Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 8.822
Filter
1.
Nat Commun ; 14(1): 3334, 2023 06 07.
Article in English | MEDLINE | ID: covidwho-20241659

ABSTRACT

COVID-19 patients at risk of severe disease may be treated with neutralising monoclonal antibodies (mAbs). To minimise virus escape from neutralisation these are administered as combinations e.g. casirivimab+imdevimab or, for antibodies targeting relatively conserved regions, individually e.g. sotrovimab. Unprecedented genomic surveillance of SARS-CoV-2 in the UK has enabled a genome-first approach to detect emerging drug resistance in Delta and Omicron cases treated with casirivimab+imdevimab and sotrovimab respectively. Mutations occur within the antibody epitopes and for casirivimab+imdevimab multiple mutations are present on contiguous raw reads, simultaneously affecting both components. Using surface plasmon resonance and pseudoviral neutralisation assays we demonstrate these mutations reduce or completely abrogate antibody affinity and neutralising activity, suggesting they are driven by immune evasion. In addition, we show that some mutations also reduce the neutralising activity of vaccine-induced serum.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , Antibodies, Monoclonal/therapeutic use , Immunotherapy , Mutation , Antibodies, Neutralizing , Antibodies, Viral
2.
J Immunol ; 211(2): 252-260, 2023 07 15.
Article in English | MEDLINE | ID: covidwho-20241408

ABSTRACT

SARS-CoV-2 has caused an estimated 7 million deaths worldwide to date. A secreted SARS-CoV-2 accessory protein, known as open reading frame 8 (ORF8), elicits inflammatory pulmonary cytokine responses and is associated with disease severity in COVID-19 patients. Recent reports proposed that ORF8 mediates downstream signals in macrophages and monocytes through the IL-17 receptor complex (IL-17RA, IL-17RC). However, generally IL-17 signals are found to be restricted to the nonhematopoietic compartment, thought to be due to rate-limiting expression of IL-17RC. Accordingly, we revisited the capacity of IL-17 and ORF8 to induce cytokine gene expression in mouse and human macrophages and monocytes. In SARS-CoV-2-infected human and mouse lungs, IL17RC mRNA was undetectable in monocyte/macrophage populations. In cultured mouse and human monocytes and macrophages, ORF8 but not IL-17 led to elevated expression of target cytokines. ORF8-induced signaling was fully preserved in the presence of anti-IL-17RA/RC neutralizing Abs and in Il17ra-/- cells. ORF8 signaling was also operative in Il1r1-/- bone marrow-derived macrophages. However, the TLR/IL-1R family adaptor MyD88, which is dispensable for IL-17R signaling, was required for ORF8 activity yet MyD88 is not required for IL-17 signaling. Thus, we conclude that ORF8 transduces inflammatory signaling in monocytes and macrophages via MyD88 independently of the IL-17R.


Subject(s)
COVID-19 , Monocytes , Humans , Mice , Animals , Monocytes/metabolism , SARS-CoV-2/genetics , Myeloid Differentiation Factor 88/genetics , Myeloid Differentiation Factor 88/metabolism , Receptors, Interleukin-17/genetics , Receptors, Interleukin-17/metabolism , Open Reading Frames , COVID-19/genetics , Macrophages/metabolism , Cytokines/metabolism
3.
Euro Surveill ; 28(22)2023 Jun.
Article in English | MEDLINE | ID: covidwho-20241314

ABSTRACT

BackgroundSuccessive epidemic waves of COVID-19 illustrated the potential of SARS-CoV-2 variants to reshape the pandemic. Detecting and characterising emerging variants is essential to evaluate their public health impact and guide implementation of adapted control measures.AimTo describe the detection of emerging variant, B.1.640, in France through genomic surveillance and present investigations performed to inform public health decisions.MethodsIdentification and monitoring of SARS-CoV-2 variant B.1.640 was achieved through the French genomic surveillance system, producing 1,009 sequences. Additional investigation of 272 B.1.640-infected cases was performed between October 2021 and January 2022 using a standardised questionnaire and comparing with Omicron variant-infected cases.ResultsB.1.640 was identified in early October 2021 in a school cluster in Bretagne, later spreading throughout France. B.1.640 was detected at low levels at the end of SARS-CoV-2 Delta variant's dominance and progressively disappeared after the emergence of the Omicron (BA.1) variant. A high proportion of investigated B.1.640 cases were children aged under 14 (14%) and people over 60 (27%) years, because of large clusters in these age groups. B.1.640 cases reported previous SARS-CoV-2 infection (4%), anosmia (32%) and ageusia (34%), consistent with data on pre-Omicron SARS-CoV-2 variants. Eight percent of investigated B.1.640 cases were hospitalised, with an overrepresentation of individuals aged over 60 years and with risk factors.ConclusionEven though B.1.640 did not outcompete the Delta variant, its importation and continuous low-level spread raised concerns regarding its public health impact. The investigations informed public health decisions during the time that B.1.640 was circulating.


