Modeling SARS-CoV-2 viral kinetics and association with mortality in hospitalized patients from the French COVID cohort.

The characterization of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral kinetics in hospitalized patients and its association with mortality is unknown. We analyzed death and nasopharyngeal viral kinetics in 655 hospitalized patients from the prospective French COVID cohort. The model predicted a median peak viral load that coincided with symptom onset. Patients with age ≥65 y had a smaller loss rate of infected cells, leading to a delayed median time to viral clearance occurring 16 d after symptom onset as compared to 13 d in younger patients (P < 10-4). In multivariate analysis, the risk factors associated with mortality were age ≥65 y, male gender, and presence of chronic pulmonary disease (hazard ratio [HR] > 2.0). Using a joint model, viral dynamics after hospital admission was an independent predictor of mortality (HR = 1.31, P < 10-3). Finally, we used our model to simulate the effects of effective pharmacological interventions on time to viral clearance and mortality. A treatment able to reduce viral production by 90% upon hospital admission would shorten the time to viral clearance by 2.0 and 2.9 d in patients of age <65 y and ≥65 y, respectively. Assuming that the association between viral dynamics and mortality would remain similar to that observed in our population, this could translate into a reduction of mortality from 19 to 14% in patients of age ≥65 y with risk factors. Our results show that viral dynamics is associated with mortality in hospitalized patients. Strategies aiming to reduce viral load could have an effect on mortality rate in this population.

The endocytic recycling compartment serves as a viral factory for hepatitis E virus.

Although hepatitis E virus (HEV) is the major leading cause of enterically transmitted viral hepatitis worldwide, many gaps remain in the understanding of the HEV lifecycle. Notably, viral factories induced by HEV have not been documented yet, and it is currently unknown whether HEV infection leads to cellular membrane modeling as many positive-strand RNA viruses. HEV genome encodes the ORF1 replicase, the ORF2 capsid protein and the ORF3 protein involved in virion egress. Previously, we demonstrated that HEV produces different ORF2 isoforms including the virion-associated ORF2i form. Here, we generated monoclonal antibodies that specifically recognize the ORF2i form and antibodies that recognize the different ORF2 isoforms. One antibody, named P1H1 and targeting the ORF2i N-terminus, recognized delipidated HEV particles from cell culture and patient sera. Importantly, AlphaFold2 modeling demonstrated that the P1H1 epitope is exposed on HEV particles. Next, antibodies were used to probe viral factories in HEV-producing/infected cells. By confocal microscopy, we identified subcellular nugget-like structures enriched in ORF1, ORF2 and ORF3 proteins and viral RNA. Electron microscopy analyses revealed an unprecedented HEV-induced membrane network containing tubular and vesicular structures. We showed that these structures are dependent on ORF2i capsid protein assembly and ORF3 expression. An extensive colocalization study of viral proteins with subcellular markers, and silencing experiments demonstrated that these structures are derived from the endocytic recycling compartment (ERC) for which Rab11 is a central player. Hence, HEV hijacks the ERC and forms a membrane network of vesicular and tubular structures that might be the hallmark of HEV infection.

A morphometric analysis of hepatitis B subviral particles shows no correlation of filament proportion and length with clinical stage and genotype.

It was recently suggested that the composition of circulating hepatitis B subviral particles (SVPs) could be used to differentiate the various stages in chronic hepatitis B virus (HBV) infection, with significantly lower proportions of L and M proteins in inactive carriers than in individuals with chronic hepatitis. L protein is abundant in virions and filamentous SVPs but almost absent from spherical SVPs. We, therefore, performed a morphometric analysis of SVPs in these two groups of patients, by conducting a retrospective analysis on sera from 15 inactive carriers and 11 patients with chronic hepatitis infected with various HBV genotypes. Subviral particles were concentrated by centrifugation on a sucrose cushion, with monitoring by transmission electron microscopy. The percentage of filamentous SVPs and filament length for 100 SVPs was determined with a digital camera. The L protein PreS1 promoter was sequenced from viral genomes by the Sanger method. No marked differences were found between patients, some of whom had only spherical SVPs, whereas others had variable percentages of filamentous SVPs (up to 28%), of highly variable length. High filament percentages were not associated with a particular sequence of the L protein promoter, HBV genotype or even disease stage. High levels of circulating filamentous SVPs are probably more strongly related to individual host factors than to viral strain characteristics or disease stage.

