ABSTRACT
The coronaviruses (CoVs) are positive-sense, single-stranded, non-segmented enveloped RNA viruses. The family is known as Coronaviridae. CoV gets its name from the spike protein on its surface, which resembles the solar corona. 10% to 30% of seasonal cold cases are thought to be caused by the 229E alpha CoV, NL63 alpha CoV, OC43 beta CoV, and HKU1 beta CoV strains. After the Middle Eastern respiratory syndrome coronavirus (MERS-CoV) in 2012 and the severe acute respiratory syndrome coronavirus (SARS-CoV) in 2002, another zoonotic coronavirus known as 2019 new CoV (COVID-19) first emerged in Wuhan province, China, presenting as pneumonia of unknown origin. On December 31, 2019, local health authorities issued an epidemiological notice, presuming it had happened after exposure to the fish market. Males make up the majority of the hospitalized patients, and most of them are in their fifth decade of life. Diabetes mellitus, hypertension, cardiovascular disease, and chronic obstructive pulmonary disease were underlying co-morbidities in COVID-19 patients. The most frequent symptom was fever, which was followed by cough, dyspnea, myalgia, and weariness. Diarrhoea, hemoptysis, and headache were among other less frequent symptoms. The development of dyspnea, acute respiratory distress syndrome (ARDS), the necessity for mechanical ventilation, and the demand for intensive care unit (ICU) care all occurred between the time of the disease' commencement and hospitalization, respectively. Important laboratory findings in the patients needing ICU care were leucopenia, a prothrombin time that was extended, and high D-dimer levels at check-in. Troponin I and serum aspartate aminotransferase levels were also measured. The potentially fatal repercussions of epidemics like the current COVID-19 outbreak can be devastating in impoverished nations like India where tertiary health care and ICU care facilities are not generally available, accessible, and inexpensive. There are established criteria for diagnostic testing. If the CoV infections turn into a public health emergency, ICMR has recommended using a combination of lopinavir and ritonavir after receiving authorisation from the Drug Controller General of India. Directives for the prophylaxis of healthcare personnel with hydroxychloroquine have recently been issued. Critical care capacity growth should be long-term planned.
ABSTRACT
Background and Aims: A major limitation to providing oxygen therapy by high flow nasal oxygen (HFNO) delivery devices is its availability and therefore as an alternative many clinicians use a standard non rebreathing face mask (NRBM) in order to oxygenate their patients where low-flow nasal oxygen or simple facemask oxygen is not providing adequate respiratory support to achieve the target peripheral oxygen saturation (SpO2). We aimed to determine the clinical effectiveness of HFNO versus NRBM in terms of improving patient outcome among patients admitted to our intensive care unit (ICU) during coronavirus disease-2019 (COVID-19) outbreak. Methods: In this prospective open labelled study, 122 COVID-19 patients presenting with acute hypoxaemic respiratory failure (AHRF) were randomised to receive either HFNO or NRBM to achieve the target SpO2. The primary clinical outcome measured was device failure rate and secondary outcome was all-cause 28-day mortality rate. Results: The device failure rate was significantly higher in HFNO group (39% versus 21%, P = 0.030). Oxygen support with NRBM resulted in a reduced all mortality rate over HFNO (26.2% versus 45%) but the mortality rate after treatment failure in either group (HFNO or NRBM) remained high (91% versus 92%). Conclusion: Oxygen support with NRBM results in both reduced device failure rate and higher survival among patients of COVID-19 with AHRF.
ABSTRACT
PURPOSE: A large number of new molecular or virology laboratories have been established to increase the testing capacity for SARS-CoV-2. Due to heavy workload, there is delay in testing of samples. In order to avoid the negative effect of delayed testing on RTPCR results guidelines are issued from WHO and CDC to transport samples in cold chain. However, in pandemic situations the recommended guidelines for transport and storage conditions are often compromised. This study was conducted to evaluate the effect of sample storage conditions at different temperatures on the results of RT PCR test. METHODS: Total 275 samples were included in this study, among these 126 samples tested positive and 149 samples tested negative. All samples were aliquoted into two and the aliquotes stored in duplicate at 4 â°C and room temperature. All aliquots stored at both the temperatures were tested by RTPCR every 24 hours up to 5 days. RESULTS: Diagnostic accuracy decreased from day1 to day 5 at both the storage temperatures i,e 4 â°C and room temperature in comparison to the initial day results. Positivity decreased on an average of 9.02% at 4 â°C and at 9.27% at room temperature per day. Among total 126 positive samples on an average false negative and failure of internal control at 4 â°C and room temperature was 8.86%, 8.22% and 3.64%, and 4.12%, respectively. All the samples with CT value â< â30 remained positive at both temperatures up to 5 days. Few samples with >30 CT value showed variable results i.e. positive, negative or internal control failure from day 1 (2nd day after sample collection) onwards. CONCLUSIONS: There was no significant difference between RT PCR results of samples stored at 4 â°C and room temperature up to 5 days of collection. However internal control failure was more in samples stored at room temperature. Therefore, samples received without cold chain also may be processed by RTPCR and should not be rejected.
Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnosis , COVID-19 Testing , Humans , Pandemics , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2/genetics , Specimen Handling/methods , TemperatureABSTRACT
Past experiments demonstrated SARS-CoV-2 inactivation by simulated sunlight; models have considered exclusively mechanisms involving UVB acting directly on RNA. However, UVA inactivation has been demonstrated for other enveloped RNA viruses, through indirect mechanisms involving the suspension medium. We propose a model combining UVB and UVA inactivation for SARS-CoV-2, which improves predictions by accounting for effects associated with the medium. UVA sensitivities deduced for SARS-CoV-2 are consistent with data for SARS-CoV-1 under UVA only. This analysis calls for experiments to separately assess effects of UVA and UVB in different media, and for including UVA in inactivation models. Key words: SARS-CoV-2, COVID-19, environmental persistence, sunlight, UVA, UVB, modeling, inactivation methods, photobiology
Subject(s)
COVID-19ABSTRACT
SARS-CoV-2 is a betacoronavirus, the etiologic agent of the novel Coronavirus disease 2019 (COVID-19). In December 2019, an outbreak of COVID-19 began in Wuhan province of the Hubei district in China and rapidly spread across the globe. On March 11th, 2020, the World Health Organization officially designated COVID-19 as a pandemic. Across the continents and specifically in Africa, all index cases were travel related. Thus, it is crucial to compare COVID-19 genome sequences from the African continent with sequences from COVID-19 hotspots (including China, Brazil, Italy, United State of America and the United Kingdom). To identify if there are distinguishing mutations in the African SARS-CoV-2 genomes compared to genomes from other countries, including disease hotspots, we conducted in silico analyses and comparisons. Complete African SARS-CoV-2 genomes deposited in GISAID and NCBI databases as of June 2020 were downloaded and aligned with genomes from Wuhan, China and other SARS-CoV-2 hotspots. Using phylogenetic analysis and amino acid sequence alignments of the spike and replicase (NSP12) proteins, we searched for possible targets for vaccine coverage or potential therapeutic agents. Our results showed a similarity between the African SARS-CoV-2 genomes and genomes in countries including China, Brazil, France, the United Kingdom, Italy, France and the United States of America. This study shows for the first time, an in-depth analysis of the SARS-CoV-2 landscape across Africa and will potentially provide insights into specific mutations to relevant proteins in the SARS-CoV-2 genomes in African populations.
Subject(s)
COVID-19ABSTRACT
To contain the coronavirus disease 2019 (COVID-19) pandemic, a safe and effective vaccine against the new severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is urgently needed in quantities sufficient to immunise large populations. In this study, we report the design, preclinical development, immunogenicity and anti-viral protective effect in rhesus macaques of the BNT162b2 vaccine candidate. BNT162b2 contains an LNP-formulated nucleoside-modified mRNA that encodes the spike glycoprotein captured in its prefusion conformation. After expression of the BNT162b2 coding sequence in cells, approximately 20% of the spike molecules are in the one-RBD up, two-RBD down state. Immunisation of mice with a single dose of BNT162b2 induced dose level-dependent increases in pseudovirus neutralisation titers. Prime-boost vaccination of rhesus macaques elicited authentic SARS-CoV-2 neutralising geometric mean titers 10.2 to 18.0 times that of a SARS-CoV-2 convalescent human serum panel. BNT162b2 generated strong TH1 type CD4+ and IFNy+ CD8+ T-cell responses in mice and rhesus macaques. The BNT162b2 vaccine candidate fully protected the lungs of immunised rhesus macaques from infectious SARS-CoV-2 challenge. BNT162b2 is currently being evaluated in a global, pivotal Phase 2/3 trial (NCT04368728).
Subject(s)
Coronavirus Infections , COVID-19ABSTRACT
Objectives: SARS-CoV-2 infection is the cause of a worldwide pandemic, currently with limited therapeutic options. It is characterised by being highly contagious and nasal mucosa appears to be the primary site with subsequent spread to the lungs and elsewhere. BromAc (Bromelain & Acetylcysteine) has been described to disrupt glycoproteins by the synchronous breakage of glycosidic linkages and disulphide bonds. The spike protein of SARS-CoV-2 is an attractive target as it is essential for binding to the ACE2 receptor in host cells and is formed of glycoprotein and disulphide bridges for stabilisation. Hence, we sought to determine whether BromAc has activity on the spike and envelope protein specific to SARS-CoV-2 virus. Design: Gel electrophoresis analysis was carried out on recombinant spike and envelope proteins that were treated with a range of concentrations of single agents and BromAc. For UV analysis of disulfide bonds reduction, both spike and envelope protein were treated with Acetylcysteine with the determination of loss of disulfide bonds. Results: Recombinant spike and envelope SARS-CoV-2 protein were fragmented by BromAc whilst single agents had minimal effect. Spike and envelope proteins disulphide bonds were reduced by Acetylcysteine. Conclusion: BromAc disintegrates the spike and envelope protein from SARS-CoV-2 and may render it non-infective. In vitro tests on live virus have been encouraging and clinical testing through nasal administration in patients with early SARS-CoV-2 infection is imminent.
