at four days before the exacerbation. Conclusions Anoxia due to impaired gas exchange progress pathophysiologically characterized the exacerbation of COVID-19 patients. Continuously monitoring crucial clinical parameters, such as NLR, serum albumin, LDH, lactic acid, and CT involvement scale will be helpful to improve the recognition of the disease progression in patients with COVID-19 at early stage.Trial registration This retrospective study has been registered in Chinese Clinical Trial Registry (ChiCTR2000030580, www.chictr.org.cn)

Pharmacokinetics and Pharmacodynamics of Vancomycin in Severe COVID-19 Patients: a Preliminary Study in a Chinese Tertiary Hospital (preprint)

Vancomycin plays an important role in the treatment of concurrent infections in severe coronavirus disease 2019 (COVID-19) patients. However, few is known about its pharmacokinetics (PK) in these patients. Here we performed therapeutic drug monitoring (TDM) of intravenous vancomycin with or without nasal administration in these patients. Drug dosage was adjusted depending on vancomycin concentration. A population PK model was developed using NONMEM software. Therapeutic effects, and vancomycin-related adverse events were monitored. A total of 63 samples from 8 patients were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry. The mean trough and peak concentration were 13.79±6.61 (4.63-34.2) mg/L (n=36) and 30.97±9.71 (17-49.9) mg/L (n=27), respectively. 25.4% of serum vancomycin concentration was beyond optimal range. Dose adjustments were made for 3 patients. The PK of vancomycin was consistent with two-compartment model, with the clearance and distribution volume in the central compartment of 4.3 L/h and 2.0 L, respectively. The AUC0-24/MIC of vancomycin was 848±566 h. Target infection was clinically cured in all patients, and no vancomycin-associated nephrotoxicity was detected during the TDM process. In conclusion, the PK studies of vancomycin in COVID-19 patients are needed to optimize drug dosage. Based on our PK model, the clearance of vancomycin was 4.3 L/h. 

Dynamic Clinical Features During the Para-Exacerbation Period of Critical COVID-19 Patients (preprint)

Background COVID-19 has been currently spread all over the world with high mortality reported in severe COVID-19 patients. Many severe COVID-19 patients exacerbated from mild illness several days after hospital admissions. Pathophysiological evolution within this para-exacerbation period remain unclear.Methods Twenty-two confirmed COVID-19 patients who underwent at least one exacerbation were included. Epidemiological, clinical, laboratory, and radiological data were extracted from electronic medical records and compared between the records of hospital admission day and the exacerbation day. Dynamic profiles of critical parameters were explored during the para-exacerbation period.Results Most of the patients were elder (67, IQR63-79), male (81.8%), coexisted with comorbidities (72.7%), multi-segments radiologically involved and exacerbated from mild to severe illness with anoxia at a median interval of 4 days (IQR, 2-7) from hospital admissions. On exacerbations, various clinical parameters were worsened, including respiratory rate, PaO2/FiO2 rate (PFR), alveolar-arterial PO2 difference (A-aDO2), hematological cellularities, biochemical parameters and radiological abnormalities. Dynamic profiles showed that neutrophil/lymphocyte ratio (NLR), and serum level of lactic acid, lactate dehydrogenase and coagulation parameters started to increase even at four days before the exacerbation.Conclusions Anoxia due to impaired gas exchange progress pathophysiologically characterized the exacerbation of COVID-19 patients. Continuously monitoring crucial clinical parameters, such as NLR, serum albumin, LDH, lactic acid, and CT involvement scale will be helpful to improve the recognition of the disease progression in patients with COVID-19 at early stage.Trial registration: This retrospective study has been registered in Chinese Clinical Trial Registry (ChiCTR2000030580, www.chictr.org.cn)

Significance of neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio for predicting clinical outcomes in COVID-19 (preprint)

