Viral load in respiratory syncytial virus infected premature newborns under prophylaxis with palivizumab

ABSTRACT Given the critical role of pattern recognition receptors (PRRs) in acid nucleic recognition in the initiation of innate immunity and the orchestration of adaptive immunity, the aim of this study was to determine whether any heterogeneity of PRR expression in the airway tracts of infants with respiratory syncytial virus (RSV) infection might explain the broad clinical spectrum of RSV-associated bronchiolitis in infants. For this purpose, the levels of melanoma differentiation-associated protein-5 (MDA-5), retinoic acid inducible gene-1 (RIG-1), and Toll-like receptor 3 (TLR-3), TLR-7, TLR-8, and TLR-9 mRNAs were evaluated, using TaqMan quantitative reverse transcription-PCR, in cells from nasopharyngeal washes collected from 157 infants suffering from acute bronchiolitis whether or not they were associated with respiratory viruses. High interindividual variability was observed in both virus-positive and -negative infants; however, the relative gene expression levels of MDA-5, RIG-1, TLR-7, and TLR-8 were significantly higher in the virus-infected group, whereas the expression levels of TLR-3 and TLR-9 were not significantly different. The differences in the gene expression of MDA-5, RIG-1, TLR-7, and TLR-8 were more evident in infants with RSV infection than in those with bocavirus or rhinovirus infection. In RSV-infected infants, PRR-mRNA levels also were analyzed in relation to interferon protein levels, viral load, clinical severity, days of hospitalization, age, and body weight. A significant positive correlation was observed only between RSV viral load and RIG-1 mRNA levels. These findings provide the first direct evidence that, in infants with respiratory virus-associated bronchiolitis, especially RSV, there are substantial changes in PRR gene expression; this likely is an important determinant of the clinical outcome of bronchiolitis.

Download Full-text

Viral Load Dynamics and Clinical Disease Severity in Infants With Respiratory Syncytial Virus Infection

The Journal of Infectious Diseases ◽

10.1093/infdis/jiy655 ◽

2018 ◽

Vol 219 (8) ◽

pp. 1207-1215 ◽

Cited By ~ 23

Author(s):

Cristina Garcia-Mauriño ◽

Melissa Moore-Clingenpeel ◽

Jessica Thomas ◽

Sara Mertz ◽

Daniel M Cohen ◽

...

Keyword(s):

Viral Load ◽

Respiratory Syncytial Virus ◽

Virus Infection ◽

Disease Severity ◽

Respiratory Syncytial Virus Infection ◽

Clinical Disease ◽

Syncytial Virus

Download Full-text

Progress toward a Respiratory Syncytial Virus Vaccine

Clinical and Vaccine Immunology ◽

10.1128/cvi.00037-16 ◽

2016 ◽

Vol 23 (3) ◽

pp. 186-188 ◽

Cited By ~ 48

Author(s):

Kathleen M. Neuzil

Keyword(s):

Viral Load ◽

Respiratory Syncytial Virus ◽

Virus Vaccine ◽

Effective Vaccine ◽

Vaccine Candidates ◽

Target Populations ◽

Link Type ◽

History Of ◽

Syncytial Virus ◽

Respiratory Syncytial Virus Vaccine

ABSTRACTIn accompanying papers (P. L. Acosta, M. T. Caballero, and F. P. Polack, Clin Vaccine Immunol 23:189–195, 2016,http://dx.doi.org/10.1128/CVI.00609-15; M. Vissers, I. M. L. Ahout, M. I. de Jonge, and G. Ferwerda, Clin Vaccine Immunol 23:243–245, 2016,http://dx.doi.org/10.1128/CVI.00590-15) in this issue ofClinical and Vaccine Immunology, the history of and immune mechanisms underlying vaccine-enhanced respiratory syncytial virus (RSV) disease and of investigations of mucosal antibodies and their association with viral load in RSV-infected children, respectively, are described. This commentary discusses RSV vaccine candidates, target populations, and the challenges associated with achieving a safe and effective vaccine.

Download Full-text

Protective Effect of Prophylactic Administration of High Dose Vitamin A in the Lung Histopathologic Damage, but not in the Lung Viral Load Associated to Experimental Respiratory Syncytial Virus Infection (RSV) in BALB/c mice† 826

Pediatric Research ◽

10.1203/00006450-199804001-00847 ◽

1998 ◽

Vol 43 ◽

pp. 143-143

Author(s):

Teresa M De Sierra ◽

Rocio Pena ◽

Alfredo Ulloa ◽

Georgina Toussaint ◽

Jorge L Rosado ◽

...

