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1.
J Med Virol ; 2022 Jan 08.
Article in English | MEDLINE | ID: covidwho-1611315

ABSTRACT

The recently emerging SARS-CoV-2 variant omicron displays an unusual association of 30 mutations, 3 deletions and 1 insertion. To analyze the impact of this atypic mutational landscape, we constructed a complete structure of the Omicron spike protein. Compared with the delta variant, the receptor binding domain (RBD) of omicron has an increased electrostatic surface potential, but a decreased affinity for the ACE-2 receptor. The N-terminal domain (NTD) has both a decreased surface potential and a lower affinity for lipid rafts. The omicron variant is predicted to be less fusogenic and thus less pathogenic than delta, due to a geometric reorganization of the S1-S2 cleavage site. Overall, these virological parameters suggest that omicron does not have a significant infectivity advantage over the delta variant. However, in omicron, neutralizing epitopes are greatly affected, suggesting that current vaccines will probably confer little protection against this variant. In conclusion, the puzzling mutational pattern of the omicron variant combines contradictory properties which may either decrease (virological properties) or increase (immunological escape/facilitation) the transmission of this variant in the human population. This Janus-like phenotype may explain some conflicting reports on the initial assessment of omicron and provides new insights about the molecular mechanisms controlling its dissemination and pathogenesis worldwide. This article is protected by copyright. All rights reserved.

2.
BMJ Open ; 11(12), 2021.
Article in English | ProQuest Central | ID: covidwho-1591339

ABSTRACT

ObjectiveBetween 1 March and 15 June, France experienced the first wave of the COVID-19 pandemic, during which 29 549 deaths occurred among COVID-19 patients, 17 250 of whom died in hospital. Our hypothesis is that crude mortality rates are not sufficient to assess the impact of the epidemic on public health. The objective of this paper is to estimate the potential years of life lost (YLL) of patients who died from COVID-19.MethodWe realised a retrospective analysis of the exhaustive sample of COVID-19 PCR-positive patients who died in public hospitals of Marseille during this first wave. Data on demographic characteristics, comorbidities and care pathways were collected from medical records. The Charlson Comorbidity Index (CCI) was used to assess what would have been the probability of dying within 1 year of these patients in the absence of COVID-19 and to estimate total YLL.ResultsAmong the 1631 patients who were hospitalised for COVID-19, 178 patients died, at an average age of 80 years. According to CCI, 88.8% of the deceased patients had an 85% probability of dying within 1 year before COVID-19. Among the 11.2% who had a lower CCI probability, 18 out of 20 had at least one additional comorbidity known to be a major risk factor of mortality in COVID-19 disease. Cumulative total number of YLL was estimated to be 541 in this deceased population, that is, an average of 3 YLL.ConclusionAlthough our results should be interpreted with caution, this analysis confirms that mortality due to COVID-19 translates into a limited number of YLL due to both old age and preexisting comorbidities in the most vulnerable patients. This fact should be better considered in public health management of the pandemic both for risk communication and design of the most appropriate protective measures.

4.
Future Microbiol ; 16: 1341-1370, 2021 11.
Article in English | MEDLINE | ID: covidwho-1555047

ABSTRACT

Since the beginning of the COVID-19 pandemic, large in silico screening studies and numerous in vitro studies have assessed the antiviral activity of various drugs on SARS-CoV-2. In the context of health emergency, drug repurposing represents the most relevant strategy because of the reduced time for approval by international medicines agencies, the low cost of development and the well-known toxicity profile of such drugs. Herein, we aim to review drugs with in vitro antiviral activity against SARS-CoV-2, combined with molecular docking data and results from preliminary clinical studies. Finally, when considering all these previous findings, as well as the possibility of oral administration, 11 molecules consisting of nelfinavir, favipiravir, azithromycin, clofoctol, clofazimine, ivermectin, nitazoxanide, amodiaquine, heparin, chloroquine and hydroxychloroquine, show an interesting antiviral activity that could be exploited as possible drug candidates for COVID-19 treatment.