Rapid SARS-CoV-2 inactivation by mercury and LED UV-C lamps on different surfaces.

SARS-CoV-2 remains infectious for several hours on surfaces. It can be inactivated by UV-C irradiation but optimal conditions for rapid inactivation, especially on non-plastic surfaces remains unclear. A SARS-CoV-2 inoculum was irradiated with a UV-C LED (265 nm) or a UV-C mercury lamp (254 nm). Infectivity titers (TCID50/mL) and inactivation rates were then quantified on plastic, steel, tissue, paper and cardboard surfaces. We demonstrated that efficient SARS-CoV-2 inactivation (> 99.999% on plastic and steel, ≥ 99.8% on tissue, paper and cardboard) can be achieved by both a UV-C mercury lamp and a UV-C LED after 30 s of irradiations at 3 cm, corresponding to UV-C doses of 92.85 and 44.7 mJ/cm2, respectively. Inactivation on a plastic surface was more efficient with the mercury UV-C lamp (p < 0.005). The mercury UV-C lamp could be more relevant than the LED in high-risk settings, such as medical care or research laboratories.

Treatment of chronic hepatitis B: virological and pharmacological aspects / Traitement de l'hépatite B chronique par ténofovir : aspects virologiques et pharmacologiques

Tenofovir is a nucleotidic analog inhibitor used in monotherapy as first line treatment of chronic Hepatitis B virus (HBV) infection. This drug requires a two-step phosphorylation by cellular kinases. The active triphosphate form inhibits viral DNA polymerase. Tenofovir has a very low oral bioavailability following oral administration. Hence, its oral administration requires the use of prodrugs: tenofovir disoproxil fumararate (TDF) or tenofovir alafénamide (TAF). TAF demonstrated a lower kidney and bone toxicity than TDF. TAF and TDF treatments allow prevention of chronic hepatitis B complications, which are cirrhosis and hepatocellular carcinoma. Prevention of these complications requires a virological response to the treatment, defined as undetectable HBV DNA. TDF and TAF are associated with virological response rates from 64 to 94 % after one year of treatment. This rate depends on HBV viral load at diagnostic, HBe antigen status, mutations in the HBV polymerase gene (Pol/RT) and patient compliance to the treatment. Tenofovir has a high genetic barrier and resistance mutations to this drug have not yet been described. However, mutations rt181T/V and/or rtN236T have been associated with reduced susceptibility to TDF/TAF in vitro and delayed response in vivo. Recently described mutations CYEI and rtA194T have been associated with reduced susceptibility to TDF/TAF in vitro without any change in viral response in vivo. Patient compliance can be improved using cognitive behavioral therapy, supporter interventions and use of short message service. Finally, some genetic polymorphisms in MRP(multidrug resistance-associated protein)-2 and MRP4 efflux transporters could be associated with TDF toxicity and virological response to TDF or TAF. In the perspective of functional HBV cure, TDF and TAF are likely to be still used, in association with new class of antivirals. For this reason, it is important to further characterize the pharmacological and virological factors associated with partial virological response to tenofovir.