Subject(s)
COVID-19 , SARS-CoV-2 , Child , Humans , Middle Aged , Aged , SARS-CoV-2/genetics , COVID-19/epidemiology , France/epidemiology , Pandemics
4.
BMJ Open Ophthalmol ; 7(Suppl 2): A3, 2022 11.
Article in English | MEDLINE | ID: covidwho-20241143

ABSTRACT

INTRODUCTION/BACKGROUND: At the beginning of the COVID-19 pandemic, eye banks around the world had to assess the impact of SARS-CoV-2 infection in potential ocular tissue donors and decide how to characterise donors to meet ongoing demand for tissue for transplantation.NHSBT eye banks normally issue cornea grafts for over 4000 transplants per annum (pre-pandemic). SARS-CoV2 RNA screening is not a requirement for eye donor characterisation. Donor authorisation is based on review of donor medical and contact history and any available COVID test results (e.g. from hospital testing or as part of organ donor characterisation). After retrieval, globes are disinfected with PVP-iodine, and corneas stored in organ culture.This presentation explores the impact of COVID-19 on corneal donation and transplantation in England. METHODS: UK Transplant Registry data were analysed on all corneal donors and transplants in England from 1 January 2020 to 2 July 2021. All laboratory confirmed SARS CoV-2 infections were collected by Public Health England from 16 March 2020. Information was available until mid-November 2021.To assess the possibility of transmission through a transplanted graft, cases with a diagnosis of infection within 14 days post transplant were identified for further review. RESULTS: 4130 corneal grafts were performed in England. We are aware of 222 recipients who tested positive for SARS-CoV2. 2 of these have been reported to have died within 28 days of testing positive. The diagnosis of SARS-CoV2 infection in these 2 recipients had been made beyond 30 days post transplant.In 3 of the 222 infected recipients, the interval between transplant and infection was within 14 days (all 3 recipients alive). 2 of the 3 donors were fully characterised organ donors (universally screened for SARS-CoV-2 RNA in upper and lower respiratory tract samples), and one was an eye only donor who had tested negative in hospital 2 days prior to death. CONCLUSIONS: The linkage of large registries allows collection of useful data in a large cohort of patients transplanted during the COVID-19 pandemic. The incidence of COVID-19 and characteristics of corneal transplant recipients who tested positive for SARS-CoV2 were found to be similar to those for the general population of England.These data have not identified any epidemiological evidence for transmission of COVID-19 through corneal transplantation, and offer reassurance about the safety and quality systems that are in place to allow ongoing corneal transplantation during the pandemic.


Subject(s)
COVID-19 , Corneal Transplantation , Humans , COVID-19/diagnosis , RNA, Viral , SARS-CoV-2/genetics , Pandemics , England/epidemiology
5.
Front Immunol ; 14: 1130539, 2023.
Article in English | MEDLINE | ID: covidwho-20241121

ABSTRACT

The highly transmissible Omicron (B.1.1.529) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first detected in late 2021. Initial Omicron waves were primarily made up of sub-lineages BA.1 and/or BA.2, BA.4, and BA.5 subsequently became dominant in mid-2022, and several descendants of these sub-lineages have since emerged. Omicron infections have generally caused less severe disease on average than those caused by earlier variants of concern in healthy adult populations, at least, in part, due to increased population immunity. Nevertheless, healthcare systems in many countries, particularly those with low population immunity, have been overwhelmed by unprecedented surges in disease prevalence during Omicron waves. Pediatric admissions were also higher during Omicron waves compared with waves of previous variants of concern. All Omicron sub-lineages exhibit partial escape from wild-type (Wuhan-Hu 1) spike-based vaccine-elicited neutralizing antibodies, with sub-lineages with more enhanced immuno-evasive properties emerging over time. Evaluating vaccine effectiveness (VE) against Omicron sub-lineages has become challenging against a complex background of varying vaccine coverage, vaccine platforms, prior infection rates, and hybrid immunity. Original messenger RNA vaccine booster doses substantially improved VE against BA.1 or BA.2 symptomatic disease. However, protection against symptomatic disease waned, with reductions detected from 2 months after booster administration. While original vaccine-elicited CD8+ and CD4+ T-cell responses cross-recognize Omicron sub-lineages, thereby retaining protection against severe outcomes, variant-adapted vaccines are required to expand the breadth of B-cell responses and improve durability of protection. Variant-adapted vaccines were rolled out in late 2022 to increase overall protection against symptomatic and severe infections caused by Omicron sub-lineages and antigenically aligned variants with enhanced immune escape mechanisms.


