ABSTRACT
Objective: We sought to investigate the clinical characteristics of patients with novel coronavirus pneumonia in Xiamen, which is a city in Fujian Province, China. Methods: From January 20, 2020, to March 4, 2020, the clinical characteristics of all patients confirmed with novel coronavirus pneumonia admitted to the First Affiliated Hospital of Xiamen University, which was the only designated hospital for cases of novel coronavirus pneumonia in Xiamen, were analyzed. Results: A total of 35 cases of novel coronavirus pneumonia were confirmed. Patients were divided into the general-ward admission group and the intensive-care-unit (ICU) admission group. The most commonly observed symptoms were fever (80%), cough (51%), expectoration (28%), and fatigue (23%). Compared with patients in the general-ward group, patients in the ICU group had a higher maximum body temperature, a longer duration of fever after admission, and more symptoms of systemic pain. Considering the laboratory findings, patients in the ICU group exhibited lower peripheral blood lymphocyte ratios and lymphocyte counts but higher C-reactive protein and lactate dehydrogenase levels. All patients were discharged without death, and no patients required invasive ventilation, continuous renal replacement therapy, or extracorporeal membrane oxygenation. Conclusion: Relative to patients with novel coronavirus pneumonia in Wuhan, the cases in Xiamen were less severe.
Subject(s)
Coronavirus Infections , Fever , Pain , FatigueABSTRACT
The global pandemic of Coronavirus disease 2019 (COVID-19) is a disaster for human society. A convenient and reliable in vitro neutralization assay is very important for the development of neutralizing antibodies, vaccines and other inhibitors. In this study, G protein-deficient vesicular stomatitis virus (VSVdG) bearing full-length and truncated spike (S) protein of SARS-CoV-2 were evaluated. The virus packaging efficiency of VSV-SARS-CoV-2-Sdel18 (S with C-terminal 18 amino acid truncation) is much higher than VSV-SARS-CoV-2-S. A neutralization assay for antibody screening and serum neutralizing titer quantification was established based on VSV-SARS-CoV-2-Sdel18 pseudovirus and human angiotensin-converting enzyme 2 (ACE2) overexpressed BHK21 cell (BHK21-hACE2). The experimental results can be obtained by automatically counting EGFP positive cell number at 12 hours after infection, making the assay convenient and high-throughput. The serum neutralizing titer of COVID-19 convalescent patients measured by VSV-SARS-CoV-2-Sdel18 pseudovirus assay has a good correlation with live SARS-CoV-2 assay. Seven neutralizing monoclonal antibodies targeting receptor binding domain (RBD) of SARS-CoV-2-S were obtained. This efficient and reliable pseudovirus assay model could facilitate the development of new drugs and vaccines.
Subject(s)
COVID-19 , Vesicular StomatitisABSTRACT
Background Timely diagnosis of SARS-CoV-2 infection is the prerequisite for treatment and preventive quarantine. The serology characteristics and complement diagnosis value of antibody test to RNA test needs to be demonstrated. Method A patient cohort study was conducted at the first affiliated hospital of Zhejiang University, China. Serial sera of COVID-19 patients were collected and total antibody (Ab), IgM and IgG antibody against SARS-CoV-2 were detected. The antibody dynamics during the infection were described. Results The seroconversion rate for Ab, IgM and IgG in COVID-19 patients was 98.8% (79/80), 93.8% (75/80) and 93.8% (75/80), respectively. The first detectible serology marker is total antibody and followed by IgM and IgG, with a median seroconversion time of 15, 18 and 20 day post exposure (d.p.e) or 9, 10 and 12 days post onset, separately. The antibody levels increased rapidly since 6 d.p.o and accompanied with the decline of viral load. For patients in the early stage of illness (0-7d.p.o),Ab showed the highest sensitivity (64.1%) compared to the IgM and IgG (33.3% for both, p<0.001). The sensitivities of Ab, IgM and IgG detection increased to 100%, 96.7% and 93.3% two weeks later, respectively. Conclusions Typical acute antibody response is induced during the SARS-CoV-2 infection. The serology testing provides important complementation to RNA test for pathogenic specific diagnosis and helpful information to evaluate the adapted immunity status of patient. It should be strongly recommended to apply well-validated antibody tests in the clinical management and public health practice to improve the control of COVID-19 infection.