ABSTRACT
In this report, we describe four RT-qPCR assays that enable rapid identification of the newly emerging SARS-COV-2 Omicron (B.1.1.529) variant of concern. The assays target Omicron characteristic mutations in the nsp6 (Orf1a), spike and nucleocapsid genes. We demonstrate that the assays are straightforward to assemble and perform, are amendable for multiplexing, and may be used as a reliable first-line tool to identify B.1.1.529 suspected samples. Importantly, this is a preliminary development report. Further validation and optimization of the assays described herein will be published hereafter.
ABSTRACT
Severe manifestations of COVID-19 are mostly restricted to persons with comorbidities, and they form a significantly high proportion of those which develop life-endangering lung injury. Nevertheless, COVID-19 animal models established to date are not based on preexistence of comorbidities. Here we report that mild pulmonary injury induced by administration of acute-lung-injury stimulants, renders outbred CD-1 mice to be sensitive to SARS-CoV-2. Following intranasal pretreatment of mice with low doses of ricin or bleomycin, SARS-CoV-2 infection caused a severe disease manifested by sustained body loss and mortality rates of >50%. Low-dose-ricin pretreated mice displayed markedly higher levels of viral RNA than mice not pretreated with ricin, not only in the nasal turbinate, trachea and lungs but also in the serum and heart. The deleterious effects of SARS-CoV-2 infection in ricin-pretreated mice were effectively alleviated by passive transfer of polyclonal and monoclonal antibodies generated against SARS-CoV-2 or SARS-CoV-2 RBD. Notably, viral cell entry in the sensitized mice model seems to involve viral RBD binding, albeit by a mechanism other than the canonical ACE2-mediated uptake route. In summary, we present a novel animal model in mice that express native murine ACE2 yet are susceptible to genetically unaltered SARS-CoV-2, for the study of comorbidity-dependent COVID-19 pathology and treatment.
Subject(s)
Pulmonary Embolism , Lung Diseases , Tracheomalacia , Acute Lung Injury , COVID-19ABSTRACT
This study describes the development of a novel assay for SARS-CoV-2 identification using LC-MS/MS analysis. A multi-step procedure for the rational down-selection of a set of markers has leaded to the discovery of six SARS-CoV-2 specific and sensitive markers, enabling the reliable identification of the virus. A rapid and simple assay was developed, successfully applied to clinical nasopharyngeal samples. The assay may potentially serve as a complementary approach for SARS-CoV-2 identification.
ABSTRACT
The COVID-19 pandemic caused by SARS-CoV-2 that emerged in December 2019 in China resulted in over 7.8 million infections and over 430,000 deaths worldwide, imposing an urgent need for rapid development of an efficient and cost-effective vaccine, suitable for mass immunization. Here, we generated a replication competent recombinant VSV-{Delta}G-spike vaccine, in which the glycoprotein of VSV was replaced by the spike protein of the SARS-CoV-2. In vitro characterization of the recombinant VSV-{Delta}G-spike indicated expression and presentation of the spike protein on the viral membrane with antigenic similarity to SARS-CoV-2. A golden Syrian hamster in vivo model for COVID-19 was implemented. We show that vaccination of hamsters with recombinant VSV-{Delta}G-spike results in rapid and potent induction of neutralizing antibodies against SARS-CoV-2. Importantly, single-dose vaccination was able to protect hamsters against SARS-CoV-2 challenge, as demonstrated by the abrogation of body weight loss of the immunized hamsters compared to unvaccinated hamsters. Furthermore, whereas lungs of infected hamsters displayed extensive tissue damage and high viral titers, immunized hamsters lungs showed only minor lung pathology, and no viral load. Taken together, we suggest recombinant VSV-{Delta}G-spike as a safe, efficacious and protective vaccine against SARS-CoV-2 infection.