Subject(s)
COVID-19ABSTRACT
ObjectivesConvalescent plasma (CP) as a passive source of neutralizing antibodies and immunomodulators is a century-old therapeutic option used for the management of viral diseases. We investigated its effectiveness for the treatment of COVID-19. DesignOpen-label, parallel-arm, phase II, multicentre, randomized controlled trial. SettingThirty-nine public and private hospitals across India. ParticipantsHospitalized, moderately ill confirmed COVID-19 patients (PaO2/FiO2: 200-300 or respiratory rate > 24/min and SpO2 [≤] 93% on room air). InterventionParticipants were randomized to either control (best standard of care (BSC)) or intervention (CP + BSC) arm. Two doses of 200 mL CP was transfused 24 hours apart in the intervention arm. Main Outcome MeasureComposite of progression to severe disease (PaO2/FiO2< 100) or all-cause mortality at 28 days post-enrolment. ResultsBetween 22nd April to 14th July 2020, 464 participants were enrolled; 235 and 229 in intervention and control arm, respectively. Composite primary outcome was achieved in 44 (18.7%) participants in the intervention arm and 41 (17.9%) in the control arm [aOR: 1.09; 95% CI: 0.67, 1.77]. Mortality was documented in 34 (13.6%) and 31 (14.6%) participants in intervention and control arm, respectively [aOR) 1.06 95% CI: -0.61 to 1.83]. InterpretationCP was not associated with reduction in mortality or progression to severe COVID-19. This trial has high generalizability and approximates real-life setting of CP therapy in settings with limited laboratory capacity. A priori measurement of neutralizing antibody titres in donors and participants may further clarify the role of CP in management of COVID-19. Trial registrationThe trial was registered with Clinical Trial Registry of India (CTRI); CTRI/2020/04/024775.
Subject(s)
COVID-19ABSTRACT
Convalescent plasma from SARS-CoV-2 infected individuals and monoclonal antibodies were shown to potently neutralize viral and pseudoviral particles carrying the S glycoprotein. However, a non-negligent proportion of plasma samples from infected individuals as well as S-specific monoclonal antibodies were reported to be non-neutralizing despite efficient interaction with the S glycoprotein in different biochemical assays using soluble recombinant forms of S or when expressed at the cell surface. How neutralization relates to binding of S glycoprotein in the context of viral particles remains to be established. Here we developed a pseudovirus capture assay (VCA) to measure the capacity of plasma samples or antibodies immobilized on ELISA plates to bind to membrane-bound S glycoproteins from SARS-CoV-2 expressed at the surface of lentiviral particles. By performing VCA and neutralization assays we observed a strong correlation between these two parameters. However, while we found that plasma samples unable to capture viral particles did not neutralize, capture did not guarantee neutralization, indicating that the capacity of antibodies to bind to the S glycoprotein at the surface of viral particles is required but not sufficient to mediate neutralization. Altogether, our results highlights the importance of better understanding the inactivation of S by plasma and neutralizing antibodies.
Subject(s)
Severe Acute Respiratory SyndromeABSTRACT
A novel severe acute respiratory (SARS)-like coronavirus (SARS-CoV-2) is responsible for the current global coronavirus disease 2019 (COVID-19) pandemic, infecting millions of people and causing hundreds of thousands of deaths. The viral entry of SARS-CoV-2 depends on an interaction between the receptor binding domain of its trimeric Spike glycoprotein and the human angiotensin converting enzyme 2 (ACE2) receptor. A better understanding of the Spike/ACE2 interaction is still required to design anti-SARS-CoV-2 therapeutics. Here, we investigated the degree of cooperativity of ACE2 within both the SARS-CoV-2 and the closely related SARS-CoV-1 membrane-bound S glycoproteins. We show that there exist differential inter-protomer conformational transitions between both Spike trimers. Interestingly, the SARS-CoV-2 spike exhibits a positive cooperativity for monomeric soluble ACE2 binding when compared to the SARS-CoV-1 spike, which might have more structural restrains. Our findings can be of importance in the development of therapeutics that block the Spike/ACE2 interaction.