Characteristics of viral shedding in people infected with SARS-CoV-2 during difference stages

Viral shedding of SARS-CoV-2 is a continuous dynamic process, which can be divided into latent stage, initial stage, peak stage and decreasing stage according to the characteristics of viral shedding. After being infected with SARS-CoV-2, the infected person generally stays in the latent period for 1-3 days, which is characterized by continuous negative nucleic acid test results and no infectiousness, and the risk of infection for close contacts is very low. At the initial stage of viral shedding is characterized by a rapid decline in the Ct value of nucleic acid tests in a short time, and clinical symptoms gradually appear. The infectiousness of the infected person gradually increases during this period, and the risk of infection for close contacts also gradually increases, but it is still in the early stage of infection, the possibility of viral shedding is low, and the risk of infection of secondary close contacts is low. The peak of viral shedding is characterized by low Ct value in nucleic acid test and obvious clinical symptoms;during this period, the infected person is the most infectious, and the risk of infection of the contact is the highest, so the scope of close contacts should be expanded appropriately. The decreasing period is characterized by the gradual increase of Ct value of nucleic acid test and the gradual disappearance of clinical symptoms;during this period, the infectiousness of the infected person gradually decreases to disappear. In an outbreak, an infected person in the decreasing phase is more likely to be an early infected person in the transmission chain. If infected individuals in the decreasing phase are found in an area without a SARS-CoV-2 epidemic, it suggests that the local outbreak epidemic has been spreading for some time and may be larger in scale. According to the characteristics of viral shedding, risk personnel can be determined more scientifically and accurately, so as to minimize the risk and reduce the waste of epidemic prevention resources.

Disparities in COVID-19 clinical studies from high-income and low-and middle-income countries.

OBJECTIVES: To examine the disparities between COVID-19 studies conducted in high-income countries (HICs) and low-and middle-income countries (LMICs). METHODS: We used the International Clinical Trials Registry Platform to identify COVID-19-related studies registered from December 31, 2019 to December 31, 2021. The World Bank definition was used to classify countries as high-, upper-middle-, lower-middle-, and low-income. The last three were considered to be LMICs. We examined the disparities in response speed, classification of medicines and vaccines, and registration and results reporting compliance between COVID-19 studies conducted in HICs and LMICs. RESULTS: We included 12,396 COVID-19 studies, with 6631 (53.5%) from HICs. HIC-registered studies reached a peak of 1039 in April 2020, whereas LMICs had only 440 studies. Of the 6969 interventional trials, those from HICs showed higher registration compliance (2199, 62.3% vs 1979, 57.6%, P <0.001) and results reporting compliance (hazard ratio 0.39, 95% confidence interval 0.28-0.55, P < 0.001) than LMICs. HICs also conducted significantly more small-molecule drug (956, 57.5% vs 868, 41.2%, P <0.001) and messenger RNA vaccine trials (135, 32.9% vs 19, 4.8%, P <0.001) than LMICs. CONCLUSION: HICs conducted COVID-19 trials with faster response speed and higher registration and publication compliance and produced more innovative pharmaceutical and vaccine products to combat COVID-19 than LMICs.

Clinical Characteristics and Abnormal Parameters Evolution in Patients With Novel Coronavirus Infection: A Case Series of 272 Cases in Guangzhou.

OBJECTIVE: The aim of this study was to present the clinical characteristics and dynamic changes in laboratory parameters of the coronavirus disease 2019 (COVID-19) in Guangzhou, and explore the probable early warning indicators of disease progression. METHOD: We enrolled all the patients diagnosed with COVID-19 in the Guangzhou No. 8 People's Hospital. The patients' demographic and epidemiologic data were collected, including chief complaints, lab results, and imaging examination findings. RESULTS: The characteristics of the patients in Guangzhou are different from those in Wuhan. The patients were younger in age, predominately female, and their condition was not commonly combined with other diseases. A total of 75% of patients suffered fever on admission, followed by cough occurring in 62% patients. Comparing the mild/normal and severe/critical patients, being male, of older age, combined with hypertension, abnormal blood routine test results, raised creatine kinase, glutamic oxaloacetic transaminase, lactate dehydrogenase, C-reactive protein, procalcitonin, D-dimer, fibrinogen, activated partial thromboplastin time, and positive proteinuria were early warning indicators of severe disease. CONCLUSION: The patients outside epidemic areas showed different characteristics from those in Wuhan. The abnormal laboratory parameters were markedly changed 4 weeks after admission, and also were different between the mild and severe patients. More evidence is needed to confirm highly specific and sensitive potential early warning indicators of severe disease.