Le ténofovir est un analogue nucléotidique inhibiteur de l'ADN polymérase à activité de transcriptase inverse du virus de l'hépatite B (VHB). Il nécessite une métabolisation intra-cellulaire par des kinases cellulaires pour obtenir la forme triphosphate active. Cette dernière est incorporée à l'ADN viral en cours de synthèse et exerce un effet terminateur de chaîne. Le ténofovir est administré sous forme de promédicaments : le ténofovir disoproxil fumarate (TDF) ou le ténofovir alafénamide (TAF). Le TAF se caractérise par une meilleure tolérance rénale et osseuse que le TDF. Le TDF et le TAF sont indiqués en monothérapie de longue durée pour le traitement de première intention des hépatites B chroniques. Ce traitement permet de prévenir la cirrhose et le carcinome hépatocellulaire qui sont les principales complications de l'hépatite B chronique. Le critère principal de suivi est l'obtention d'une réponse virologique, définie par une charge virale VHB indétectable. Le TDF et le TAF sont associés à des taux de réponse virologique de 64 à 94 % après un an de traitement. Ce taux de réponse dépend de facteurs virologiques, notamment le statut antigène HBe, la charge virale VHB au diagnostic et la présence de certaines mutations dans la polymérase virale (Pol/RT). Aucune résistance au ténofovir n'a été décrite au cours des essais cliniques, ce qui reflète la barrière génétique élevée associée à cette molécule. Néanmoins, les mutations rt181T/V et/ou rtN236T peuvent réduire la sensibilité au ténofovir in vitro et retarder la réponse virologique in vivo. Les mutations CYEI et A194T, récemment décrites, diminuent aussi la sensibilité au ténofovir in vitro mais ne semblent pas avoir d'impact sur la réponse au traitement. La réponse virologique dépend aussi de facteurs de l'hôte, principalement l'observance au traitement, cruciale pour prévenir les complications de l'infection. Cette observance peut être améliorée par des approches comportementales, le soutien d'un tiers ou des rappels par message texte. Enfin, certains polymorphismes génétiques au niveau des transporteurs MRP (multidrug resistance-associated protein)-2 ou MRP4 pourraient moduler la réponse virologique et la tolérance rénale du ténofovir. Dans une perspective de guérison fonctionnelle de l'hépatite chronique B, le ténofovir sera très probablement toujours utilisé, en association avec de nouveaux antiviraux. Pour ces raisons, il semble important de poursuivre l'identification des facteurs pharmacologiques et virologiques associés à la réponse virologique au ténofovir.

Two-step strategy for the identification of SARS-CoV-2 variant of concern 202012/01 and other variants with spike deletion H69-V70, France, August to December 2020.

We report the strategy leading to the first detection of variant of concern 202012/01 (VOC) in France (21 December 2020). First, the spike (S) deletion H69-V70 (ΔH69/ΔV70), identified in certain SARS-CoV-2 variants including VOC, is screened for. This deletion is associated with a S-gene target failure (SGTF) in the three-target RT-PCR assay (TaqPath kit). Subsequently, SGTF samples are whole genome sequenced. This approach revealed mutations co-occurring with ΔH69/ΔV70 including S:N501Y in the VOC.

Synthesis and Antiviral Evaluation of (1,4-Disubstituted-1,2,3-Triazol)-(E)-2-Methyl-but-2-Enyl Nucleoside Phosphonate Prodrugs.

A series of hitherto unknown (1,4-disubstituted-1,2,3-triazol)-(E)-2-methyl-but-2-enyl nucleosides phosphonate prodrugs bearing 4-substituted-1,2,3-triazoles were prepared in a straight approach through an olefin acyclic cross metathesis as the key synthetic step. All novel compounds were evaluated for their antiviral activities against HBV, HIV and SARS-CoV-2. Among these molecules, only compound 15j, a hexadecyloxypropyl (HDP)/(isopropyloxycarbonyl-oxymethyl)-ester (POC) prodrug, showed activity against HBV in Huh7 cell cultures with 62% inhibition at 10 µM, without significant cytotoxicity (IC50 = 66.4 µM in HepG2 cells, IC50 = 43.1 µM in HepG2 cells) at 10 µM.

Fatal Measles Inclusion-Body Encephalitis in Adult with Untreated AIDS, France.

We report a fatal case of measles inclusion-body encephalitis occurring in a woman from Romania with AIDS. After an extensive but unsuccessful diagnostic evaluation, a pan-pathogen shotgun metagenomic approach revealed a measles virus infection. We identified no mutations previously associated with neurovirulence.