Subject(s)
COVID-19 , Vaccines , Adult , Humans , Child , COVID-19/epidemiology , COVID-19/prevention & control , SARS-CoV-2/genetics , Vaccine Efficacy , Cost of Illness
6.
Viruses ; 15(5)2023 04 24.
Article in English | MEDLINE | ID: covidwho-20241085

ABSTRACT

Qualitative SARS-CoV-2 antigen assays based on immunochromatography are useful for mass diagnosis of COVID-19, even though their sensitivity is poor in comparison with RT-PCR assays. In addition, quantitative assays could improve antigenic test performance and allow testing with different specimens. Using quantitative assays, we tested 26 patients for viral RNA and N-antigen in respiratory samples, plasma and urine. This allowed us to compare the kinetics between the three compartments and to compare RNA and antigen concentrations in each. Our results showed the presence of N-antigen in respiratory (15/15, 100%), plasma (26/59, 44%) and urine (14/54, 28.9%) samples, whereas RNA was only detected in respiratory (15/15, 100%) and plasma (12/60, 20%) samples. We detected N-antigen in urine and plasma samples until the day 9 and day 13 post-inclusion, respectively. The antigen concentration was found to correlate with RNA levels in respiratory (p < 0.001) and plasma samples (p < 0.001). Finally, urinary antigen levels correlated with plasma levels (p < 0.001). Urine N-antigen detection could be part of the strategy for the late diagnosis and prognostic evaluation of COVID-19, given the ease and painlessness of sampling and the duration of antigen excretion in this biological compartment.


Subject(s)
Blood Group Antigens , COVID-19 , Humans , SARS-CoV-2/genetics , COVID-19/diagnosis , Kinetics , Respiratory System , RNA, Viral/genetics , Sensitivity and Specificity
7.
Nat Commun ; 14(1): 3105, 2023 05 29.
Article in English | MEDLINE | ID: covidwho-20241073

ABSTRACT

Epidemiological models are commonly fit to case and pathogen sequence data to estimate parameters and to infer unobserved disease dynamics. Here, we present an inference approach based on sequence data that is well suited for model fitting early on during the expansion of a viral lineage. Our approach relies on a trajectory of segregating sites to infer epidemiological parameters within a Sequential Monte Carlo framework. Using simulated data, we first show that our approach accurately recovers key epidemiological quantities under a single-introduction scenario. We then apply our approach to SARS-CoV-2 sequence data from France, estimating a basic reproduction number of approximately 2.3-2.7 under an epidemiological model that allows for multiple introductions. Our approach presented here indicates that inference approaches that rely on simple population genetic summary statistics can be informative of epidemiological parameters and can be used for reconstructing infectious disease dynamics during the early expansion of a viral lineage.


Subject(s)
COVID-19 , Communicable Diseases , Viruses , Humans , COVID-19/epidemiology , SARS-CoV-2/genetics , Viruses/genetics , Basic Reproduction Number , Bayes Theorem
8.
Antimicrob Agents Chemother ; 67(7): e0026623, 2023 07 18.
Article in English | MEDLINE | ID: covidwho-20240989

ABSTRACT

The emergence of the Omicron variant of SARS-CoV-2 represented a challenge to the treatment of COVID-19 using monoclonal antibodies. Only Sotrovimab maintained partial activity, allowing it to be used in high-risk patients infected with the Omicron variant. However, reports of resistance mutations to Sotrovimab demand efforts to better understand the intra-patient emergence of Sotrovimab resistance. A retrospective genomic analysis was conducted on respiratory samples from immunocompromised patients infected with SARS-CoV-2 who received Sotrovimab at our hospital between December 2021 and August 2022. The study involved 95 sequential specimens from 22 patients (1 to 12 samples/patient; 3 to 107 days post-infusion; threshold cycle [CT] ≤ 32). Resistance mutations (in P337, E340, K356, and R346) were detected in 68% of cases; the shortest time to detection of a resistance mutation was 5 days after Sotrovimab infusion. The dynamics of resistance acquisition were highly complex, with up to 11 distinct amino acid changes in specimens from the same patient. In two patients, the mutation distribution was compartmentalized in respiratory samples from different sources. This is the first study to examine the acquisition of Sotrovimab resistance in the BA.5 lineage, enabling us to determine the lack of genomic or clinical differences between Sotrovimab resistance in BA.5 relative to that in BA.1/2. Across all Omicron lineages, the acquisition of resistance delayed SARS-CoV-2 clearance (40.67 versus 19.5 days). Close, real-time genomic surveillance of patients receiving Sotrovimab should be mandatory to facilitate early therapeutic interventions.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , Retrospective Studies , Genomics , Mutation , Antibodies, Neutralizing
9.
Vopr Virusol ; 67(6): 496-505, 2023 02 07.
Article in Russian | MEDLINE | ID: covidwho-20240924