Background The epidemic of 2019 novel coronavirus (COVID-19) struck China in late December,2019, resulting in about 200000 deaths all over the world. Numerous observational studies have suggested that the neutrophil-to-lymphocyte ratio (NLR) and lymphocyte proportion and the platelet-to-lymphocyte ratio (PLR) are inflammatory markers. Our study aimed to detect the role of NLR, PLR in predicting the prognosis of COVID-19.Results Four hundred and fifteen consecutive patients were enrolled in Shanghai Public Health Clinical Center affiliated to Fudan University, between 20 January and 11 April 2020 with confirmed COVID-19,among which 386 (93%) patients were not severe, and 27 (7%) were severe. The proportion of males in severe cases is higher than in non-severe cases (75.86% vs. 50.52%, P = 0.008). The age between the two groups is different (p = 0.022). Compared with non-severe patients, severe patients exhibited more comorbidities, including hypertension (48.28% vs. 19.43%, p < 0.001), diabetes (20.69% vs. 6.99%, p = 0.009), chronic obstructive pulmonary disease (51.72% vs. 6.22%, p < 0.001), and fatty liver (37.93% vs. 15.8%, p = 0.002), respectively. NLR and PLR showed significant difference (p < 0.001). Diabetes (OR 0.28; 95% CI 15.824-187.186), fatty liver (OR 21.469; 95% CI 2.306-199.872), coronary heart disease (OR 18.157; 95% CI 2.085-158.083), NLR (OR 1.729; 95% CI 1.050–2.847) were significantly associated with severe cases with COVID-19. The NLR of patients in severe group had a 1.729-fold higher than that of no-severe group (OR 1.729; 95% CI 1.050–2.847, P = 0.031).Conclusions NLR is an independent risk factor of severe COVID-19 patients. PLR, NLR were significantly different between severe and non-severe patients, so assessment of NLR, PLR may help identify high risk cases with COVID-19.

Olfactory and Gustatory Dysfunction as An Early Identifier of COVID-19 in Adults and Children: An International Multicenter Study (preprint)

Abstract Objective: Evaluate the prevalence and characteristics of olfactory or gustatory dysfunction in COVID-19 patients Study Design: Multicenter Case Series Setting: 5 tertiary care hospitals (3 in China, 1 in France, 1 in Germany) Subjects and Methods: 394 PCR confirmed COVID-19 positive patients were screened, and those with olfactory or gustatory dysfunction were included. Data including demographics, COVID-19 severity, patient outcome, and the incidence and degree of olfactory and/or gustatory dysfunction were collected and analyzed. The Questionnaire of Olfactory Disorders (QOD) and Visual Analogue Scale (VAS) were used to quantify olfactory and gustatory dysfunction respectively. All subjects at one hospital (Shanghai) without subjective olfactory complaints underwent objective testing. Results: Of 394 screened subjects, 161 (41%) reported olfactory and/or gustatory dysfunction and were included. Incidence of olfactory and/or gustatory disorders in Chinese (n=239), German (n=39) and French (n=116) cohorts were 32%, 69%, and 49% 138 respectively. The median age of included subjects was 39 years old, 92/161 (57%) were male, and 10/161 (6%) were children. Of included subjects, 10% had only olfactory or gustatory symptoms, and 19% had olfactory and/or gustatory complaints prior to any other COVID-19 symptom. Of subjects with objective olfactory testing, 10/90 demonstrated abnormal chemosensory function despite reporting normal subjective olfaction. 43% (44/102) of subjects with follow-up showed symptomatic improvement in olfaction or gustation. Conclusions: Olfactory and/or gustatory disorders may represent early or isolated symptoms of SARS-CoV-2 infection. They may serve as a useful additional screening criterion, particularly for the identification of patients in the early stages of infection.

Significance of neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio for predicting clinical outcomes in COVID-19 (preprint)