Keyword(s):

Viral Load ◽

Respiratory Syncytial Virus ◽

Virus Infection ◽

Vitamin A ◽

Protective Effect ◽

Respiratory Syncytial Virus Infection ◽

High Dose ◽

Prophylactic Administration ◽

Syncytial Virus ◽

High Dose Vitamin

Download Full-text

A Randomized, Placebo-Controlled, Respiratory Syncytial Virus Human Challenge Study of the Antiviral Efficacy, Safety, and Pharmacokinetics of RV521, an Inhibitor of the RSV-F Protein

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01884-19 ◽

2019 ◽

Vol 64 (2) ◽

Cited By ~ 9

Author(s):

John DeVincenzo ◽

Dereck Tait ◽

John Efthimiou ◽

Julie Mori ◽

Young-In Kim ◽

...

Keyword(s):

Viral Load ◽

Respiratory Syncytial Virus ◽

Adverse Events ◽

Disease Severity ◽

Controlled Trial ◽

Primary Analysis ◽

Double Blind ◽

Challenge Virus ◽

F Protein ◽

Syncytial Virus

ABSTRACT Effective treatments for respiratory syncytial virus (RSV) infection are lacking. Here, we report a human proof-of-concept study for RV521, a small-molecule antiviral inhibitor of the RSV-F protein. In this randomized, double-blind, placebo-controlled trial, healthy adults were challenged with RSV-A Memphis-37b. After infection was confirmed (or 5 days after challenge virus inoculation), subjects received RV521 (350 mg or 200 mg) or placebo orally every 12 h for 5 days. The primary endpoint was area under the curve (AUC) for viral load, as assessed by reverse transcriptase quantitative PCR (RT-qPCR) of nasal wash samples. The primary efficacy analysis set included subjects successfully infected with RSV who received ≥1 dose of study drug. A total of 66 subjects were enrolled (n = 22 per group); 53 were included in the primary analysis set (RV521 350 mg: n = 16; 200 mg: n = 18; placebo: n = 19). The mean AUC of RT-qPCR-assessed RSV viral load (log10 PFU equivalents [PFUe]/ml · h) was significantly lower with RV521 350 mg (185.26; standard error [SE], 31.17; P = 0.002) and 200 mg (224.35; SE, 37.60; P = 0.007) versus placebo (501.39; SE, 86.57). Disease severity improved with RV521 350 mg and 200 mg versus placebo (P = 0.002 and P = 0.009, respectively, for AUC total symptom score [score × hours]). Daily nasal mucus weight was significantly reduced (P = 0.010 and P = 0.038 for RV521 350 mg and 200 mg, respectively, versus placebo). All treatment-emergent adverse events were grade 1 or 2. No subjects discontinued due to adverse events. There was no evidence of clinically significant viral resistance, and only three variants were detected. RV521 effectively reduced RSV viral load and disease severity in humans and was well tolerated. (This study has been registered at ClinicalTrials.gov under registration no. NCT03258502.)

Download Full-text

667. Preclinical Pharmacokinetic and Pharmacodynamic Characterization of EDP-938, a Novel and Potent NonFusion Replication Inhibitor of Respiratory Syncytial Virus

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.735 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S305-S306

Author(s):

Li-Juan Jiang ◽

Lisha Xu ◽

Meng Huang ◽

Shucha Zhang ◽

Yang Li ◽

...

Keyword(s):