ABSTRACT

INTRODUCTION: SARS-CoV-2, a severe acute respiratory illness virus that emerged in China in late 2019, continues to spread rapidly around the world, accumulating mutations and thus causing serious concern. Five virus variants of concern are currently known: Alpha (lineage B.1.1.7), Beta (lineage B.1.351), Gamma (lineage P.1), Delta (lineage B.1.617.2), and Omicron (lineage B.1.1.529). In this study, we conducted a molecular epidemiological analysis of the most prevalent genovariants in Moscow and the region. The aim of the study is to estimate the distribution of various variants of SARS-CoV-2 in Moscow city and the Moscow Region. MATERIALS AND METHODS: 227 SARS-CoV-2 sequences were used for analysis. Isolation of the SARS-CoV-2 virus was performed on Vero E6 cell culture. Sequencing was performed by the Sanger method. Bioinformatic analysis was carried out using software packages: MAFFT, IQ-TREE v1.6.12, jModelTest 2.1.7, Nextstrain, Auspice v2.34. RESULTS: As a result of phylogenetic analysis, we have identified the main variants of the virus circulating in Russia that have been of concern throughout the existence of the pandemic, namely: variant B.1.1.7, which accounted for 30% (9/30), AY.122, which accounted for 16.7% (5/30), BA.1.1 with 20% (6/30) and B.1.1 with 33.3% (10/30). When examining Moscow samples for the presence of mutations in SARS-CoV-2 structural proteins of different genovariants, a significant percentage of the most common substitutions was recorded: S protein D614G (86.7%), P681H/R (63.3%), E protein T9I (20.0%); M protein I82T (30.0%), D3G (20.0%), Q19E (20.0%) and finally N protein R203K/M (90.0%), G204R/P (73.3 %). CONCLUSION: The study of the frequency and impact of mutations, as well as the analysis of the predominant variants of the virus are important for the development and improvement of vaccines for the prevention of COVID-19. Therefore, ongoing molecular epidemiological studies are needed, as these data provide important information about changes in the genome of circulating SARS-CoV-2 variants.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , Moscow/epidemiology , COVID-19/epidemiology , Phylogeny
10.
J Med Virol ; 95(6): e28847, 2023 06.
Article in English | MEDLINE | ID: covidwho-20240737

ABSTRACT

Recently emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variants are generally less pathogenic than previous strains. However, elucidating the molecular basis for pulmonary immune response alterations is challenging owing to the virus's heterogeneous distribution within complex tissue structure. Here, we revealed the spatial transcriptomic profiles of pulmonary microstructures at the SARS-CoV-2 infection site in the nine cynomolgus macaques upon inoculation with the Delta and Omicron variants. Delta- and Omicron-infected lungs had upregulation of genes involved in inflammation, cytokine response, complement, cell damage, proliferation, and differentiation pathways. Depending on the tissue microstructures (alveoli, bronchioles, and blood vessels), there were differences in the types of significantly upregulated genes in each pathway. Notably, a limited number of genes involved in cytokine and cell damage response were differentially expressed between bronchioles of the Delta- and Omicron-infection groups. These results indicated that despite a significant antigenic shift in SARS-CoV-2, the host immune response mechanisms induced by the variants were relatively consistent, with limited transcriptional alterations observed only in large airways. This study may aid in understanding the pathogenesis of SARS-CoV-2 and developing a clinical strategy for addressing immune dysregulation by identifying potential transcriptional biomarkers within pulmonary microstructures during infection with emerging variants.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , SARS-CoV-2/genetics , Transcriptome , COVID-19/genetics , Pulmonary Alveoli , Cytokines/genetics , Macaca
11.
J Infect Public Health ; 16(8): 1290-1300, 2023 Aug.
Article in English | MEDLINE | ID: covidwho-20240577

ABSTRACT

BACKGROUND: Modern response to pandemics, critical for effective public health measures, is shaped by the availability and integration of diverse epidemiological outbreak data. Tracking variants of concern (VOC) is integral to understanding the evolution of SARS-CoV-2 in space and time, both at the local level and global context. This potentially generates actionable information when integrated with epidemiological outbreak data. METHODS: A city-wide network of researchers, clinicians, and pathology diagnostic laboratories was formed for genome surveillance of COVID-19 in Pune, India. The genomic landscapes of 10,496 sequenced samples of SARS-CoV-2 driving peaks of infection in Pune between December-2020 to March-2022, were determined. As a modern response to the pandemic, a "band of five" outbreak data analytics approach was used. This integrated the genomic data (Band 1) of the virus through molecular phylogenetics with key outbreak data including sample collection dates and case numbers (Band 2), demographics like age and gender (Band 3-4), and geospatial mapping (Band 5). RESULTS: The transmission dynamics of VOCs in 10,496 sequenced samples identified B.1.617.2 (Delta) and BA(x) (Omicron formerly known as B.1.1.529) variants as drivers of the second and third peaks of infection in Pune. Spike Protein mutational profiling during pre and post-Omicron VOCs indicated differential rank ordering of high-frequency mutations in specific domains that increased the charge and binding properties of the protein. Time-resolved phylogenetic analysis of Omicron sub-lineages identified a highly divergent BA.1 from Pune in addition to recombinant X lineages, XZ, XQ, and XM. CONCLUSIONS: The band of five outbreak data analytics approach, which integrates five different types of data, highlights the importance of a strong surveillance system with high-quality meta-data for understanding the spatiotemporal evolution of the SARS-CoV-2 genome in Pune. These findings have important implications for pandemic preparedness and could be critical tools for understanding and responding to future outbreaks.


