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1.
SSRN; 2022.
Preprint in English | SSRN | ID: ppcovidwho-331499

ABSTRACT

Background: Beyond its direct effects on mortality, the COVID-19 pandemic has disrupted the provision of health care services across numerous countries, giving rise to indirect but nevertheless significant impacts on public health. Methods: This study assesses how the COVID-19 pandemic has influenced health service utilization in terms of the difference between predicted and observed values with the number of COVID-19 confirmed cases, reporting the results of a time-series approach used to forecast annual and monthly health service utilization as compared with the actual results. This includes considering the number of confirmed cases, data on healthcare services and social-economic and demographic data relating to each province of China covered. The results of a multiple regression analysis are also reported to shed light on determine the relationship between the severity of pandemics and health service utilization. Findings: For the annual projections, we found a significantly negative correlation between the utilization of health services in hospitals and the number of confirmed cases, and the impact on inpatient services has been greater than that on outpatient services. With respect to the monthly analysis, as the pandemic moves from outbreak to dissemination, health care utilization is less affected. It is also found that the trough period for outpatient services has been shorter than that for inpatient services and the pandemic has had a greater impact on hospital services than on township health center services, especially during the first phase of the concentrated outbreak. At the same time, the proportion of educated persons within the population was a protective factor for the utilization of both inpatient and outpatient services. Interpretation: This study is conducted to estimate the impact of the COVID-19 pandemic and its severity on the chosen healthcare system. Given that during the COVID-19 pandemic the utilization of health services has declined significantly, there is a need to have greater regard to the potential for disruption among health services and healthcare systems in all Low-and Middle-Income Countries (LMIC).

2.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-313731

ABSTRACT

Background: Real-world evidence (RWE) of a vaccine supplements clinical trial data by providing information in populations differing from clinical trial populations, under different epidemiological situations, on alternative outcomes, or against different pathogen lineages. To date, RWE on inactivated COVID-19 vaccines against the highly transmissible SARS-CoV-2 B.1.617.2 (Delta) variant is limited, leaving an important gap in the evidence base of inactivated COVID-19 vaccines for use by immunization programs. Methods: Between May and June 2021, an outbreak of the B.1.617.2 variant was discovered and traced in Guangdong, China. Before this outbreak, Guangdong province had started mass vaccination using inactivated vaccines approved by China’s regulator for use in adults. Using surveillance and vaccination data from the outbreak, we assessed the real-world effectiveness of inactivated vaccines against pneumonia and severe illness caused by the B.1.617.2 variant. We enrolled 10813 subjects who were close contacts of laboratory-confirmed cases, categorizing them as an unvaccinated group, a partially vaccinated (1-dose) group, and a fully vaccinated (2-dose) group. We estimated relative risk (RR) and vaccine effectiveness (VE) of the vaccinated groups in relation to the unvaccinated group. Findings: Unadjusted and adjusted VE of full vaccination against pneumonia were 77·7% (95% CI 45·1–90·9) and 69·5% (95% CI 42·8–96·3), respectively. Full vaccination was 100% effective against severe illness. Unadjusted and adjusted VE of partial vaccination against pneumonia were 1·4% (95% CI -79·7–45·9) and 8·4% (95% CI -47·6–64·4). Interpretation Full vaccination with inactivated vaccines is effective against pneumonia, severe, and critical illness caused by the B.1.617.2 variant. Effort should be placed to ensure full vaccination of target populations. Funding: National Natural Science Foundation of China and Key-Area Research and Development Program of Guangdong.Declaration of Interest: None to declare. Ethical Approval: This study was approved by the institutional ethics committee of the Guangdong Provincial Center for Disease Control and Prevention (GDCDC). Data in the study were collected per administrative requirements of disease control and surveillance, and were anonymized for analysis. Participants were informed about the requirements of disease surveillance and provided oral consents.

3.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-313423

ABSTRACT

Coronavirus disease 2019 is pandemic across the world since the severe acute respiratory coronavirus-2 emerged in December 2019. The most efficient method to defend COVID 19 is vaccine. Here, we used HEK293 cell line to produce the recombinant protein and compared several vaccine candidates’ efficiency. The structures of the candidates were designed based on the S1 protein and RBD region. After three doses, the vaccines induced SARS-CoV-2 specific neutralizing antibodies in mice which presented high titers. The maximum neutralization activity could reach more than 90% without inflammation suggesting the great neutralizing ability against SARS-CoV-2.