Risk perception and gratitude mediate the negative relationship between COVID-19 management satisfaction and public anxiety.

In this study, we explored whether satisfaction with government management, perception of risk, and gratitude influenced public anxiety during the COVID-19 pandemic in China. Using a cross-sectional, anonymous and confidential online survey, a nationwide sample of Chinese adults (N = 876) was targeted between March 25-March 30, 2020, a period in which newly confirmed cases significantly declined in China. The anxiety level was decreased as compared to that assessed during the peak period. Multiple parallel mediation modeling demonstrated that risk perception and gratitude partially mediated the relationship between satisfaction with government management and public anxiety. Increasing satisfaction and gratitude, as well as reducing risk perception contribute to the public's mental health. The results may shed light on the positive factors for psychological well-being during the COVID-19 pandemic and may aid potential strategies for the policy maker, the public, and the clinic to regulate negative emotions or future emerging infectious diseases.

Alpha-Soluble NSF Attachment Protein Prevents the Cleavage of the SARS-CoV-2 Spike Protein by Functioning as an Interferon-Upregulated Furin Inhibitor.

Loss of the furin cleavage motif in the SARS-CoV-2 spike protein reduces the virulence and transmission of SARS-CoV-2, suggesting that furin is an attractive antiviral drug target. However, lack of understanding of the regulation of furin activity has largely limited the development of furin-based therapeutic strategies. Here, we find that alpha-soluble NSF attachment protein (α-SNAP), an indispensable component of vesicle trafficking machinery, inhibits the cleavage of SARS-CoV-2 spike protein and other furin-dependent virus glycoproteins. SARS-CoV-2 infection increases the expression of α-SNAP, and overexpression of α-SNAP reduces SARS-CoV-2 infection in cells. We further reveal that α-SNAP is an interferon-upregulated furin inhibitor that inhibits furin function by interacting with its P domain. Our study demonstrates that α-SNAP, in addition to its role in vesicle trafficking, plays an important role in the host defense against furin-dependent virus infection and therefore could be a target for the development of therapeutic options for COVID-19. IMPORTANCE Some key mutations of SARS-CoV-2 spike protein, such as D614G and P681R mutations, increase the transmission or pathogenicity by enhancing the cleavage efficacy of spike protein by furin. Loss of the furin cleavage motif of SARS-CoV-2 spike protein reduces the virulence and transmission, suggesting that furin is an attractive antiviral drug target. However, lack of understanding of the regulation of furin activity has largely limited the development of furin-based therapeutic strategies. Here, we found that in addition to its canonical role in vesicle trafficking, alpha-soluble NSF attachment protein (α-SNAP) plays an important role in the host defense against furin-dependent virus infection. we identified that α-SNAP is a novel interferon-upregulated furin inhibitor and inhibits the cleavage of SARS-CoV-2 spike protein and other furin-dependent virus glycoproteins by interacting with P domain of furin. Our study demonstrates that α-SNAP could be a target for the development of therapeutic options for COVID-19.

Transferrin Receptor Protein 1 Cooperates with mGluR2 To Mediate the Internalization of Rabies Virus and SARS-CoV-2.