Genetic Diversity within Alphaherpesviruses: Characterization of a Novel Variant of Herpes Simplex Virus 2.

UNLABELLED: Very low levels of variability have been reported for the herpes simplex virus 2 (HSV-2) genome. We recently described a new genetic variant of HSV-2 (HSV-2v) characterized by a much higher degree of variability for the UL30 gene (DNA polymerase) than observed for the HG52 reference strain. Retrospective screening of 505 clinical isolates of HSV-2 by a specific real-time PCR assay targeting the UL30 gene led to the identification of 13 additional HSV-2v isolates, resulting in an overall prevalence of 2.8%. Phylogenetic analyses on the basis of microsatellite markers and gene sequences showed clear differences between HSV-2v and classical HSV-2. Thirteen of the 14 patients infected with HSV-2v originated from West or Central Africa, and 9 of these patients were coinfected with HIV. These results raise questions about the origin of this new virus. Preliminary results suggest that HSV-2v may have acquired genomic segments from chimpanzee alphaherpesvirus (ChHV) by recombination. IMPORTANCE: This article deals with the highly topical question of the origin of this new HSV-2 variant identified in patients with HIV coinfection originating mostly from West or Central Africa. HSV-2v clearly differed from classical HSV-2 isolates in phylogenetic analyses and may be linked to simian ChHV. This new HSV-2 variant highlights the possible occurrence of recombination between human and simian herpesviruses under natural conditions, potentially presenting greater challenges for the future.

Comparison of LUMIPULSE(®) G1200 With Kryptor and Modular E170 for the Measurement of Seven Tumor Markers.

BACKGROUND: Tumor marker measurements are becoming essential for prognosis and follow-up of patients in oncology. In this context, we aimed to compare a new analyzer, Lumipulse(®) G1200 (Fujirebio group, distributed in Europe by the Innogenetics group) with Kryptor(®) (Thermo Fisher Scientific B.R.A.H.M.S, Asnières, France) and Modular(®) Elecsys E170 (Roche Diagnostics, Meylan, France) for the measurement of seven tumor markers: PSA, AFP, CEA, CA 15-3, CA 125, CA 19-9, and Cyfra 21-1. METHODS: A total of 471 serum samples from patients with elevated tumor markers and 100 serum from healthy patients were analyzed with Lumipulse(®) G1200 and either Kryptor(®) (for AFP) or Modular(®) (for the six other markers). RESULTS: The good precision of Lumipulse(®) G1200 assays was confirmed with CVs < 2.5% and < 5.0%, obtained, respectively, for within-run imprecision and intermediate imprecision (except for Cyfra 21-1: CV < 13%). For all markers, Lumipulse results were well correlated with Modular or Kryptor results (r ≥ 0.94). Concordance of results interpretation was > 95% and tumor marker kinetics were all similar. CONCLUSION: We confirmed the analytical performances of Lumipulse(®) tumor marker assays except for the CYFRA 21-1 assay for which performances were poor in this study. We noticed a few discrepancies for the CEA assay. Besides, values obtained for CA 19-9 were higher with Lumipulse leading to a bias (slope = 1.5). But for the four other tumor markers assays (PSA, AFP, CA 125, CA 15-3), the results were directly transferable between Lumipulse and Kryptor or Modular, thus facilitating an eventual substitution of one system by another.

Relevance of Tacrolimus Trough Concentration and Hepatitis E virus Genetic Changes in Kidney Transplant Recipients With Chronic Hepatitis E.