4.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-313396

ABSTRACT

Infectious diseases are caused by pathogenic microorganisms, such as bacteria, viruses, parasites or fungi, which can be spread, directly or indirectly, from one person to another. Infectious diseases pose a serious threat to human health, especially COVID-19 that has became a serious worldwide health concern since the end of 2019. Contact tracing is the process of identifying, assessing, and managing people who have been exposed to a disease to prevent its onward transmission. Contact tracing can help us better understand the transmission link of the virus, whereby better interrupting its transmission. Given the worldwide pandemic of COVID-19, contact tracing has become one of the most critical measures to effectively curb the spread of the virus. This paper presents a comprehensive survey on contact tracing, with a detailed coverage of the recent advancements the models, digital technologies, protocols and issues involved in contact tracing. The current challenges as well as future directions of contact tracing technologies are also presented.

5.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-312713

ABSTRACT

Background: An ideal animal model to study SARS-coronavirus 2 (SARS-CoV-2) pathogenesis and evaluate therapies and vaccines should reproduce SARS-CoV-2 infection and recapitulate lung disease like those seen in humans. The angiotensin-converting enzyme 2 (ACE2) is a functional receptor for SARS-CoV-2, but mice are resistant to the infection because their ACE2 is incompatible with the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. Methods: We generated a mouse-adapted strain SARS-CoV-2 by serial passages in the lung of BALB/c mice. Complete genome deep sequencing of different generations of viruses was performed to characterize the dynamics of the adaptive mutations in SARS-CoV-2. Indirect immunofluorescence analysis and Biolayer interferometry experiments demonstrated that two mutations in RBD significantly increased its binding affinity towards mouse ACE2. Significantly, TLR7/8 agonist Resiquimod block SARS-CoV-2 in vitro and in vivo. Findings: We adapted a wild-type SARS-CoV-2 by serial passages in the lung of BALB/c mice. The mouse-adapted strain WBP-1 showed increased infectivity in BALB/c mice and led to severe interstitial pneumonia. We characterized the dynamics of the adaptive mutations in SARS-CoV-2 and demonstrated that Q493K and Q498H in RBD significantly increased its binding affinity towards mouse ACE2. Additionally, The TLR7/8 agonist Resiquimod was able to protect mice against WBP-1 challenge, demonstrating this mouse-adapted strain is a useful tool to investigate COVID-19 and develop new therapies. Interpretation: We found for the first time that the Q493K and Q498H mutations in the RBD of WBP-1 enhanced its interactive affinities with mACE2. The mouse-adapted SARS-CoV-2 provides a valuable tool for the evaluation of novel antiviral and vaccine strategies, especially in determining the immunopathological consequences of any intervention. This study also verified the antiviral activity of TLR7/8 agonist Resiquimod against SARS-CoV-2 in vitro and in vivo.Funding Statement: This research was funded by Emergency Science and Technology Project of Hubei Province(2020FCA046)and Independent Science and Technology Innovation Fund of Huazhong Agricultural University in 2020 (2662020PY002).Declaration of Interests: The authors declare no competing interests.Ethics Approval Statement: The animal experiments were approved by the Research Ethics Committee, Huazhong Agricultural University, Hubei, China (HZAUMO-2020-0007). All the animal experiments were conducted in accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals from the Research Ethics Committee, Huazhong Agricultural University, Hubei, China.

6.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-312200

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) is often accompanied by gastrointestinal symptoms, which is related to gut microbiota dysbiosis (GMD). Whether washed microbiota transplantation (WMT) is effective in COVID-19 patients suspected with GMD by restoring gut microbiota is unknown. This study is designed to explore the efficacy and safety of WMT in COVID-19 patients suspected with GMD.METHODS: COVID-19 patients suspected with GMD will be randomly divided to receive routine treatment (group A) or receive routine treatment and WMT (group B). The frequency of WMT will be once a day for three consecutive days. Nucleic acid test, imaging examination, and tests related to organ functions, homeostasis, inflammatory response, intestinal barrier function and immunity will be performed at admission, 1, and 2 weeks after treatment and on the day of discharge. The clinical efficacy and safety of WMT in COVD-19 suspected with GMD and the effects of WMT on the organ function, homeostasis, inflammatory response, intestinal barrier function and immunity of the patients will be evaluated. The primary outcome will be the clinical efficacy, as reflected by the SARS-Cov-2 infection status, gastrointestinal symptoms and the recovery of the disease. The secondary outcomes will be the effects of WMT on the organ function, homeostasis, inflammatory response, intestinal barrier function and immunity of the patients, as well as occurrence of adverse events during WMT.DISCUSSION: In the proposed protocol, WMT is expected to be efficacious and safe for the treatment of COVID-19 patients suspected with GMD, and the therapeutic effect is expected to be associated with the improvement of intestinal barrier function, inflammatory response and immunity. Findings from this study may open up a new way for the prevention and treatment of COVID-19 suspected with GMD.TRIAL REGISTRATION: Chinese Clinical Trial Registry – URL: http://www.chictr.org.cn/index.aspx. Registration number: ChiCTR2000032737. Registered 9 May 2020.