Background: The epidemic of 2019 novel coronavirus (COVID-19) struck China in late December, 2019, resulting in about 200000 deaths all over the world. Numerous observational studies have suggested that the neutrophil-to-lymphocyte ratio (NLR) and lymphocyte proportion and the platelet-to-lymphocyte ratio (PLR) are inflammatory markers. Our study aimed to detect the role of NLR, PLR in predicting the prognosis of COVID-19. Methods: Four hundred and fifteen consecutive patients were enrolled in Shanghai Public Health Clinical Center affiliated to Fudan University, between 20 January and 11 April 2020 with confirmed COVID-19. Epidemiology, symptoms, signs, and laboratory examinations during the hospital stay were collected and compared between non-severe and severe patients. Statistical analysis was performed by SPSS 25.0 software. Results: Four hundred and fifteen laboratory-confirmed COVID-19 patients were included in our study, among which 386 (93%) patients were not severe, and 27 (7%) were severe. The proportion of males in severe cases is higher than in non-severe cases (75.86% vs. 50.52%, P=0.008). The age between the two groups is different (p=0.022). Compared with non-severe patients, severe patients exhibited more comorbidities, including hypertension (48.28% vs. 19.43%, p<0.001), diabetes (20.69% vs. 6.99%, p=0.009), chronic obstructive pulmonary disease (51.72% vs. 6.22%, p<0.001), and fatty liver (37.93% vs. 15.8%, p=0.002), respectively. NLR and PLR showed significant difference (p<0.001). Diabetes (OR 0.28; 95% CI 15.824-187.186), fatty liver (OR 21.469; 95% CI 2.306-199.872), coronary heart disease (OR 18.157; 95% CI 2.085-158.083), NLR (OR 1.729; 95% CI 1.050-2.847) were significantly associated with severe cases with COVID-19. The NLR of patients in severe group had a 1.729-fold higher than that of no-severe group (OR 1.729; 95% CI 1.050-2.847, P=0.031). Conclusions: NLR is an independent risk factor of severe COVID-19 patients. PLR, NLR were significantly different between severe and non-severe patients, so assessment of NLR, PLR may help identify high risk cases with COVID-19. Key words: Neutrophil-to-lymphocyte ratio, Platelet-to-lymphocyte ratio, COVID-19, Severity

A study on mental health status among the staff in a designated hospital for COVID- 19 (preprint)

Background: We investigate the mental health status of all the staff members who worked for the designated hospital during the initial stage of COVID-19, so as to understand the severity of mental health problems, and analyze the risk factors.Methods: Through the patients health questionnaire-9(PHQ-9) and panic disorder severity scales(PDSS), we surveyed the status of depression and panic disorder of the staff who participated in the prevention and treatment of COVID-19 in designated hospital in the early stage of epidemic. The data is described by the number of cases (percentage), median and interquartile range. The chi square test was used for categorical variables and the rank sum test was used for continuous variables. The risk factors of severe depression or panic disorder were analyzed by binary logistic regression test.Results: Totally 702 questionnaires were sent out and 694(98.9%) was received and qualified, the median score of PHQ-9 among all the staff was 1 (IQR,0-4), 143(20.6%) of them had depression, 39 (5.6%) had serious depression; the median score of PDSS was 2 (IQR,0-5), 81 (11.7%) of them had panic disorder and 47(6.7%) of them had severe panic disorder; Among the people in different work lines, the first-line staff scored the highest: PHQ-9 score was 4 (0-8); PDSS score was 4 (1-9), which were significantly higher than the second-line and third-line staff (P<0.001). Multivariate logistic regression analysis showed that the adjusted risk of severe depression in first-line staff was 6.63 fold(P < 0.001); the risk of severe panic disorder was 2.62 fold (P=0.003) higher than that of non-first line group.Conclusions: Many staff in the designated hospital for COVID-19 have mental health problems. Among them, first-line workers are a high-risk group with severe depression and panic disorder, and further psychological intervention is needed for them.

Neutralizing Antibody Responses to SARS-CoV-2 in a COVID-19 Recovered Patient Cohort and Their Implications (preprint)