Introduction: Hepatitis E virus (HEV) can cause chronic infection (≥3 months) and cirrhosis in immunocompromised patients, especially kidney transplant recipients. Low alanine aminotransferase (ALT) levels and high HEV intrahost diversity have previously been associated with evolution toward chronicity in these patients. We hypothesized that additional clinical and viral factors could be associated with the risk of chronic HEV infection. Methods: We investigated a series of 27 kidney transplant recipients with HEV infection, including 20 patients with chronic hepatitis E. Results: High tacrolimus trough concentration at diagnosis was the most relevant marker associated with chronic hepatitis E (9.2 vs. 6.4 ng/ml, P = 0.04). Most HEV genetic changes selected during HEV infection were compartmentalized between plasma and feces. Conclusion: This compartmentalization highlights the diversity and complexity of HEV replication compartments. Tacrolimus trough concentration at diagnosis of HEV infection could allow an early identification of patients at high risk of chronic hepatitis E and guide treatment initiation.

Impact of influenza immunity on the mortality among older adults hospitalized with COVID-19: a retrospective cohort study.

It has been suggested that the outcomes of coronavirus disease 2019 (COVID-19) are better in individuals having recently received an influenza vaccine than in non-vaccinated individuals. We hypothesized that this association depends on the humoral responses against influenza viruses. We aim to assess the relationship between the humoral immunity against influenza and the 3-month all-cause mortality among hospitalized older patients with COVID-19. We performed an exploratory retrospective study of older patients (aged 65 and over) hospitalized for confirmed COVID-19 between November 2020 and June 2021. Previous humoral responses to influenza viruses were assessed using a hemagglutination inhibition assay on routinely collected blood samples. The study's primary outcome was the 3-month all-cause mortality, and the secondary outcomes were severe COVID-19 (oxygen requirement ≥ 6 L/min or ventilatory support) and complications (kidney or heart failure, thrombosis and bacterial infection). In the cohort of 95 patients with COVID-19, immunity against influenza vaccine subtypes/lineages was not significantly associated with 3-month all-cause mortality, with an OR [95%CI] of 0.22 [0.02-1.95] (p = 0.174) for the H1N1pdm09 subtype, 0.21 [0.03-1.24] (p = 0.081) for A/Hong Kong/2671/2019 H3N2 subtype, 1.98 [0.51-8.24] (p = 0.329) for the B/Victoria lineage, and 1.82 [0.40-8.45] (p = 0.437) for the B/Yamagata lineage. Immunity against influenza vaccine subtypes/lineages was also not significantly associated with severity and complication. Immunity against influenza subtypes/lineages included in the 2020-2021 vaccine was not associated with a lower 3-month all-cause mortality among COVID-19 hospitalized patients.Trial registration: The study was approved by a hospital committee with competency for research not requiring approval by an institutional review board (Tours University Medical Center, Tours, France: reference: 2021_015). All patients give the informed consent.

A pig model of chronic hepatitis E displaying persistent viremia and a downregulation of innate immune responses in the liver.

BACKGROUND: Hepatitis E virus (HEV) is a zoonotic virus transmitted by pig meat and responsible for chronic hepatitis E in immunocompromised patients. It has proved challenging to reproduce this disease in its natural reservoir. We therefore aimed to develop a pig model of chronic hepatitis E to improve the characterization of this disease. METHODS: Ten pigs were treated with a tacrolimus-based regimen and intravenously inoculated with HEV. Tacrolimus trough concentration, HEV viremia, viral diversity, innate immune responses, liver histology, clinical disease and biochemical markers were monitored for 11 weeks post-infection (p.i.). RESULTS: HEV viremia persisted for 11 weeks p.i. HEV RNA was detected in the liver, small intestine, and colon at necropsy. Histological analysis revealed liver inflammation and fibrosis. Several mutations selected in the HEV genome were associated with compartmentalization in the feces and intestinal tissues, consistent with the hypothesis of extrahepatic replication in the digestive tract. Antiviral responses were characterized by a downregulation of IFN pathways in the liver, despite an upregulation of RIG-I and ISGs in the blood and liver. CONCLUSIONS: We developed a pig model of chronic hepatitis E that reproduced the major hallmarks of this disease. This model revealed a compartmentalization of HEV genomes in the digestive tract and a downregulation of innate immune responses in the liver. These original features highlight the relevance of our model for studies of the pathogenesis of chronic hepatitis E and for validating future treatments.