7.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-311009

ABSTRACT

Purpose: To evaluate the clinical features and outcomes of rhabdomyolysis (RM) in patients with COVID-19. Method: A single center retrospective cohort study of 1,014 consecutive hospitalized patients with confirmed COVID-19 at the Huoshenshan hospital in Wuhan, China, between February 17 and April 12, 2020. Results: : The overall incidence of RM was 2.2%. Comparing with patients without RM, patients with RM tended to have a higher risk of deterioration, representing by higher ratio to be admitted to the intensive care unit (ICU) (90.9 % vs 5.3%, P <0.001), and to undergo mechanical ventilation (86.4 % vs 2.7% P <0.001). Compared with patients without RM, patients with RM had laboratory test abnormalities, including indicators of inflammation, coagulation activation and kidney injury. Patients with RM had a higher risk of hospital death ( P < 0.001). Cox proportional hazard regression model confirmed that RM indicators, including peak creatine kinase (CK) >1000 IU/L (HR=6.46, 95% CI: 3.02-13.86), peak serum myoglobin (MYO) >1000 ng/mL (HR=9.85, 95% CI: 5.04-19.28) were independent risk factors for in-hospital death. Additionally, patients with COVID-19 that developed RM tended to have a delayed virus clearance. Conclusion: RM might be an important factor contributing to adverse outcomes of patients with COVID-19. Early detection and effective intervention of RM may help reduce deaths of patients with COVID-19.

8.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-307717

ABSTRACT

The worst-hit area of coronavirus disease 2019 (COVID-19) in China was Wuhan City and its affiliated Hubei Province, where the outbreak has been well controlled. The case fatality rate (CFR) is the most direct indicator to evaluate the hazards of an infectious disease. However, most reported CFR on COVID-19 represent a large deviation from reality. We aimed to establish a more accurate way to estimate the CFR of COVID-19 in Wuhan and Hubei and compare it to the reality. The daily case notification data of COVID-19 from December 8, 2019, to May 1, 2020, in Wuhan and Hubei were collected from the bulletin of the Chinese authorities. The instant CFR of COVID-19 was calculated from the numbers of deaths and the number of cured cases, the two numbers occurred on the same estimated diagnosis dates. The instant CFR of COVID-19 was 1.3%-9.4% in Wuhan and 1.2%-7.4% in Hubei from January 1 to May 1, 2020. It has stabilized at 7.69% in Wuhan and 6.62% in Hubei since early April. The cure rate was between 90.1% and 98.8% and finally stabilized at 92.3% in Wuhan and stabilized at 93.5% in Hubei. The mortality rates were 34.5/100 000 in Wuhan and 7.61/100 000 in Hubei. In conclusion, this approach reveals a way to accurately calculate the CFR, which may provide a basis for the prevention and control of infectious diseases.

9.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327136

ABSTRACT

The widespread SARS-CoV-2 in humans results in the continuous emergence of new variants. Recently emerged Omicron variant with multiple spike mutations sharply increases the risk of breakthrough infection or reinfection, highlighting the urgent need for new vaccines with broad-spectrum antigenic coverage. Using inter-lineage chimera and mutation patch strategies, we engineered a recombinant monomeric spike variant (STFK1628x), which showed high immunogenicity and mutually complementary antigenicity to its prototypic form (STFK). In hamsters, a bivalent vaccine comprised of STFK and STFK1628x elicited high titers of broad-spectrum antibodies to neutralize all 14 circulating SARS-CoV-2 variants, including Omicron;and fully protected vaccinees from intranasal SARS-CoV-2 challenges of either the ancestral strain or immune-evasive Beta variant. Strikingly, the vaccination of hamsters with the bivalent vaccine completely blocked the within-cage virus transmission to unvaccinated sentinels, for either the ancestral SARS-CoV-2 or Beta variant. Thus, our study provides new insights and antigen candidates for developing next-generation COVID-19 vaccines.