Viral Load ◽

Respiratory Syncytial Virus ◽

Post Infection ◽

Human Liver ◽

Liver Microsomes ◽

Monkey Model ◽

Green Monkey ◽

Rsv Infection ◽

Syncytial Virus

Abstract Background Respiratory syncytial virus (RSV) infection presents a significant health challenge in young children, elderly and immunocompromised patients. To date, there are no effective treatments available. EDP-938 was designed to meet this unmet medical need and is currently in Phase 2 clinical trials. Herein we report its preclinical pharmacokinetic (PK) and pharmacodynamic (PD) properties. Methods The pharmacokinetics of EDP-938 following single intravenous and oral doses were determined in mice, rats, dogs, and monkeys. In vitro cellular permeability and metabolic stability were assayed using Caco-2 cells and human liver microsomes, respectively. In vivo pharmacodynamic efficacy of EDP-938 was conducted in the African green monkey model, in which animals experimentally challenged with RSV were orally dosed twice daily with 100 mg/kg EDP-938 for 6 days starting 24 hours prior to infection. Results EDP-938 was well absorbed in the preclinical species with oral bioavailability values ranging from 27.1% in dogs, 35.4% in mice, 35.7% in rats, and 39.5% in monkeys, after a single oral dose when formulated in 0.5% methylcellulose. EDP-938 showed a moderate in vitro permeability of 3.6 x 10–6 cm/sec in Caco-2 cells. Based on the outcome of these absorption studies, EDP-938 was projected to have good oral absorption in humans. EDP-938 had low intrinsic clearance of 5 mL/minute/mg in human liver microsomes. Moreover, EDP-938 demonstrated potent antiviral efficacy in an African green monkey model of RSV infection. In untreated monkeys the RSV RNA viral load in the bronchoalveolar lavage fluid peaked at 106 copies/mL on day 5 post-infection, by comparison in animals treated with EDP-938 the viral load was below the limit of detection by day 3 post-infection. The PK/PD modeling suggested that plasma trough concentrations ≥10 × EC90 led to >4-log viral load reduction in EDP-938 treated monkeys. Conclusion The favorable preclinical PK and PD properties of EDP-938 support its further clinical development as a novel treatment for RSV infection. Disclosures All authors: No reported disclosures.

Download Full-text

High Resolution Analysis of Respiratory Syncytial Virus Infection In Vivo

Viruses ◽

10.3390/v11100926 ◽

2019 ◽

Vol 11 (10) ◽

pp. 926 ◽

Cited By ~ 4

Author(s):

Waleed Aljabr ◽

Stuart Armstrong ◽

Natasha Y. Rickett ◽

Georgios Pollakis ◽

Olivier Touzelet ◽

...

Keyword(s):

Viral Load ◽

Respiratory Syncytial Virus ◽

The Elderly ◽

High Viral Load ◽

Label Free ◽

Respiratory Problems ◽

Viral Loads ◽

High Resolution Analysis ◽

Syncytial Virus

Human respiratory syncytial virus (HRSV) is a major cause of pediatric infection and also causes disease in the elderly and those with underlying respiratory problems. There is no vaccine for HRSV and anti-viral therapeutics are not broadly applicable. To investigate the effect of HRSV biology in children, nasopharyngeal aspirates were taken from children with different viral loads and a combined high throughput RNAseq and label free quantitative proteomics approach was used to characterize the nucleic acid and proteins in these samples. HRSV proteins were identified in the nasopharyngeal aspirates from infected children, and their abundance correlated with viral load (Ct value), confirming HRSV infection. Analysis of the HRSV genome indicated that the children were infected with sub-group A virus and that minor variants in nucleotide frequency occurred in discrete clusters along the HRSV genome, and within a patient clustered distinctly within the glycoprotein gene. Data from the samples were binned into four groups; no-HRSV infection (control), high viral load (Ct < 20), medium viral load (Ct = 20–25), and low viral load (Ct > 25). Cellular proteins associated with the anti-viral response (e.g., ISG15) were identified in the nasopharyngeal aspirates and their abundance was correlated with viral load. These combined approaches have not been used before to study HRSV biology in vivo and can be readily applied to the study the variation of virus host interactions.

Download Full-text

A41 Deep sequencing of respiratory syncytial virus links viral diversity to disease severity

Virus Evolution ◽

10.1093/ve/vez002.040 ◽

2019 ◽

Vol 5 (Supplement_1) ◽

Author(s):

Inne Nauwelaers ◽

Tiina Talts ◽

Monica Galiano ◽

Peter Openshaw

Keyword(s):