Subject(s)
Antiviral Agents/therapeutic use , COVID-19/drug therapy , Middle East Respiratory Syndrome Coronavirus/drug effects , SARS-CoV-2/drug effects , Animals , COVID-19/virology , Cell Line , Chlorocebus aethiops , Drug Repositioning/methods , Humans , Molecular Docking Simulation , Pandemics/prevention & control , Vero Cells
6.
Virus Genes ; 2021 Nov 27.
Article in English | MEDLINE | ID: covidwho-1536341

ABSTRACT

Great concerns have been raised about SARS-CoV-2 variants over the past six months. At the end of 2020, an increasing incidence of spike substitutions Q677H/P was described in the USA, which involved six independent lineages. We searched for changes to this amino acid in the sequence database of SARS-CoV-2 genomes obtained at the IHU Méditerranée Infection (Marseille, France) from 3634 patients sampled between February 2020 and April 2021. In seven genomes (0.2%), we found a deletion of five amino acids at spike positions 675-679 (QTQTN) including Q677, and in 76 genomes (2.3%) we found a Q677H substitution. The 83 genomes were classified in ten different Pangolin lineages. Genomes with a spike Q677 deletion were obtained from respiratory samples collected in six cases between 28 March 2020 and 12 October 2020 and in one case on 1 February 2021. The Q677H substitution was found in genomes all obtained from respiratory samples collected from 19 January 2021 and were classified in seven different lineages. Most of these genomes (41 cases) were of UK variant. Two others were classified in the B.1.160 Pangolin lineage (Marseille-4 variant) which was first detected in July 2020 in our institute but was devoid of this substitution until 19 January 2021. Also, eight genomes were classified in the A.27/Marseille-501 lineage which was first detected in our institute in January 2021 and which either harboured or did not harbour the Q677H substitution. Thus, the spike Q677H substitution should be considered as another example of convergent evolution, as it is the case of spike substitutions L18F, E484K, L452R, and N501Y which also independently appeared in various lineages.

7.
Emerg Microbes Infect ; 10(1): 2276-2278, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1522076

ABSTRACT

Culture inoculation of 6722 nasopharyngeal samples since February 2020 allowed isolation of 3637 SARS-CoV-2 and confirmed that isolation rate is correlated to viral load, regardless symptomatology or vaccination status. Moreover, the delta variant is associated with higher viral loads and therefore higher rates of viral isolation, explaining its greater contagiousness.

8.
Viruses ; 13(11)2021 10 28.
Article in English | MEDLINE | ID: covidwho-1488758

ABSTRACT

BACKGROUND: Since the beginning of the COVID-19 pandemic, several SARS-CoV-2 variants have sequentially emerged. In France, most cases were due to spike D641G-harbouring viruses that descended initially from the Wuhan strain, then by the variant of B.1.160 lineage we called Marseille-4 since the summer of 2020, which was followed by the Alpha and Beta variants in early 2021, then the Delta variant currently. METHODS: We determined the neutralising antibody (nAb) titres in sera from convalescent individuals previously infected by these four major local variants and from vaccine recipients to the original Wuhan strain and nine variants, including two recent circulating Delta isolates. RESULTS: The results show high inter-individual heterogeneity in nAbs, especially according to the variant tested. The major variations among nAbs are based on the genotype responsible for the infection. Patients previously infected with the beta and B.1.160 variants had the lowest nAb titres. We show that this heterogeneity is well explained by spike protein mutants modelling using in silico approaches. The highest titres were observed in individuals vaccinated with the Pfizer/BioNTech COVID-19 vaccine, even against the delta variant. CONCLUSIONS: Immunity acquired naturally after infection is highly dependent on the infecting variant, and, unexpectedly, mRNA-based vaccine efficacy was shown to be often better than natural immunity in eliciting neutralising antibodies.