Identification of bona fide functional receptors and elucidation of the mechanism of receptor-mediated virus entry are important to reveal targets for developing therapeutics against rabies virus (RABV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Our previous studies suggest that metabotropic glutamate receptor subtype 2 (mGluR2) functions as an entry receptor for RABV in vitro, and is an important internalization factor for SARS-CoV-2 in vitro and in vivo. Here, we demonstrate that mGluR2 facilitates RABV internalization in vitro and infection in vivo. We found that transferrin receptor 1 (TfR1) interacts with mGluR2 and internalizes with mGluR2 and RABV in the same clathrin-coated pit. Knockdown of TfR1 blocks agonist-triggered internalization of mGluR2. Importantly, TfR1 also interacts with the SARS-CoV-2 spike protein and is important for SARS-CoV-2 internalization. Our findings identify a novel axis (mGluR2-TfR1 axis) used by RABV and SARS-CoV-2 for entry, and reveal TfR1 as a potential target for therapeutics against RABV and SARS-CoV-2. IMPORTANCE We previously found that metabotropic glutamate receptor subtype 2 (mGluR2) is an entry receptor for RABV in vitro, and an important internalization factor for SARS-CoV-2 in vitro and in vivo. However, whether mGluR2 is required for RABV infection in vivo was unknown. In addition, how mGluR2 mediates the internalization of RABV and SARS-CoV-2 needed to be resolved. Here, we found that mGluR2 gene knockout mice survived a lethal challenge with RABV. To our knowledge, mGluR2 is the first host factor to be definitively shown to play an important role in RABV street virus infection in vivo. We further found that transferrin receptor protein 1 (TfR1) directly interacts and cooperates with mGluR2 to regulate the endocytosis of RABV and SARS-CoV-2. Our study identifies a novel axis (mGluR2-TfR1 axis) used by RABV and SARS-CoV-2 for entry and opens a new door for the development of therapeutics against RABV and SARS-CoV-2.

Diltiazem inhibits SARS-CoV-2 cell attachment and internalization and decreases the viral infection in mouse lung

Since the outbreak of the new crown pneumonia, the new coronavirus (SARSCoV-2) has been mutating continuously, and it has now become prevalent in more than 200 countries. The cumulative number of confirmed cases in the world has exceeded 460 million, and the number of deaths has exceeded 6 million. The rapid mutation of SARS-CoV-2 highlights the importance of preventive and therapeutic drugs, however, effective therapeutic drugs for new coronary pneumonia are still very scarce. It is still the common goal of scientists from all over the world to develop a safe and effective drug for the treatment of new coronary pneumonia that can inhibit the infection of multiple SARS-CoV-2 mutant strains.

Alpha-soluble NSF attachment protein prevents the cleavage of the SARS-CoV-2 spike protein by functioning as an interferon-upregulated furin inhibitor

The new coronavirus (SARS-CoV-2) is raging around the world, infecting more than 460 million people and killing more than 6 million people, posing a serious threat to human health. Analyzing the pathogenic mechanism of the virus and discovering new drug targets are the keys to the development of antiviral drugs. Similar to the envelope proteins of many important viruses such as Ebola virus and Marburg virus, the spike (S) protein of SARS-CoV-2 relies on the cleavage and processing of cellular furin to mature during infection, and then make the virus infective, so furin is an important potential target for antiviral therapy. However, the regulation mechanism of furin enzyme activity in cells under physiological and infection conditions is not yet very clear.

From Biotechnology to Bioeconomy: A Review of Development Dynamics and Pathways

Based on the logistic growth model, the relationship between technology innovation and the evolution of economic forms was analyzed, and the main characteristics and basic laws of the five economic forms of hunter–gatherer, agriculture, industry, information, and bioeconomy were summarized. Based on a comprehensive and intensive scan of the latest bioeconomy development strategies of various countries, we summarized their two main driving forces from the technological supply side and economic and social demand side, as well as their four distinctive features, namely the comprehensiveness of science and technology innovation, the aggregation of industrial development, the globalization of development goals, and strong policy dependence. Finally, we proposed countermeasures to design the implementation path of the bioeconomy and improve the quality of the bioeconomy factor supply in terms of the development and application of biotechnology, the upgradation of bioindustry clusters, the positive policy environment, and the theorization of the bioeconomy.

Diltiazem inhibits SARS-CoV-2 cell attachment and internalization and decreases the viral infection in mouse lung.