ELISA-Based Analysis Reveals an Anti-SARS-CoV-2 Protein Immune Response Profile Associated with Disease Severity.

Since the start of the COVID-19 pandemic, many studies have investigated the humoral response to SARS-CoV-2 during infection. Studies with native viral proteins constitute a first-line approach to assessing the overall immune response, but small peptides are an accurate and valuable tool for the fine characterization of B-cell epitopes, despite the restriction of this approach to the determination of linear epitopes. In this study, we used ELISA and peptides covering a selection of structural and non-structural SARS-CoV-2 proteins to identify key epitopes eliciting a strong immune response that could serve as a biological signature of disease characteristics, such as severity, in particular. We used 213 plasma samples from a cohort of patients well-characterized clinically and biologically and followed for COVID-19 infection. We found that patients developing severe disease had higher titers of antibodies mapping to multiple specific epitopes than patients with mild to moderate disease. These data are potentially important as they could be used for immunological profiling to improve our knowledge of the quantitative and qualitative characteristics of the humoral response in relation to patient outcome.

Specific changes of erythroid regulators and hepcidin in patients infected by SARS-COV-2.

Iron metabolism is tightly linked to infectious and inflammatory signals through hepcidin synthesis. To date, iron homeostasis during SARS-CoV-2 infection has not yet been described. The aim of this study is to characterize the hepcidin and erythroid regulators (growth differentiation factor 15 (GDF-15) and erythroferrone (ERFE)) by measuring concentrations in plasma in context of COVID-19 disease.We performed a single-center observational study of patients with COVID-19 to evaluate concentrations of main regulatory proteins involved in iron homeostasis, namely: hepcidin, ERFE and GDF-15. SARS-CoV-2 infection (COVID-19+) was defined by a positive RT-PCR. Sixteen patients with COVID-19+ were gender-matched and age-matched to 16 patients with a sepsis unrelated to SARS-CoV-2 (COVID-19-) and were compared with non-parametric statistic test.Clinical and hematological parameters, plasma iron, transferrin, transferrin saturation, ferritin, soluble transferrin receptor and C reactive protein were not statistically different between both groups. Median plasma hepcidin concentrations were higher in the COVID-19+ group (44.1 (IQR 16.55-70.48) vs 14.2 (IQR 5.95-18.98) nmol/L, p=0.003), while median ERFE and GDF-15 concentrations were lower in the COVID-19+ group (0.16 (IQR 0.01-0.73) vs 0.89 (IQR 0.19-3.82) ng/mL, p=0.035; 2003 (IQR 1355-2447) vs 4713 (IQR 2082-7774) pg/mL, p=0015), respectively) compared with the COVID-19- group.This is the first study reporting lower ERFE and GDF-15 median concentrations in patients with COVID-19+ compared with patients with COVID-19-, associated with an increased median concentration of hepcidin in the COVID-19+ group compared with COVID19- group.

Antibody Responses after a Third Dose of COVID-19 Vaccine in Kidney Transplant Recipients and Patients Treated for Chronic Lymphocytic Leukemia.

The impact of a third dose of COVID-19 vaccine on antibody responses is unclear in immunocompromised patients. The objective of this retrospective study was to characterize antibody responses induced by a third dose of mRNA COVID-19 vaccine in 160 kidney transplant recipients and 20 patients treated for chronic lymphocytic leukemia (CLL). Prevalence of anti-spike IgG ≥ 7.1 and ≥ 30 BAU/mL after the third dose were 47% (75/160) and 39% (63/160) in kidney transplant recipients, and 57% (29/51) and 50% (10/20) in patients treated for CLL. Longitudinal follow-up identified a moderate increase in SARS-CoV-2 anti-spike IgG levels after a third dose of vaccine in kidney transplant recipients (0.19 vs. 5.28 BAU/mL, p = 0.03) and in patients treated for CLL (0.63 vs. 10.7 BAU/mL, p = 0.0002). This increase in IgG levels had a limited impact on prevalence of anti-spike IgG ≥ 30 BAU/mL in kidney transplant recipients (17%, 2/12 vs. 33%, 4/12, p = 0.64) and in patients treated for CLL (5%, 1/20 vs. 45%, 9/20, p = 0.008). These results highlight the need for vaccination of the general population and the importance of non-medical preventive measures to protect immunocompromised patients.