Subject(s)
COVID-19 , Pandemics , Humans , COVID-19/epidemiology , SARS-CoV-2/genetics , Phylogeny , India/epidemiology , Genomics
12.
BMC Genomics ; 24(1): 312, 2023 Jun 10.
Article in English | MEDLINE | ID: covidwho-20240423

ABSTRACT

BACKGROUND: The emergence and rapid spread of new severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) variants have challenged the control of the COVID-19 pandemic globally. Burundi was not spared by that pandemic, but the genetic diversity, evolution, and epidemiology of those variants in the country remained poorly understood. The present study sought to investigate the role of different SARS-COV-2 variants in the successive COVID-19 waves experienced in Burundi and the impact of their evolution on the course of that pandemic. We conducted a cross-sectional descriptive study using positive SARS-COV-2 samples for genomic sequencing. Subsequently, we performed statistical and bioinformatics analyses of the genome sequences in light of available metadata. RESULTS: In total, we documented 27 PANGO lineages of which BA.1, B.1.617.2, AY.46, AY.122, and BA.1.1, all VOCs, accounted for 83.15% of all the genomes isolated in Burundi from May 2021 to January 2022. Delta (B.1.617.2) and its descendants predominated the peak observed in July-October 2021. It replaced the previously predominant B.1.351 lineage. It was itself subsequently replaced by Omicron (B.1.1.529, BA.1, and BA.1.1). Furthermore, we identified amino acid mutations including E484K, D614G, and L452R known to increase infectivity and immune escape in the spike proteins of Delta and Omicron variants isolated in Burundi. The SARS-COV-2 genomes from imported and community-detected cases were genetically closely related. CONCLUSION: The global emergence of SARS-COV-2 VOCs and their subsequent introductions in Burundi was accompanied by new peaks (waves) of COVID-19. The relaxation of travel restrictions and the mutations occurring in the virus genome played an important role in the introduction and the spread of new SARS-COV-2 variants in the country. It is of utmost importance to strengthen the genomic surveillance of SARS-COV-2, enhance the protection by increasing the SARS-COV-2 vaccine coverage, and adjust the public health and social measures ahead of the emergence or introduction of new SARS-COV-2 VOCs in the country.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19 Vaccines , Cross-Sectional Studies , Pandemics , COVID-19/epidemiology , Genomics
13.
J Med Virol ; 95(6): e28831, 2023 06.
Article in English | MEDLINE | ID: covidwho-20239959

ABSTRACT

Despite the higher transmissibility of Omicron Variant of Concern (VOC), several reports have suggested lower risk for hospitalization and severe outcomes compared to previous variants of SARS-CoV-2. This study, enrolling all COVID-19 adults admitted to a reference hospital who underwent both the S-gene-target-failure test and VOC identification by Sanger sequencing, aimed to describe the evolving prevalence of Delta and Omicron variants and to compare the main in-hospital outcomes of severity, during a trimester (December 2021 to March 2022) of VOCs' cocirculation. Factors associated with clinical progression to noninvasive ventilation (NIV)/mechanical ventilation (MV)/death within 10 days and to MV/admission to intensive care unit (ICU)/death within 28 days, were investigated through multivariable logistic regressions. Overall, VOCs were: Delta n = 130/428, Omicron n = 298/428 (sublineages BA.1 n = 275 and BA.2 n = 23). Until mid-February, Delta predominance shifted to BA.1, which was gradually displaced by BA.2 until mid-March. Participants with Omicron VOC were more likely to be older, fully vaccinated, with multiple comorbidities and to have a shorter time from symptoms' onset, and less likely to have systemic symptoms and respiratory complications. Although the need of NIV within 10 days and MV within 28 days from hospitalization and the admission to ICU were less frequent for patients with Omicron compared to those with Delta infections, mortality was similar between the two VOCs. In the adjusted analysis, multiple comorbidities and a longer time from symptoms' onset predicted 10-day clinical progression, while complete vaccination halved the risk. Multimorbidity was the only risk factor associated with 28-day clinical progression. In our population, in the first trimester of 2022, Omicron rapidly displaced Delta in COVID-19 hospitalized adults. Clinical profile and presentation differed between the two VOCs and, although Omicron infections showed a less severe clinical picture, no substantial differences for clinical progression were found. This finding suggests that any hospitalization, especially in more vulnerable individuals, may be at risk for severe progression, which is more related to the underlying frailty of patients than to the intrinsic severity of the viral variant.