9.
Preprint in English | EuropePMC | ID: ppcovidwho-291158

ABSTRACT

Purpose: Several brain complications of SARS-CoV-2 infection have been reported. It has been moreover speculated that this neurotropism could potentially cause a delayed outbreak of neuropsychiatric and neurodegenerative diseases of neuroinflammatory origin. A propagation mechanism has been proposed across the cribriform plate of the ethmoid bone, from the nose to the olfactory epithelium, and possibly afterwards to other limbic structures, and deeper parts of the brain including the brainstem. Methods: : Review of clinical examination, and whole-brain voxel-based analysis of 18 F-FDG PET metabolism in comparison to healthy subjects (p-voxel<0.001, p-cluster<0.05), of two patients with confirmed diagnosis of SARS-CoV-2 pneumonia explored at the post-viral stage of the disease. Results: : Hypometabolism of the olfactory/rectus gyrus was found on the two patients, especially one with 4 weeks prolonged anosmia. Additional hypometabolisms were found within bilateral amygdala, hippocampus, cingulate cortex, thalamus, pons and medulla brainstem in the other patient who complained of delayed onset of an atypical painful syndrome. Conclusion: These preliminary findings reinforce the hypotheses of SARS-CoV-2 neurotropism through the olfactory bulb, and the possible extension of this impairment to other limbic structures and to the brainstem. 18 F-FDG PET hypometabolism could constitute a cerebral quantitative biomarker of this involvement. Post-viral cohort studies are required to specify the exact relationship between limbic/brainstem hypometabolisms and the possible persistent disorders, especially involving cognitive or emotion disturbances, residual respiratory symptoms or painful complaints.

10.
Front Microbiol ; 12: 675528, 2021.
Article in English | MEDLINE | ID: covidwho-1456295

ABSTRACT

The rapid spread of SARS-CoV-2 variants has quickly spanned doubts and the fear about their ability escape vaccine protection. Some of these variants initially identified in caged were also found in humans. The claim that these variants exhibited lower susceptibility to antibody neutralization led to the slaughter of 17 million minks in Denmark. SARS-CoV-2 prevalence tests led to the discovery of infected farmed minks worldwide. In this study, we revisit the issue of the circulation of SARS-CoV-2 variants in minks as a model of sarbecovirus interspecies evolution by: (1) comparing human and mink angiotensin I converting enzyme 2 (ACE2) and neuropilin 1 (NRP-1) receptors; (2) comparing SARS-CoV-2 sequences from humans and minks; (3) analyzing the impact of mutations on the 3D structure of the spike protein; and (4) predicting linear epitope targets for immune response. Mink-selected SARS-CoV-2 variants carrying the Y453F/D614G mutations display an increased affinity for human ACE2 and can escape neutralization by one monoclonal antibody. However, they are unlikely to lose most of the major epitopes predicted to be targets for neutralizing antibodies. We discuss the consequences of these results for the rational use of SARS-CoV-2 vaccines.

12.
13.
Rev Cardiovasc Med ; 22(3): 1063-1072, 2021 09 24.
Article in English | MEDLINE | ID: covidwho-1439023

ABSTRACT

We evaluated the age-specific mortality of unselected adult outpatients infected with SARS-CoV-2 treated early in a dedicated COVID-19 day hospital and we assessed whether the use of hydroxychloroquine (HCQ) + azithromycin (AZ) was associated with improved survival in this cohort. A retrospective monocentric cohort study was conducted in the day hospital of our center from March to December 2020 in adults with PCR-proven infection who were treated as outpatients with a standardized protocol. The primary endpoint was 6-week mortality, and secondary endpoints were transfer to the intensive care unit and hospitalization rate. Among 10,429 patients (median age, 45 [IQR 32-57] years; 5597 [53.7%] women), 16 died (0.15%). The infection fatality rate was 0.06% among the 8315 patients treated with HCQ+AZ. No deaths occurred among the 8414 patients younger than 60 years. Older age and male sex were associated with a higher risk of death, ICU transfer, and hospitalization. Treatment with HCQ+AZ (0.17 [0.06-0.48]) was associated with a lower risk of death, independently of age, sex and epidemic period. Meta-analysis evidenced consistency with 4 previous outpatient studies (32,124 patients-Odds ratio 0.31 [0.20-0.47], I2 = 0%). Early ambulatory treatment of COVID-19 with HCQ+AZ as a standard of care is associated with very low mortality, and HCQ+AZ improve COVID-19 survival compared to other regimens.