The continuous emergence of severe acute respiratory coronavirus 2 (SARS-CoV-2) variants and the increasing number of breakthrough infection cases among vaccinated people support the urgent need for research and development of antiviral drugs. Viral entry is an intriguing target for antiviral drug development. We found that diltiazem, a blocker of the L-type calcium channel Cav1.2 pore-forming subunit (Cav1.2 α1c) and an FDA-approved drug, inhibits the binding and internalization of SARS-CoV-2, and decreases SARS-CoV-2 infection in cells and mouse lung. Cav1.2 α1c interacts with SARS-CoV-2 spike protein and ACE2, and affects the attachment and internalization of SARS-CoV-2. Our finding suggests that diltiazem has potential as a drug against SARS-CoV-2 infection and that Cav1.2 α1c is a promising target for antiviral drug development for COVID-19.

Associated Effects of Meaning in Life and Social Adjustment Among Chinese Undergraduate Students With Left-Behind Experiences in the Post-epidemic Period.

Background: The outbreak of COVID-19 has brought about radical changes in social life. The study focuses on a special group, Chinese undergraduate students with left-behind experiences. Specifically, the study addresses how such students feel and grasp the meaning in life and how they adapt to the current social environment after experiencing the impermanence of life. The correlation between the meaning in life and social adjustment in the post-epidemic period is evaluated. Methods: The Meaning in Life Scale and the Social Adjustment Scale were used to test 988 undergraduate students. Multi-factor analysis, correlation, regression, and dominance analysis were performed on the test results. Results: (1) During the epidemic, Chinese undergraduate students generally had low meaning in life scores, including below-average values for life goals, and middle-range scores for social adjustment. (2) Having or not having left-behind experiences had an important influence on the meaning in life and social adjustment of undergraduates: undergraduates with left-behind experiences performed better than those without left-behind experiences in terms of meaning in life, while their social adjustment was weaker than those without left-behind experiences. (3) The zest for life and freedom of life of undergraduates in both groups negatively predicted social adjustment, and zest for life preferentially influenced social adjustment. Zest for life also had a significant effect on life value in the group without left-behind experiences. Zest for life was a priority factor influencing social adjustment. Conclusion: The epidemic and left-behind experiences are important factors influencing the relationship between meaning in life and social adjustment among Chinese undergraduate students.

SARS-CoV-2 uses metabotropic glutamate receptor subtype 2 as an internalization factor to infect cells.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) uses angiotensin-converting enzyme 2 (ACE2) as a binding receptor to enter cells via clathrin-mediated endocytosis (CME). However, receptors involved in other steps of SARS-CoV-2 infection remain largely unknown. Here, we found that metabotropic glutamate receptor subtype 2 (mGluR2) is an internalization factor for SARS-CoV-2. Our results show that mGluR2 directly interacts with the SARS-CoV-2 spike protein and that knockdown of mGluR2 decreases internalization of SARS-CoV-2 but not cell binding. Further, mGluR2 is uncovered to cooperate with ACE2 to facilitate SARS-CoV-2 internalization through CME and mGluR2 knockout in mice abolished SARS-CoV-2 infection in the nasal turbinates and significantly reduced viral infection in the lungs. Notably, mGluR2 is also important for SARS-CoV spike protein- and Middle East respiratory syndrome coronavirus spike protein-mediated internalization. Thus, our study identifies a novel internalization factor used by SARS-CoV-2 and opens a new door for antiviral development against coronavirus infection.

Clinical Characteristics of Coronavirus Disease 2019 in China.