Subject(s)
COVID-19 , SARS-CoV-2 , Adult , Humans , SARS-CoV-2/genetics , COVID-19/epidemiology , Hospitals , Disease Progression
14.
Viruses ; 15(5)2023 05 04.
Article in English | MEDLINE | ID: covidwho-20239924

ABSTRACT

Since the end of 2020, multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) have emerged and spread worldwide. Tracking their evolution has been a challenge due to the huge number of positive samples and limited capacities of whole-genome sequencing. Two in-house variant-screening RT-PCR assays were successively designed in our laboratory in order to detect specific known mutations in the spike region and to rapidly detect successively emerging VOCs. The first one (RT-PCR#1) targeted the 69-70 deletion and the N501Y substitution simultaneously, whereas the second one (RT-PCR#2) targeted the E484K, E484Q, and L452R substitutions simultaneously. To evaluate the analytical performance of these two RT-PCRs, 90 negative and 30 positive thawed nasopharyngeal swabs were retrospectively analyzed, and no discordant results were observed. Concerning the sensitivity, for RT-PCR#1, serial dilutions of the WHO international standard SARS-CoV-2 RNA, corresponding to the genome of an Alpha variant, were all detected up to 500 IU/mL. For RT-PCR#2, dilutions of a sample harboring the E484K substitution and of a sample harboring the L452R and E484Q substitutions were all detected up to 1000 IU/mL and 2000 IU/mL, respectively. To evaluate the performance in a real-life hospital setting, 1308 and 915 profiles of mutations, obtained with RT-PCR#1 and RT-PCR#2, respectively, were prospectively compared to next-generation sequencing (NGS) data. The two RT-PCR assays showed an excellent concordance with the NGS data, with 99.8% for RT-PCR#1 and 99.2% for RT-PCR#2. Finally, for each mutation targeted, the clinical sensitivity, the clinical specificity and the positive and negative predictive values showed excellent clinical performance. Since the beginning of the SARS-CoV-2 pandemic, the emergence of variants-impacting the disease's severity and the efficacy of vaccines and therapies-has forced medical analysis laboratories to constantly adapt to the strong demand for screening them. Our data showed that in-house RT-PCRs are useful and adaptable tools for monitoring such rapid evolution and spread of SARS-CoV-2 VOCs.


Subject(s)
COVID-19 , Humans , COVID-19/diagnosis , RNA, Viral/genetics , Retrospective Studies , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2/genetics , Hospitals , Mutation , COVID-19 Testing
15.
J Med Virol ; 95(6): e28848, 2023 Jun.
Article in English | MEDLINE | ID: covidwho-20239679

ABSTRACT

During COVID-19 pandemic, consensus genomic sequences were used for rapidly monitor the spread of the virus worldwide. However, less attention was paid to intrahost genetic diversity. In fact, in the infected host, SARS-CoV-2 consists in an ensemble of replicating and closely related viral variants so-called quasispecies. Here we show that intrahost single nucleotide variants (iSNVs) represent a target for contact tracing analysis. Our data indicate that in the acute phase of infection, in highly likely transmission links, the number of viral particles transmitted from one host to another (bottleneck size) is large enough to propagate iSNVs among individuals. Furthermore, we demonstrate that, during SARS-CoV-2 outbreaks when the consensus sequences are identical, it is possible to reconstruct the transmission chains by genomic investigations of iSNVs. Specifically, we found that it is possible to identify transmission chains by limiting the analysis of iSNVs to only three well-conserved genes, namely nsp2, ORF3, and ORF7.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , Quasispecies , Pandemics , Genome, Viral
16.
Hum Genomics ; 17(1): 50, 2023 06 07.
Article in English | MEDLINE | ID: covidwho-20239372

ABSTRACT

BACKGROUND: The use of molecular biomarkers for COVID-19 remains unconclusive. The application of a molecular biomarker in combination with clinical ones that could help classifying aggressive patients in first steps of the disease could help clinician and sanitary system a better management of the disease. Here we characterize the role of ACE2, AR, MX1, ERG, ETV5 and TMPRSS2 for trying a better classification of COVID-19 through knowledge of the disease mechanisms. METHODS: A total of 329 blood samples were genotyped in ACE2, MX1 and TMPRSS2. RNA analyses were also performed from 258 available samples using quantitative polymerase chain reaction for genes: ERG, ETV5, AR, MX1, ACE2, and TMPRSS2. Moreover, in silico analysis variant effect predictor, ClinVar, IPA, DAVID, GTEx, STRING and miRDB database was also performed. Clinical and demographic data were recruited from all participants following WHO classification criteria. RESULTS: We confirm the use of ferritin (p < 0.001), D-dimer (p < 0.010), CRP (p < 0.001) and LDH (p < 0.001) as markers for distinguishing mild and severe cohorts. Expression studies showed that MX1 and AR are significantly higher expressed in mild vs severe patients (p < 0.05). ACE2 and TMPRSS2 are involved in the same molecular process of membrane fusion (p = 4.4 × 10-3), acting as proteases (p = 0.047). CONCLUSIONS: In addition to the key role of TMPSRSS2, we reported for the first time that higher expression levels of AR are related with a decreased risk of severe COVID-19 disease in females. Moreover, functional analysis demonstrates that ACE2, MX1 and TMPRSS2 are relevant markers in this disease.