Evolution and phenotypic characterization of whole HBV genome in compliant patients experiencing unexplained entecavir treatment failure.

Entecavir treatment failure can be observed in compliant patients despite an absence of detectable resistance mutations by Pol/RT Sanger sequencing. We hypothesized that these unexplained treatment failures could rely on other mechanisms of viral resistance, especially on mutations selected outside of the Pol/RT domain. Partial virological response to entecavir was observed in three patients treated with immunosuppressive drugs, without selection of Pol/RT resistance mutations. Mutations selected in the whole HBV genome during entecavir treatment and potentially associated with resistance were searched for using deep sequencing and characterized using a phenotypic resistance assay. Mutations Q206K (pre-core/core), Q120K (pre-S1/pre-S2, T-cell epitope) and A300E (spacer domain) were selected during entecavir treatment in patient #1 but were not associated with an increased level of resistance to entecavir or an increase in HBV replication capacity. Core promoter mutations T1753G, A1762T and G1764A were present as major mutations before and after treatment in patient #1. HBs Ag immune escape mutations were present as major mutations before and after treatment in patients #2 (sK122R, sT126I, sP127S and sG145R) and #3 (sM133I). We demonstrated that PVR to entecavir does not require selection of any resistance mutation in the whole HBV genome. Our results demonstrate that major mutations can be selected outside of the Pol/RT domain before or during entecavir treatment. These mutations could contribute to entecavir treatment failure by other mechanisms than an increased level of resistance.

Humoral immunity to SARS-CoV-2 and seasonal coronaviruses in children and adults in north-eastern France.

BACKGROUND: Children are underrepresented in the COVID-19 pandemic and often experience milder disease than adolescents and adults. Reduced severity is possibly due to recent and more frequent seasonal human coronaviruses (HCoV) infections. We assessed the seroprevalence of SARS-CoV-2 and seasonal HCoV specific antibodies in a large cohort in north-eastern France. METHODS: In this cross-sectional seroprevalence study, serum samples were collected from children and adults requiring hospital admission for non-COVID-19 between February and August 2020. Antibody responses to SARS-CoV-2 and seasonal HCoV (229E, HKU1, NL63, OC43) were assessed using a bead-based multiplex assay, Luciferase-Linked ImmunoSorbent Assay, and a pseudotype neutralisation assay. FINDINGS: In 2,408 individuals, seroprevalence of SARS-CoV-2-specific antibodies was 7-8% with three different immunoassays. Antibody levels to seasonal HCoV increased substantially up to the age of 10. Antibody responses in SARS-CoV-2 seropositive individuals were lowest in adults 18-30 years. In SARS-CoV-2 seronegative individuals, we observed cross-reactivity between antibodies to the four HCoV and SARS-CoV-2 Spike. In contrast to other antibodies to SARS-CoV-2, specific antibodies to sub-unit 2 of Spike (S2) in seronegative samples were highest in children. Upon infection with SARS-CoV-2, antibody levels to Spike of betacoronavirus OC43 increased across the whole age spectrum. No SARS-CoV-2 seropositive individuals with low levels of antibodies to seasonal HCoV were observed. INTERPRETATION: Our findings underline significant cross-reactivity between antibodies to SARS-CoV-2 and seasonal HCoV, but provide no significant evidence for cross-protective immunity to SARS-CoV-2 infection due to a recent seasonal HCoV infection. In particular, across all age groups we did not observe SARS-CoV-2 infected individuals with low levels of antibodies to seasonal HCoV. FUNDING: This work was supported by the « URGENCE COVID-19 ¼ fundraising campaign of Institut Pasteur, by the French Government's Investissement d'Avenir program, Laboratoire d'Excellence Integrative Biology of Emerging Infectious Diseases (Grant No. ANR-10-LABX-62-IBEID), and by the REACTing (Research & Action Emerging Infectious Diseases), and by the RECOVER project funded by the European Union's Horizon 2020 research and innovation programme under grant agreement No. 101003589, and by a grant from LabEx IBEID (ANR-10-LABX-62-IBEID).