BACKGROUND: Since December 2019, when coronavirus disease 2019 (Covid-19) emerged in Wuhan city and rapidly spread throughout China, data have been needed on the clinical characteristics of the affected patients. METHODS: We extracted data regarding 1099 patients with laboratory-confirmed Covid-19 from 552 hospitals in 30 provinces, autonomous regions, and municipalities in mainland China through January 29, 2020. The primary composite end point was admission to an intensive care unit (ICU), the use of mechanical ventilation, or death. RESULTS: The median age of the patients was 47 years; 41.9% of the patients were female. The primary composite end point occurred in 67 patients (6.1%), including 5.0% who were admitted to the ICU, 2.3% who underwent invasive mechanical ventilation, and 1.4% who died. Only 1.9% of the patients had a history of direct contact with wildlife. Among nonresidents of Wuhan, 72.3% had contact with residents of Wuhan, including 31.3% who had visited the city. The most common symptoms were fever (43.8% on admission and 88.7% during hospitalization) and cough (67.8%). Diarrhea was uncommon (3.8%). The median incubation period was 4 days (interquartile range, 2 to 7). On admission, ground-glass opacity was the most common radiologic finding on chest computed tomography (CT) (56.4%). No radiographic or CT abnormality was found in 157 of 877 patients (17.9%) with nonsevere disease and in 5 of 173 patients (2.9%) with severe disease. Lymphocytopenia was present in 83.2% of the patients on admission. CONCLUSIONS: During the first 2 months of the current outbreak, Covid-19 spread rapidly throughout China and caused varying degrees of illness. Patients often presented without fever, and many did not have abnormal radiologic findings. (Funded by the National Health Commission of China and others.).

The Effect of Recombinant Human Interferon Alpha Nasal Drops to Prevent COVID-19 Pneumonia for Medical Staff in an Epidemic Area.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), known as Coronavirus disease-2019 (COVID-19), has caused the sixth world's public health emergency. Healthcare staff, as the frontline population fighting the pandemic, are exposed to a high risk of infection. Therefore, developing a protective intervention for medical staff is of significant importance. OBJECTIVE: The aim of the study was to explore the effectiveness and safety of recombinant human interferon alpha (rhIFN-α) nasal drops for the prevention of coronavirus disease 2019 (COVID-19) through administering it to medical staff. METHODS: This was a prospective open-label clinical trial with parallel intervention assignment conducted on 2944 medical staff including both doctors and nurses from Taihe Hospital, Shiyan City, Hubei Province, China from January 21, 2020 to July 30, 2020. The participants were bifurcated into two groups of low risk and high risk groups according to the level of direct exposure to COVID-19 patients. The individuals of the low-risk group received rhIFN-α nasal drops for one month in addition to first level protection, and the high-risk group received a combination of rhIFN-α nasal drops coupled with thymosin-α1 with either second or third-level protection protocol. Moreover, the new-outset of COVID-19 pneumonia diagnosed by chest computed tomography (CT), after thirty days, was the primary outcome. The adverse reactions were recorded in all participants. RESULTS: 2415 of 2944 individuals belonged to the low-risk group, while 529 to the high-risk group. There was no COVID-19 pneumonia in either of the group after thirty days. The pulmonary CT scans were negative for COVID-19 pneumonia in both the groups with no new clinical symptoms. No serious adverse event was observed during the course of the intervention. CONCLUSION: The rhIFN-α nasal drops along with augmented safeguards based on standard physical isolation could effectively protect medical staff against COVID-19 pneumonia.

Risk Factors of Fatal Outcome in Hospitalized Subjects With Coronavirus Disease 2019 From a Nationwide Analysis in China.

BACKGROUND: The novel coronavirus disease 2019 (COVID-19) has become a global health emergency. The cumulative number of new confirmed cases and deaths are still increasing out of China. Independent predicted factors associated with fatal outcomes remain uncertain. RESEARCH QUESTION: The goal of the current study was to investigate the potential risk factors associated with fatal outcomes from COVID-19 through a multivariate Cox regression analysis and a nomogram model. STUDY DESIGN AND METHODS: A retrospective cohort of 1,590 hospitalized patients with COVID-19 throughout China was established. The prognostic effects of variables, including clinical features and laboratory findings, were analyzed by using Kaplan-Meier methods and a Cox proportional hazards model. A prognostic nomogram was formulated to predict the survival of patients with COVID-19. RESULTS: In this nationwide cohort, nonsurvivors included a higher incidence of elderly people and subjects with coexisting chronic illness, dyspnea, and laboratory abnormalities on admission compared with survivors. Multivariate Cox regression analysis showed that age ≥ 75 years (hazard ratio [HR], 7.86; 95% CI, 2.44-25.35), age between 65 and 74 years (HR, 3.43; 95% CI, 1.24-9.5), coronary heart disease (HR, 4.28; 95% CI, 1.14-16.13), cerebrovascular disease (HR, 3.1; 95% CI, 1.07-8.94), dyspnea (HR, 3.96; 95% CI, 1.42-11), procalcitonin level > 0.5 ng/mL (HR, 8.72; 95% CI, 3.42-22.28), and aspartate aminotransferase level > 40 U/L (HR, 2.2; 95% CI, 1.1-6.73) were independent risk factors associated with fatal outcome. A nomogram was established based on the results of multivariate analysis. The internal bootstrap resampling approach suggested the nomogram has sufficient discriminatory power with a C-index of 0.91 (95% CI, 0.85-0.97). The calibration plots also showed good consistency between the prediction and the observation. INTERPRETATION: The proposed nomogram accurately predicted clinical outcomes of patients with COVID-19 based on individual characteristics. Earlier identification, more intensive surveillance, and appropriate therapy should be considered in patients at high risk.