Subject(s)
COVID-19 , Female , Humans , COVID-19/genetics , Angiotensin-Converting Enzyme 2/genetics , SARS-CoV-2/genetics , Genetic Markers , Databases, Factual , Serine Endopeptidases/genetics , Myxovirus Resistance Proteins
17.
Sci Rep ; 13(1): 8557, 2023 05 26.
Article in English | MEDLINE | ID: covidwho-20239361

ABSTRACT

Access to vaccines against SARS-CoV-2 virus was limited in poor countries during the COVID-19 pandemic. Therefore, a low-cost mRNA vaccine, PTX-COVID19-B, was produced and evaluated in a Phase 1 trial. PTX-COVID19-B encodes Spike protein D614G variant without the proline-proline (986-987) mutation present in other COVID-19 vaccines. The aim of the study was to evaluate safety, tolerability, and immunogenicity of PTX-COVID19-B vaccine in healthy seronegative adults 18-64 years old. The trial design was observer-blinded, randomized, placebo-controlled, and tested ascending doses of 16-µg, 40-µg, or 100-µg in a total of 60 subjects who received two intramuscular doses, 4 weeks apart. Participants were monitored for solicited and unsolicited adverse events after vaccination and were provided with a Diary Card and thermometer to report any reactogenicity during the trial. Blood samples were collected on baseline, days 8, 28, 42, 90, and 180 for serum analysis of total IgG anti-receptor binding domain (RBD)/Spike titers by ELISA, and neutralizing antibody titers by pseudovirus assay. Titers in BAU/mL were reported as geometric mean and 95% CI per cohort. After vaccination, few solicited adverse events were observed and were mild to moderate and self-resolved within 48 h. The most common solicited local and systemic adverse event was pain at the injection site, and headache, respectively. Seroconversion was observed in all vaccinated participants, who showed high antibody titers against RBD, Spike, and neutralizing activity against the Wuhan strain. Neutralizing antibody titers were also detected against Alpha, Beta, and Delta variants of concerns in a dose dependent manner. All tested doses of PTX-COVID19-B were safe, well-tolerated, and provided a strong immunogenicity response. The 40-µg dose showed fewer adverse reactions than the 100-µg dose, and therefore was selected for a Phase 2 trial, which is currently ongoing.Clinical Trial Registration number: NCT04765436 (21/02/2021). ( https://clinicaltrials.gov/ct2/show/NCT04765436 ).


Subject(s)
COVID-19 Vaccines , COVID-19 , Adult , Humans , Adolescent , Young Adult , Middle Aged , COVID-19 Vaccines/adverse effects , SARS-CoV-2/genetics , COVID-19/prevention & control , Pandemics/prevention & control , mRNA Vaccines , Antibodies, Neutralizing , Immunogenicity, Vaccine , Antibodies, Viral , Double-Blind Method
18.
Sci Rep ; 13(1): 8743, 2023 05 30.
Article in English | MEDLINE | ID: covidwho-20239097

ABSTRACT

Spike glycoprotein of SARS-CoV-2 variants plays a critical role in infection and transmission through its interaction with human angiotensin converting enzyme 2 (hACE2) receptors. Prior findings using molecular docking and biomolecular studies reported varied findings on the difference in the interactions among the spike variants with the hACE2 receptors. Hence, it is a prerequisite to understand these interactions in a more precise manner. To this end, firstly, we performed ELISA with trimeric spike glycoproteins of SARS-CoV-2 variants including Wuhan Hu-1(Wild), Delta, C.1.2 and Omicron. Further, to study the interactions in a more specific manner by mimicking the natural infection, we developed hACE2 receptors expressing HEK-293T cell line, evaluated their binding efficiencies and competitive binding of spike variants with D614G spike pseudotyped virus. In line with the existing findings, we observed that Omicron had higher binding efficiency compared to Delta in both ELISA and Cellular models. Intriguingly, we found that cellular models could differentiate the subtle differences between the closely related C.1.2 and Delta in their binding to hACE2 receptors. Our study using the cellular model provides a precise method to evaluate the binding interactions between spike sub-lineages to hACE2 receptors.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , Angiotensin-Converting Enzyme 2/genetics , Molecular Docking Simulation , Spike Glycoprotein, Coronavirus/genetics , Protein Binding
19.
Nan Fang Yi Ke Da Xue Xue Bao ; 43(4): 516-526, 2023 Apr 20.
Article in Chinese | MEDLINE | ID: covidwho-20239030