10.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-325512

ABSTRACT

Background: The coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 isspreading all over the world.The main symptoms of COVID-19 include fever, cough,fatigue, and myalgia. However, there are few reports onolfactoryand gustatory dysfunctions in patients with COVID-19. Objective: To investigate the incidence of olfactory and gustatory dysfunctions in patients with confirmed COVID-19 infection, in Wuhan, China. Methods: : In this retrospective study,we collected 81 confirmed cases of COVID-19 from the Renmin Hospital of Wuhan University, from February 2020 to March 2020, and analyzed the demographic characteristics, clinical manifestations (including olfactory and gustatory dysfunctions), laboratory findings,and comorbidities. Results: : A total of 81 confirmed COVID-19 patients were enrolledin this study (38 males). The most prevalent symptoms include cough, myalgia, and loss of appetite. On admission, 25 (30.9%) of all patients reported either olfactory dysfunction (OD) or gustatory dysfunction (GD), and 7 (8.6%) reported both OD and GD. 13.6% and 25.9% of allpatients reported OD and GD, respectively. OD and GD were not associated with disease severity. Pearson correlation analysisidentified some factors are positively correlated with OD and GD, including headache or dizziness (r = 0.342, P = 0.002), dark urine (r = 0.256, P = 0.021), IgM titer (r = 0.305, P = 0.01), and diabetes (r = 0.275, P = 0.013). In 81.8% of the cases with OD and 28.6% of the cases with GD, the symptomslasted for at least 1 month after discharge.3.6% of inpatients without OD developed OD after discharge. Conclusion: OD and GDare common in COVID-19.These symptoms appear early during thecourse of disease, and may last for at least 1 month.The incidence of OD and GDisrelated to neurological manifestations, diabetics, and IgM titers.

11.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-325449

ABSTRACT

COVID-19 has outbreaked in Wuhan city, Hubei province of China since December 30 th 2019, and spread nationwide and widely spilled over to other countries around the world that has been declared a public health emergency. However, there is no specific drug for the treatment of the disease. Therefore, identifying effective antiviral drugs to combat the disease is urgently needed. Angiotensin converting enzyme 2 (ACE2) has become the promising target to discovery new antiviral drugs to treat COVID-19, we have attempted to discover novel ACE2 inhibitors through ligand-based virtual screening. Finally, eight compounds were selected and tested ACE2 kinase inhibitory assay using fluorescence assays method. The results showed that four compounds (monoammonium glycyrrhizinate, glycyrrhizic acid methyl ester, ginsenoside Rg6 and ginsenoside F1) from 101 kinds of Chinese medicinal and edible plants which could inhibit ACE2 activity in vitro. Further efforts on chemical modification of these lead compounds are undergoing can lead to discover better agents against COVID-19.

12.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-323685

ABSTRACT

Background: The coronavirus disease 2019 (COVID-19) has spread worldwide, leading to thousands of deaths. We aim to describe the epidemiological and clinical characteristics of patients with coronavirus disease 2019 (COVID-19) in Fujian province, China. Methods In this retrospective, multi-center study, we collected and analysed 165 patients of COVID-19 confirmed by real time PCR of nasopharyngeal swab specimens in five tertiary hospitals of Fujian province, China from Jan 22 to Feb 16, 2020. The final date of follow-up was February 21, 2020. Results Of the 165 hospitalized patients with COVID-19, 101 patients had relation with Wuhan within two weeks. Symptoms at illness onset mainly were fever (76.4%), cough (60%) and expectoration (38.2%). On admission, the severity of most patients were classified as mild or common and lymphopenia (33.9%), hypoxemia (15.2%), elevated and bilateral pneumonia (83.6%) was observed. Patients older than 65 years had significantly high frequency of hypertension, diabetes, severe classification, lymphopenia and hypoxemia than those younger than 65 years. Age correlated negatively with lymphocyte count and oxygenation index on admission while positively with duration from exposure to the time of negative RT-PCR. At the end of follow-up, 80 patients were discharged and one died. The median hospital stay was 17 days. Conclusions Patients with COVID-19 were mostly non-severe cases in Fujian province and older patients (>65 years) were more likely to have lymphopenia and hypoxemia, and to progress as severe cases of COVID-19 than those younger than 65.