Subject(s)
Ambulatory Care , Antiviral Agents/therapeutic use , Azithromycin/therapeutic use , COVID-19/drug therapy , Early Medical Intervention , Hydroxychloroquine/therapeutic use , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Antiviral Agents/adverse effects , Azithromycin/adverse effects , COVID-19/diagnosis , COVID-19/mortality , Drug Therapy, Combination , Female , France , Hospitalization , Humans , Hydroxychloroquine/adverse effects , Male , Middle Aged , Outpatients , Retrospective Studies , Risk Assessment , Risk Factors , Sex Factors , Time Factors , Treatment Outcome , Young Adult
14.
Front Med (Lausanne) ; 8: 663708, 2021.
Article in English | MEDLINE | ID: covidwho-1435999

ABSTRACT

Coronavirus disease 2019 (COVID-19) is now at the forefront of major health challenge faced globally, creating an urgent need for safe and efficient therapeutic strategies. Given the high attrition rates, high costs, and quite slow development of drug discovery, repurposing of known FDA-approved molecules is increasingly becoming an attractive issue in order to quickly find molecules capable of preventing and/or curing COVID-19 patients. Cyclosporin A (CsA), a common anti-rejection drug widely used in transplantation, has recently been shown to exhibit substantial anti-SARS-CoV-2 antiviral activity and anti-COVID-19 effect. Here, we review the molecular mechanisms of action of CsA in order to highlight why this molecule seems to be an interesting candidate for the therapeutic management of COVID-19 patients. We conclude that CsA could have at least three major targets in COVID-19 patients: (i) an anti-inflammatory effect reducing the production of proinflammatory cytokines, (ii) an antiviral effect preventing the formation of the viral RNA synthesis complex, and (iii) an effect on tissue damage and thrombosis by acting against the deleterious action of angiotensin II. Several preliminary CsA clinical trials performed on COVID-19 patients report lower incidence of death and suggest that this strategy should be investigated further in order to assess in which context the benefit/risk ratio of repurposing CsA as first-line therapy in COVID-19 is the most favorable.

15.
Infect Genet Evol ; 95: 105092, 2021 11.
Article in English | MEDLINE | ID: covidwho-1433676

ABSTRACT

OBJECTIVES: To compare the demographics, clinical characteristics and severity of patients infected with nine different SARS-CoV-2 variants, during three phases of the COVID-19 epidemic in Marseille. METHODS: A single centre retrospective cohort study was conducted in 1760 patients infected with SARS-CoV-2 of Nextstrain clades 20A, 20B, and 20C (first phase, February-May 2020), Pangolin lineages B.1.177 (we named Marseille-2) and B.1.160 (Marseille-4) variants (second phase, June-December 2020), and B.1.1.7 (alpha), B.1.351 (beta), P.1 (gamma) and A.27 (Marseille-501) variants (third phase, January 2021-today). Outcomes were the occurrence of clinical failures, including hospitalisation, transfer to the intensive-care unit, and death. RESULTS: During each phase, no major differences were observed with regards to age and gender distribution, the prevalence of chronic diseases, and clinical symptoms between variants circulating in a given phase. The B.1.177 and B.1.160 variants were associated with more severe outcomes. Infections occurring during the second phase were associated with a higher rate of death as compared to infections during the first and third phases. Patients in the second phase were more likely to be hospitalised than those in the third phase. Patients infected during the third phase were more frequently obese than others. CONCLUSION: A large cohort study is recommended to evaluate the transmissibility and to better characterise the clinical severity of emerging variants.


Subject(s)
COVID-19/pathology , Diabetes Mellitus/pathology , Genome, Viral , Hypertension/pathology , Obesity/pathology , SARS-CoV-2/pathogenicity , Adult , Aged , COVID-19/epidemiology , COVID-19/mortality , COVID-19/virology , Comorbidity , Diabetes Mellitus/epidemiology , Diabetes Mellitus/mortality , Diabetes Mellitus/virology , Female , France/epidemiology , Genotype , Heart Diseases/epidemiology , Heart Diseases/mortality , Heart Diseases/pathology , Heart Diseases/virology , Hospitalization/statistics & numerical data , Hospitals , Humans , Hypertension/epidemiology , Hypertension/mortality , Hypertension/virology , Intensive Care Units , Male , Middle Aged , Neoplasms/epidemiology , Neoplasms/mortality , Neoplasms/pathology , Neoplasms/virology , Obesity/epidemiology , Obesity/mortality , Obesity/virology , Phylogeny , Retrospective Studies , SARS-CoV-2/classification , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Sequence Analysis, RNA , Severity of Illness Index , Survival Analysis
16.
Front Med (Lausanne) ; 8: 737602, 2021.
Article in English | MEDLINE | ID: covidwho-1430710