ABSTRACT

OBJECTIVE: To establish a rapid detection and genotyping method for SARS-CoV-2 Omicron BA.4/5 variants using CRISPPR-Cas12a gene editing technology. METHODS: We combined reverse transcription-polymerase chain reaction (RT-PCR) and CRISPR gene editing technology and designed a specific CRISPPR RNA (crRNA) with suboptimal protospacer adjacent motifs (PAM) for rapid detection and genotyping of SARS- CoV-2 Omicron BA.4/5 variants. The performance of this RT- PCR/ CRISPPR-Cas12a assay was evaluated using 43 clinical samples of patients infected by wild-type SARS-CoV-2 and the Alpha, Beta, Delta, Omicron BA. 1 and BA. 4/5 variants and 20 SARS- CoV- 2-negative clinical samples infected with 11 respiratory pathogens. With Sanger sequencing method as the gold standard, the specificity, sensitivity, concordance (Kappa) and area under the ROC curve (AUC) of RT-PCR/CRISPPR-Cas12a assay were calculated. RESULTS: This assay was capable of rapid and specific detection of SARS- CoV-2 Omicron BA.4/5 variant within 30 min with the lowest detection limit of 10 copies/µL, and no cross-reaction was observed in SARS-CoV-2-negative clinical samples infected with 11 common respiratory pathogens. The two Omicron BA.4/5 specific crRNAs (crRNA-1 and crRNA-2) allowed the assay to accurately distinguish Omicron BA.4/5 from BA.1 sublineage and other major SARS-CoV-2 variants of concern. For detection of SARS-CoV-2 Omicron BA.4/5 variants, the sensitivity of the established assay using crRNA-1 and crRNA-2 was 97.83% and 100% with specificity of 100% and AUC of 0.998 and 1.000, respectively, and their concordance rate with Sanger sequencing method was 92.83% and 96.41%, respectively. CONCLUSION: By combining RT-PCR and CRISPPR-Cas12a gene editing technology, we successfully developed a new method for rapid detection and identification of SARS-CoV-2 Omicron BA.4/5 variants with a high sensitivity, specificity and reproducibility, which allows rapid detection and genotyping of SARS- CoV-2 variants and monitoring of the emerging variants and their dissemination.


Subject(s)
COVID-19 , Humans , CRISPR-Cas Systems , Genotype , Reproducibility of Results , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2/genetics , RNA , COVID-19 Testing
20.
Hum Vaccin Immunother ; 19(1): 2212571, 2023 12 31.
Article in English | MEDLINE | ID: covidwho-20239029

ABSTRACT

Since March 2020, the pandemic caused by SARS-CoV-2 has affected nearly all aspects of daily life. In this study, we investigated the age-stratified prevalence and genotype distribution of human papillomavirus (HPV) among females in Shandong province (eastern China) and aimed to provide guidance on HPV-based cervical cancer screening and vaccination. The distribution of HPV genotypes was analyzed using PCR-Reverse Dot Hybridization. The overall infection rate of HPV was 16.4%, which was dominated by high-risk genotypes. The most prevalent genotype was HPV16 (2.9%), followed by HPV52 (2.3%), HPV53 (1.8%), HPV58 (1.5%), and HPV51 (1.3%). Among the positive cases with HPV infection, single-genotype infection was significantly higher than that of multi-genotype infection. In subgroup analyses by age (≤25, 26-35, 36-45, 46-55, >55), HPV16, 52, and 53 were consistently the three most common hrHPV genotypes in all age groups. The infection rate of multi-genotypes in the ≤25 and >55 age groups was significantly higher than that in other age groups. A bimodal distribution of HPV infection rate was observed in different age groups. Among lrHPV genotypes, HPV6, HPV11, and HPV81 were the three most common types in the ≤25 age group, while in other age groups, HPV81, HPV42, and HPV43 are the three most common lrHPV genotypes. This study provides basic information on the distribution and genotypes of HPV in the female population in eastern China, which could improve the application of HPV diagnostic probes and vaccines.


Subject(s)
COVID-19 , Papillomavirus Infections , Uterine Cervical Neoplasms , Humans , Female , Uterine Cervical Neoplasms/prevention & control , Papillomavirus Infections/prevention & control , Human Papillomavirus Viruses , Pandemics , Prevalence , Early Detection of Cancer , COVID-19/epidemiology , SARS-CoV-2/genetics , Genotype , Papillomaviridae/genetics , Human papillomavirus 16/genetics , China/epidemiology
SELECTION OF CITATIONS
SEARCH DETAIL