Background: The COVID-19 pandemic caused by SARS-CoV-2 coronavirus threatens global public health. Currently, neutralizing antibodies (NAbs) versus this virus are expected to correlate with recovery and protection of this disease. However, the characteristics of these antibodies have not been well studied in association with the clinical manifestations in patients. Methods: Plasma collected from 175 COVID-19 recovered patients with mild symptoms were screened using a safe and sensitive pseudotyped-lentiviral-vector-based neutralization assay. Spike-binding antibody in plasma were determined by ELISA using RBD, S1, and S2 proteins of SARS-CoV-2. The levels and the time course of SARS-CoV-2-specific NAbs and the spike-binding antibodies were monitored at the same time. Findings: SARS-CoV-2 NAbs were unable to cross-reactive with SARS-CoV virus. SARS-CoV-2-specific NAbs were detected in patients from day 10-15 after the onset of the disease and remained thereafter. The titers of NAb among these patients correlated with the spike-binding antibodies targeting S1, RBD, and S2 regions. The titers of NAbs were variable in different patients. Elderly and middle-age patients had significantly higher plasma NAb titers (P<0·0001) and spike-binding antibodies (P=0·0003) than young patients. Notably, among these patients, there were ten patients whose NAb titers were under the detectable level of our assay (ID50: < 40); while in contrast, two patients, showed very high titers of NAb, with ID50 :15989 and 21567 respectively. The NAb titers were positive correlated with plasma CRP levels but negative correlated with the lymphocyte counts of patients at the time of admission, indicating an association between humoral response and cellular immune response. Interpretation: The variations of SARS-CoV-2 specific NAbs in recovered COVID-19 patients may raise the concern about the role of NAbs on disease progression. The correlation of NAb titers with age, lymphocyte counts, and blood CRP levels suggested that the interplay between virus and host immune response in coronavirus infections should be further explored for the development of effective vaccine against SARS-CoV-2 virus. Furthermore, titration of NAb is helpful prior to the use of convalescent plasma for prevention or treatment. Funding Statement: This work was supported by the National Major Science and Technology Projects of China (2017ZX10202102 and 2018ZX10301403), National Natural Science Foundation of China (31771008), Hundred Talent Program of Shanghai Municipal Health Commission (2018BR08), and Chinese Academy of Medical Sciences (2019PT350002). Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: The study was conducted under a clinical protocol approved by the Investigational Review Board in the Shanghai Public Health Clinical Center (Study number: YJ-2020-S021-01). All participants signed an informed consent approved by the IRB.

Neutralizing antibody responses to SARS-CoV-2 in a COVID-19 recovered patient cohort and their implications (preprint)

Background The COVID-19 pandemic caused by SARS-CoV-2 coronavirus threatens global public health. Currently, neutralizing antibodies (NAbs) versus this virus are expected to correlate with recovery and protection of this disease. However, the characteristics of these antibodies have not been well studied in association with the clinical manifestations in patients. Methods Plasma collected from 175 COVID-19 recovered patients with mild symptoms were screened using a safe and sensitive pseudotyped-lentiviral-vector-based neutralization assay. Spike-binding antibody in plasma were determined by ELISA using RBD, S1, and S2 proteins of SARS-CoV-2. The levels and the time course of SARS-CoV-2-specific NAbs and the spike-binding antibodies were monitored at the same time. Findings SARS-CoV-2 NAbs were unable to cross-reactive with SARS-CoV virus. SARS-CoV-2-specific NAbs were detected in patients from day 10-15 after the onset of the disease and remained thereafter. The titers of NAb among these patients correlated with the spike-binding antibodies targeting S1, RBD, and S2 regions. The titers of NAbs were variable in different patients. Elderly and middle-age patients had significantly higher plasma NAb titers (P<0.0001) and spike-binding antibodies (P=0.0003) than young patients. Notably, among these patients, there were ten patients whose NAb titers were under the detectable level of our assay (ID50: < 40); while in contrast, two patients, showed very high titers of NAb, with ID50 :15989 and 21567 respectively. The NAb titers were positive correlated with plasma CRP levels but negative correlated with the lymphocyte counts of patients at the time of admission, indicating an association between humoral response and cellular immune response. Interpretation The variations of SARS-CoV-2 specific NAbs in recovered COVID-19 patients may raise the concern about the role of NAbs on disease progression. The correlation of NAb titers with age, lymphocyte counts, and blood CRP levels suggested that the interplay between virus and host immune response in coronavirus infections should be further explored for the development of effective vaccine against SARS-CoV-2 virus. Furthermore, titration of NAb is helpful prior to the use of convalescent plasma for prevention or treatment. Funding Ministry of Science and Technology of China, National Natural Science Foundation of China, Shanghai Municipal Health Commission, and Chinese Academy of Medical Sciences