13.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-323544

ABSTRACT

The coronavirus disease-19 (COVID-19) caused by SARS-CoV-2 infection can lead to a series of clinical settings from non-symptomatic viral carriers/spreaders to severe illness characterized by acute respiratory distress syndrome (ARDS)1,2. A sizable part of patients with COVID-19 have mild clinical symptoms at the early stage of infection, but the disease progression may become quite rapid in the later stage with ARDS as the common manifestation and followed by critical multiple organ failure, causing a high mortality rate of 7-10% in the elderly population with underlying chronic disease1-3. The pathological investigation in the lungs and other organs of fatal cases is fundamental for the mechanistic understanding of severe COVID-19 and the development of specific therapy in these cases. Gross anatomy and molecular markers allowed us to identify, in two fatal patients subject to necropsy, the main pathological features such as exudation and hemorrhage, epithelium injuries, infiltration of macrophages and fibrosis in the lungs. The mucous plug with fibrinous exudate in the alveoli and the activation of alveolar macrophages were characteristic abnormalities. These findings shed new insights into the pathogenesis of COVID-19 and justify the use of interleukin 6 (IL6) receptor antagonists and convalescent plasma with neutralizing antibodies against SARS-CoV-2 for severe patients.Authors Chaofu Wang, Jing Xie, Lei Zhao, Xiaochun Fei, Heng Zhang, and Yun Tan contributed equally to this work. Authors Chaofu Wang, Jun Cai, Rong Chen, Zhengli Shi, and Xiuwu Bian jointly supervised this work.

14.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-293751

ABSTRACT

Background: Since December 2019, a novel coronavirus (2019-nCoV) associated pneumonia has emerged in Wuhan, China. The study aimed to further clarify the epidemiological and clinical characteristics of 2019-nCoV pneumonia.<br><br>Methods: 99 cases admitted to Wuhan Jinyintan Hospital during January 1 to 20, 2020 and confirmed by real-time reverse-transcriptase polymerase-chain-reaction (RT-PCR) test were analyzed for epidemiological, demographic, clinical, radiological features, and laboratory data. <br><br>Findings: Of the 99 patients with 2019-nCoV pneumonia, 49 (49%) had a history of exposure to the South China Seafood Wholesale Market. The average age of the patients was 62.85 ± 11.99 years, including 67 males and 32 females. 2019-nCoV was detected in all patients by RT-PCR, and some of them also by serological testing, and metagenomics sequencing analysis. 50 cases (50.51%) had chronic basic diseases. Patients had clinical manifestations of fever (83%), cough (82%), shortness of breath (31%), muscle aches (11%), headache (8%), fuzzy confusion (7%), chest pain (2%), and diarrhea (2%). According to imaging examination, 74 patients showed bilateral pneumonia (74.75%), 25 patients showed multiple mottled and ground-glass opacity, and 1 patient had pneumothorax. Most patients received antiviral, antibiotics, supportive treatments, continuous renal replacement therapy (CRRT) and extracorporeal membrane oxygenation (ECMO), and had good prognosis. 17 patients developed acute Respiratory Distress Syndrome (ARDS) and among them, 2 patients worsened in a short period of time and died of multiple organ failure.<br><br>Interpretation: The infection of the 2019-nCoV can result in severe and even fatal respiratory disease like ARDS. It is very important to actively prevent complications and secondary infections, treat underlying diseases, and provide timely organ function support. Early diagnosis, early isolation, multiple treatment, and intervention of CRRT and ECMO when necessary can effectively reduce mortality caused by severe coronavirus pneumonia.<br><br>Funding: National Key R&D Program of China (No. 2017YFC1309700)<br><br>Declaration of Interest: The author reports no conflicts of interest in this work.<br><br>Ethical Approval: The study was approved by Jinyintan Hospital Ethics Committee and written informed consent was obtained from all patients involved before enrolment.