Influenza vaccination as a novel means of preventing coronary heart disease: Effectiveness in older adults.

Atherosclerosis can have various etiologies, including several newly recognized immunoinflammatory mechanisms. A growing body of evidence suggests that influenza infection is chronologically linked to acute myocardial infarction (AMI), and thus that the virus is a novel cardiovascular disease (CVD) risk factor. Morbidity and mortality rates for both influenza infection and AMI rise markedly with age. Epidemiological studies have demonstrated that influenza vaccination (IV) has a cardioprotective effect, especially in people aged 65 and over; hence, IV may be of value in the management of CVD. These observations justify efforts to better understand the underlying mechanisms and to identify therapeutic targets in older adults. In view of the above, the objective of the present study was to review the literature data on the cellular mechanisms that link IV to the prevention of atherosclerotic complications. Given the greater burden of CVD in older subjects, we also questioned the impact of aging on this association. The most widely recognized benefit of IV is the prevention of influenza infection and the latter's cardiovascular complications. In a new hypothesis, however, an influenza-independent effect is driven by vaccine immunity and modulation of the ongoing immunoinflammatory response in individuals with CVD. Although influenza infection and IV both induce a proinflammatory response, they have opposite effects on the progression of atherosclerosis - suggesting a hormetic phenomenon. Aging is characterized by chronic inflammation (sometimes referred to as "inflammaging") that progresses insidiously during the course of aging-related diseases, including CVD. It remains to be determined whether vaccination has an effect on aging-related diseases other than CVD. Although the studies of this topic had various limitations, the results highlight the potential benefits of vaccination in protecting the health of older adults, and should drive research on the molecular immunology of the response to IV and its correlation with atheroprotective processes.

Clinical performance of four immunoassays for antibodies to SARS-CoV-2, including a prospective analysis for the diagnosis of COVID-19 in a real-life routine care setting.

OBJECTIVES: The aim of the present study was to evaluate the clinical performance of four SARS-CoV-2 immunoassays and their contribution in routine care for the diagnosis of COVID-19, in order to benefit of robust data before their extensive use. METHODS: The clinical performance of Euroimmun ELISA SARS-CoV-2 IgG, Abbott SARS-CoV-2 IgG, Wantai SARS-CoV-2 Ab ELISA, and DiaPro COVID-19 IgG confirmation were evaluated in the context of both a retrospective and a prospective analysis of COVID-19 patients. The retrospective analysis included plasma samples from 63 COVID-19 patients and 89 control (pre-pandemic) patients. The prospective study included 203 patients who tested either negative (n = 181) or positive (n = 22) by RT-PCR before serology sampling. RESULTS: The specificity was 92.1 %, 98.9 %, 100 % and 98.9 % and the sensitivity 14 days after onset of symptoms was 95.6 %, 95.6 %, 97.8 % and 95.6 % for Euroimmun IgG, Abbott IgG, Wantai Ab, and DiaPro IgG confirmation SARS-CoV-2 immunoassays, respectively. The low specificity of Euroimmun IgG (for ratio <5) was not confirmed in routine care setting (98.5 % negative agreement). Serology was complementary to RT-PCR in routine care and lead to identification of false positive (Ct>38, <2 targets detected) and false negative RT-PCR results (>1 month post onset of symptoms). CONCLUSIONS: Serology was complementary to RT-PCR for the diagnosis of COVID-19 at least 14 days after onset of symptoms. First line serology testing can be performed with Wantai Ab or Abbott IgG assays, while DiaPro IgG confirmation assay can be used as an efficient confirmation assay.