ABSTRACT

Since the start of COVID-19 pandemic the Republic of Djibouti, in the horn of Africa, has experienced two epidemic waves of the virus between April and August 2020 and between February and May 2021. By May 2021, COVID-19 had affected 1.18% of the Djiboutian population and caused 152 deaths. Djibouti hosts several foreign military bases which makes it a potential hot-spot for the introduction of different SARS-CoV-2 strains. We genotyped fifty three viruses that have spread during the two epidemic waves. Next, using spike sequencing of twenty-eight strains and whole genome sequencing of thirteen strains, we found that Nexstrain clades 20A and 20B with a typically European D614G substitution in the spike and a frequent P2633L substitution in nsp16 were the dominant viruses during the first epidemic wave, while the clade 20H South African variants spread during the second wave characterized by an increase in the number of severe forms of COVID-19.

17.
J Clin Med ; 10(13)2021 Jun 30.
Article in English | MEDLINE | ID: covidwho-1403797

ABSTRACT

(1) Background: We collected COVID-19 mortality data and the age distribution of the deceased in France and other European countries, as well as specifically in the cities of Paris and Marseille, and compared them. (2) Methods: Data on mortality related to COVID-19 and the associated age distribution were collected from government institutions in various European countries. In France, data were obtained from INSEE and Santé Publique France. All-cause mortality was also examined in order to study potential excess mortality using EuroMOMO. The Marseille data came from the epidemiological surveillance system. (3) Results: France is one of the European countries most impacted by COVID-19. Its proportion of deaths in people under 60 years of age is higher (6.5%) than that of Italy (4.6%) or Spain (4.7%). Excess mortality (5% more deaths) was also observed. Ile-de-France and the Grand-Est are the two French regions with the highest mortality. The proportion of deaths in the under-60 age group was considerable in Ile-de-France (9.9% vs. 4.5% in the Southern region). There are significantly higher numbers of patients hospitalized, in intensive care and deceased in Paris than in Marseille. (4) Conclusions: No patient management, i.e., from screening to diagnosis, including biological assessment and clinical examination, likely explains the high mortality associated with COVID-19.

18.
Travel Med Infect Dis ; 43: 102122, 2021.
Article in English | MEDLINE | ID: covidwho-1392589
19.
Viruses ; 13(5)2021 04 28.
Article in English | MEDLINE | ID: covidwho-1389539

ABSTRACT

It has now been over a year since SARS-CoV-2 first emerged in China, in December 2019, and it has spread rapidly around the world. Some variants are currently considered of great concern. We aimed to analyze the numbers of SARS-CoV-2 genome sequences obtained in different countries worldwide until January 2021. On 28 January 2021, we downloaded the deposited genome sequence origin from the GISAID database, and from the "Our world in data" website we downloaded numbers of SARS-CoV-2-diagnosed cases, numbers of SARS-CoV-2-associated deaths, population size, life expectancy, gross domestic product (GDP) per capita, and human development index per country. Files were merged and data were analyzed using Microsoft Excel software. A total of 450,968 SARS-CoV-2 genomes originating from 135 countries on the 5 continents were available. When considering the 19 countries for which the number of genomes per 100 deaths was >100, six were in Europe, while eight were in Asia, three were in Oceania and two were in Africa. Six (30%) of these countries are beyond rank 75, regarding the human development index and four (20%) are beyond rank 80 regarding GDP per capita. Moreover, the comparisons of the number of genomes sequenced per 100 deaths to the human development index by country show that some Western European countries have released similar or lower numbers of genomes than many African or Asian countries with a lower human development index. Previous data highlight great discrepancies between the numbers of available SARS-CoV-2 genomes per 100 cases and deaths and the ranking of countries regarding wealth and development.


Subject(s)
COVID-19/virology , Genome, Viral , SARS-CoV-2/genetics , Africa/epidemiology , Asia/epidemiology , COVID-19/epidemiology , Databases, Genetic , Europe/epidemiology , Global Health , High-Throughput Nucleotide Sequencing , Humans , Pandemics
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