15.
Non-conventional in English | [Unspecified Source], Grey literature | ID: grc-750489

ABSTRACT

SARS-CoV-2 has emerged as a global pathogen, sparking urgent vaccine development efforts with the trimeric spike. However, the inability of antibodies like CR3022, which binds a cryptic spike epitope with nanomolar affinity, to neutralize virus, suggests a spike-based means of neutralization escape. Here, we show the SARS-CoV-2 spike to have 10% the unfolding enthalpy of a globular protein at physiological pH, where it is recognized by antibodies like CR3022, and up to 10-times more unfolding enthalpy at endosomal pH, where it sheds such antibodies, suggesting that the spike evades potentially neutralizing antibody through a pH-dependent mechanism of conformational masking. To understand the compatibility of this mechanism with ACE2-receptor interactions, we carried out binding measurements and determined cryo-EM structures of the spike recognizing up to three ACE2 molecules at both physiological and endosomal pH. In the absence of ACE2, cryo-EM analyses indicated lower pH to reduce conformational heterogeneity. Single-receptor binding domain (RBD)-up conformations dominated at pH 5.5, resolving into a locked all-down conformation at lower pH through lowering of RBD and refolding of a pH-dependent switch. Notably, the emerging Asp614Gly strain partially destabilizes the switch that locks RBD down, thereby enhancing functional interactions with ACE2 while reducing evasion by conformational masking.

16.
Geophysical Research Letters ; n/a(n/a):e2021GL092987, 2021.
Article in English | Wiley | ID: covidwho-1287793

ABSTRACT

AbstractThe impacts of anthropogenic emissions on the reduction of source-specific equivalent black carbon (eBC) aerosols and their direct radiative effects (DREs) were investigated during the lockdown of the coronavirus outbreak in a megacity of China in 2020. Five eBC sources were identified using a hybrid environmental receptor model. Results showed that biomass burning, traffic-related emissions, and coal combustion were the dominant contributors to eBC. The generalized additive model indicated that the reduction of traffic-related eBC during the lockdown was entirely attributed to the decrease of emissions. Decreased biomass-burning activities and favorable meteorological factors are both important drivers for the biomass-burning eBC reduction during the lockdown. A radiative transfer model showed that the DRE efficiency of eBC from biomass burning was the strongest, followed by coal combustion and traffic-related emissions. This study highlights that aggressive reduction in the consumption of residential solid fuels would be effective in achieving climate change mitigation.

18.
Preprint in English | bioRxiv | ID: ppbiorxiv-402677

ABSTRACT

SARS-CoV-2 infection takes a mild or clinically inapparent course in the majority of humans who contract this virus. After such individuals have cleared the virus, only the detection of SARS-CoV-2-specific immunological memory can reveal the exposure, and hopefully the establishment of immune protection. With most viral infections, the presence of specific serum antibodies has provided a reliable biomarker for the exposure to the virus of interest. SARS-CoV-2 infection, however, does not reliably induce a durable antibody response, especially in sub-clinically infected individuals. Consequently, it is plausible for a recently infected individual to yield a false negative result within only a few months after exposure. Immunodiagnostic attention has therefore shifted to studies of specific T cell memory to SARS-CoV-2. Most reports published so far agree that a T cell response is engaged during SARS-CoV-2 infection, but they also state that in 20-81% of non-SARS-CoV-2-exposed individuals, T cells respond to SARS-CoV-2 antigens (mega peptide pools), allegedly due to T cell cross-reactivity with coronaviruses causing Common Cold (CCC), or other antigens. Here we show that by introducing irrelevant mega peptide pools as negative controls to account for chance cross-reactivity, and by establishing the antigen dose-response characteristic of the T cells, one can clearly discern between cognate T cell memory induced by SARS-CoV-2 infection vs. cross-reactive T cell responses in individuals who had not been infected with SARS-CoV-2.

19.
SciFinder; 2020.
Preprint | SciFinder | ID: ppcovidwho-2016

ABSTRACT

The study analyzes the clin. characteristics of coronavirus disease 2019 (COVID-19) in patients on maintenance hemodialysis. The clin. characteristics of COVID-19 are similar to thoseof common viral pneumonia. High resolution CT is of great value in the differential diagnosis of this disease. Continuous renal replacement therapy (CRRT) in the isolation ward can prevent the spread COVID-19.

20.
SSRN; 2020.
Preprint | SSRN | ID: ppcovidwho-711

ABSTRACT

Background: The outbreak of the coronavirus disease 2019 (COVID-19) in China has been basically controlled. However, the worldwide COVID-19 cases are increasing

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