Respiratory syntycial virus: Current treatment strategies and vaccine approaches

Nei-like DNA glycosylase 2 selectively antagonizes interferon-β expression upon respiratory syncytial virus infection

As part of the antiviral response, cells activate the expressions of type I interferons (IFNs) and proinflammatory mediators to control viral spreading. Viral infections can impact DNA integrity; however, how DNA damage repair coordinates antiviral response remains elusive. Here we report Nei-like DNA glycosylase 2 (NEIL2), a transcription-coupled DNA repair protein, actively recognizes the oxidative DNA substrates induced by respiratory syncytial virus (RSV) infection to set the threshold of IFN-β expression. Our results show that NEIL2 antagonizes nuclear factor κB (NF-κB) acting on the IFN-β promoter early after infection, thus limiting gene expression amplified by type I IFNs. Mice lacking Neil2 are far more susceptible to RSV-induced illness with an exuberant expression of proinflammatory genes and tissue damage, and the administration of NEIL2 protein into the airway corrected these defects. These results suggest a safeguarding function of NEIL2 in controlling IFN-β levels against RSV infection. Due to the short- and long-term side effects of type I IFNs applied in antiviral therapy, NEIL2 may provide an alternative not only for ensuring genome fidelity but also for controlling immune responses.

Responding to Higher-Than-Expected Infant Mortality Rates from Respiratory Syncytial Virus (RSV): Improving Treatment and Reporting Strategies

Respiratory syncytial virus (RSV) has a major role in respiratory infections in young infants around the world. However, substantial progress has been made in recent years in the field of RSV. A wide variety of observational studies and clinical trials published in the past decade provide a thorough idea of the health and economic burden of RSV disease in the developing world. In this review, we discuss the impact of RSV burden of disease, major gaps in disease estimations, and challenges in generating new therapeutic options and an immune response against the virus, and briefly describe next generation technologies that are being evaluated.

Estimating the burden of adult hospitalized RSV infection using local and state data - methodology

Respiratory syncytial virus (RSV) is becoming increasingly recognized as a serious threat to vulnerable population subgroups. This study describes the statistical analysis plan for a retrospective cohort study of adults hospitalized for acute respiratory infection (ARI) to estimate the population burden of RSV especially for groups such as the elderly, pregnant women and solid organ transplant patients. Disease burden estimates are essential for setting vaccine policy, e.g., should RSV vaccine become available, burden estimates may inform recommendations to prioritize certain high-risk groups. The study population is residents of Allegheny County, Pennsylvania ≥18 years of age who were hospitalized in Pennsylvania during the period September 1, 2015–August 31, 2018. Data sources will include U.S. Census, Pennsylvania Health Care Cost Containment Council (PHC4) and the electronic medical record for the health system to which the hospitals belong. The algorithm involves: 1) ARI-associated hospitalizations in PHC4 data; 2) adjustment for ARI hospitalizations among county residents but admitted to hospitals outside the county; and 3) RSV detections from respiratory viral panels. Key sensitivity analyses will adjust for undertesting for viruses in the fall and spring quarters. The results will be population-based estimates, stratified by age and risk groups. Adjusting hospitalization data using a multiplier method is a simple means to estimate the impact of RSV in a given area. This algorithm can be applied to other health systems and localities to estimate RSV and other respiratory pathogen burden in adults, to estimate burden following introduction of RSV vaccine and to make cost-effectiveness estimates.

Investigation of the Fuzzy Complex between RSV Nucleoprotein and Phosphoprotein to Optimize an Inhibition Assay by Fluorescence Polarization

The interaction between Respiratory Syncytial Virus phosphoprotein P and nucleoprotein N is essential for the formation of the holo RSV polymerase that carries out replication. In vitro screening of antivirals targeting the N-P protein interaction requires a molecular interaction model, ideally consisting of a complex between N protein and a short peptide corresponding to the C-terminal tail of the P protein. However, the flexibility of C-terminal P peptides as well as their phosphorylation status play a role in binding and may bias the outcome of an inhibition assay. We therefore investigated binding affinities and dynamics of this interaction by testing two N protein constructs and P peptides of different lengths and composition, using nuclear magnetic resonance and fluorescence polarization (FP). We show that, although the last C-terminal Phe₂₄₁ residue is the main determinant for anchoring P to N, only longer peptides afford sub-micromolar affinity, despite increasing mobility towards the N-terminus. We investigated competitive binding by peptides and small compounds, including molecules used as fluorescent labels in FP. Based on these results, we draw optimized parameters for a robust RSV N-P inhibition assay and validated this assay with the M76 molecule, which displays antiviral properties, for further screening of chemical libraries.

Real-World Studies of Respiratory Syncytial Virus Hospitalizations among Moderate/Late Preterm Infants Exposed to Passive Immunoprophylaxis with Palivizumab

This article aims to assess the real-world effectiveness of palivizumab immunoprophylaxis against respiratory syncytial virus (RSV)-associated hospitalization (RSVH) rates in otherwise healthy moderate/late preterm infants and discuss the role of palivizumab in preventing acute and long-term outcomes. We identified studies in the PubMed and Embase databases that reported patient-level data on (1) exposure to palivizumab in preterm infants born between 29 and 35 weeks of gestational age (or subsets within this range) ≤ 2 years of chronological age, and (2) the outcome of RSVH. Six studies assessed RSVH in infants this gestational age who had been exposed or not to palivizumab and reported patient-level data. Exposure was associated with a reduction in RSVH rates that was comparable to the reduction seen in controlled clinical trials (weighed mean 4.0-fold reduction). RSV immunoprophylaxis in preterm infants within 29 to 35 weeks of gestational age is associated with a considerably lower burden of RSVH. KEY POINTS: · RSV is the leading cause of lower respiratory tract infection hospitalization in infants.. · Palivizumab prevents RSVH in a real-world scenario.. · Immunoprophylaxis should be used in high-risk infants..

Impact of Respiratory Syncytial Virus and Influenza Virus Infection in the Adult Population in Spain between 2012 and 2020

Respiratory syncytial virus (RSV) infection is increasingly recognized as a cause of significant morbidity and mortality in adults. We aimed to estimate the rates of age-specific hospitalization and in-hospital mortality caused by acute lower respiratory tract infections (ALRTIs) in Spain between 2012 and 2020 and to compare the relative impact of RSV and influenza virus infection in adults. We used the discharge reports from the Minimum Basic Data Set to retrospectively analyze hospital discharge data on the basis of the ICD-9-CM and ICD-10-CM diagnosis codes. A total of 1,518,244 patients were hospitalized for ALRTIs, of whom 137,794 (9.1%) were admitted for RSV-related infections and 46,288 (3.0%) for influenza-related infections. In patients aged 60 years or older, the hospitalization rates (per 100,000 population) were estimated at 1.69 (95% CI 1.68-1.70) and 2.72 (95% CI 2.71-2.73) for RSV and influenza patients, respectively. However, in-hospital mortality rates were significantly higher among RSV patients than among influenza patients, 7.91% (95% CI 7.89-7.93) (83.0% of all RSV-related deaths) versus 6.91% (95% CI 6.89-6.93) (85.6% of all influenza-related deaths), respectively (p = 0.007). RSV-associated in-hospital mortality increases exponentially with age, posing a greater risk for older adults, particularly frail and high-risk patients.