Simultaneous detection and differentiation of SARS-CoV-2, influenza A virus and influenza B virus by one-step quadruplex real-time RT-PCR in patients with clinical manifestations.

OBJECTIVE: To develop a novel quadruplex real-time reverse transcription polymerase chain reaction (rRT-PCR) assay for the diagnosis of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, differential diagnosis and detection of co-infections. METHODS: A one-step quadruplex rRT-PCR assay was developed for simultaneous detection and differentiation of SARS-CoV-2 ORF1ab and N genes, influenza A virus (hIAV) and influenza B virus (hIBV). RESULTS: The quadruplex rRT-PCR assay had good sensitivity and specificity. Correlation coefficients and amplification efficiencies of all singleplex and quadruplex rRT-PCR reactions were within acceptable ranges. The 95% lower limits of detection for plasmid standards and positive nucleic acid extracts of the quadruplex rRT-PCR assay were 57.38-95.11 copies/µL and 114.65-154.25 copies/µL, respectively. Excellent results were attained for inter- and intra-assay reproducibility. Among these clinical samples, only four samples showed results inconsistent with the singleplex rRT-PCR assays. CONCLUSIONS: To the authors' knowledge, this is the first study to report a quadruplex rRT-PCR assay for the detection of two SARS-CoV-2 genes, hIAV and hIBV with perfect clinical performance.

Comparative Analysis of 95 Patients with Different Severity in the Early Outbreak of COVID-19 in Wuhan, China.

OBJECTIVE: To explore the clinical characteristics of patients with different severity in the early outbreak of COVID-19, hoping to provide reference for clinical diagnosis and treatment. METHODS: We retrospectively analyzed the clinical data of 95 COVID-19 patients in Wuhan Red Cross Hospital of China from January 17 to February 13, 2020. All patients were investigated with epidemiological questionnaires. Outcomes were followed up until April 1, 2020. RESULTS: There were 53 males and 42 females, aged 22-84 years (mean 57.3 years). Clinical classification included 54 cases of common type, 27 cases of severe type, and 14 cases of critical type. Six patients had been exposed to the local Huanan seafood market. There were 38 clusters of COVID-19, including 27 family clusters and 11 work unit clusters. Common symptoms included fever (86 (90.5%) of 95), cough (73 (76.8%)), and fatigue (50 (52.6%)). Laboratory findings showed that the most common abnormalities were lymphopenia (75 (78.9%)), elevated D-dimer (60 (63.2%)), and elevated C-reactive protein (56 (58.9%)) on admission. All patients had abnormal chest computed tomography, showing patchy shadows or ground-glass opacities. Severe and critical cases were older, more likely to have shortness of breath, more likely to have underlying comorbidities, and more likely to have abnormal laboratory findings than common cases. The prognosis of patients with different degrees of severity was significantly different. All common and severe patients (100%) were cured and discharged from the hospital, while 10 (71.4%) of 14 critical patients died. CONCLUSIONS: COVID-19 has fast transmission speed and high pathogenicity. We must assess the severity of the disease and take corresponding treatment measures as early as possible.