Viral Load ◽

Respiratory Syncytial Virus ◽

Disease Severity ◽

Illumina Sequencing ◽

Likelihood Method ◽

Evolutionary Analysis ◽

Viral Loads ◽

Ct Value ◽

A Genome ◽

Syncytial Virus

Abstract Respiratory syncytial virus (RSV) is a common virus that can cause bronchiolitis in infants and pneumonia in immunocompromised and elderly people. RSV belongs to the Pneumoviridae family and consists of a genome of 15 kb. Its genome contains ten genes that code for eleven proteins, with M2 coding for two different proteins in overlapping open reading frames. It is unclear why some infected children have severe disease and others have mild or asymptomatic disease. In this project, methods for complete genome sequencing of RSV via Sanger and Illumina MiSeq platforms were optimized. One hundred and twenty-four community samples (59 RSV A and 65 RSV B) from 2014 to 2018 were collected (in collaboration with the Royal College of General Practitioners) and sequenced. Samples were selected based on viral load (e.g. Ct values had to be < 30). The genotype of each sample was determined by constructing phylogenetic trees with reference sequences from all genotypes. Trees were reconstructed using the maximum likelihood method. Furthermore, Illumina sequencing was used to deep sequence seven community samples and four hospital samples that were spatiotemporally matched (obtained via Imperial College NHS Trust hospitals). Variants were studied to investigate if certain variants influence disease severity (e.g. cause mild (community samples) or severe infection (hospital samples)). Analysis so far showed that ON1 (with a seventy-two nucleotide duplication in attachment protein G) is the most common genotype in both community and hospitalized samples (90% and 75% of samples, respectively), with GA2 (without duplication) as the next most common genotype for RSV A subtypes (7% and 25%). Three per cent of community samples were of the GA5 genotype. Samples from the RSV B subgroup all belong to the BA genotypes with a 60-nucleotide duplication in G. Samples that were selected for Illumina sequencing had a Ct value between 19.0 and 29.1, while hospital samples had a Ct value of 18.3 to 29.1. Viral load, therefore, did not explain disease severity in these selected samples. The Shannon entropy from Illumina sequenced samples averaged at 22.78 in community samples (ranges from 15 to 28) and 38.78 in hospitalized samples (ranges from 31 to 57). This indicated that diversity of the virus pool might influence disease severity; however, more samples need to be analyzed. There are no specific variants that could explain disease severity. Diversity of the virus pool could explain the link between higher viral loads and disease severity, which is sometimes found but cannot always be confirmed. Higher viral loads can harbor more diverse viral particles compared to lower viral loads. Future work will focus on more in-depth variation and diversity analysis and on evolutionary analysis of both community and hospital samples. We will also investigate intra-host evolution of RSV in acute infections using consecutive samples and its possible implications on the host response.

Download Full-text

Antiviral Efficacy of a Respiratory Syncytial Virus (RSV) Fusion Inhibitor in a Bovine Model of RSV Infection

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00487-15 ◽

2015 ◽

Vol 59 (8) ◽

pp. 4889-4900 ◽

Cited By ~ 14

Author(s):

Robert Jordan ◽

Matt Shao ◽

Richard L. Mackman ◽

Michel Perron ◽

Tomas Cihlar ◽

...

Keyword(s):

Viral Load ◽

Respiratory Syncytial Virus ◽

Structural Analog ◽

Therapeutic Benefit ◽

Viral Envelope ◽

Fusion Inhibitor ◽

Lung Pathology ◽

Host Cell Membrane ◽

Rsv Infection ◽

Syncytial Virus

ABSTRACTRespiratory syncytial virus (RSV) is the leading cause of bronchiolitis and pneumonia in infants. Effective treatment for RSV infection is a significant unmet medical need. While new RSV therapeutics are now in development, there are very few animal models that mimic the pathogenesis of human RSV, making it difficult to evaluate new disease interventions. Experimental infection of Holstein calves with bovine RSV (bRSV) causes a severe respiratory infection that is similar to human RSV infection, providing a relevant model for testing novel therapeutic agents. In this model, viral load is readily detected in nasal secretions by quantitative real-time PCR (qRT-PCR), and cumulative symptom scoring together with histopathology evaluations of infected tissue allow for the assessment of disease severity. The bovine RSV model was used to evaluate the antiviral activity of an RSV fusion inhibitor, GS1, which blocks virus entry by inhibiting the fusion of the viral envelope with the host cell membrane. The efficacy of GS1, a close structural analog of GS-5806 that is being developed to treat RSV infection in humans was evaluated in two randomized, blind, placebo-controlled studies in bRSV-infected calves. Intravenous administration of GS1 at 4 mg/kg of body weight/day for 7 days starting 24 h or 72 h postinoculation provided clear therapeutic benefit by reducing the viral load, disease symptom score, respiration rate, and lung pathology associated with bRSV infection. These data support the use of the bovine RSV model for evaluation of experimental therapeutics for treatment of RSV.

Download Full-text