Respiratory Syncytial Research Articles

Circulating respiratory viruses including SARS-CoV-2 during 2021-2022 season in Tunisia: Epidemiological and dynamic changes

BackgroundChanging patterns in community respiratory virus activity were reported in different geographical locations during the COVID-19 pandemic. In this study, we aimed to assess the prevalence of circulating respiratory viruses, including SARS-CoV-2, during the season 2021-2022 in Tunisia. MethodsWe retrospectively enrolled 328 nasopharyngeal samples received at the Triage Center of Habib Bourguiba Hospital from patients with acute respiratory symptoms during September 2021-May 2022. All samples were screened for both SARS-CoV-2 and common respiratory viruses. This latter detection was performed using end-point multiplex RT-PCRs, Real-Time PCR, and AllplexTM Respiratory Panel 1 kit (Seegene) for Influenza Virus A (IFVA) and Respiratory Syncytial Virus (RSV) subtyping. ResultsAmong included patients, at least one viral pathogen was identified in 118 (35.9%) patients. The detection rate of SARS-CoV-2 was 21.6%. A low viral coinfection rate was observed (3.3%). The most prevalent pathogen among non-SARS-CoV-2 viruses was Enterovirus/Rhinovirus (HEV/HRV) (59.6%) followed by IFVA (15.3%) and Adenoviruses (ADV) (11.5%). Only IFVA H3N2 was found to circulate during the study period. A negative virus interaction was eventually induced by SARS-CoV-2, as it was shown by lower levels of activity of non-SARS-CoV-2 viruses (not exceeding 17.7%) while infections due to pandemic Omicron variants of concern became widespread. ConclusionsThis study highlights the relative return of community IFVA circulation during the 2021-2022 season in Tunisia. A negative viral interaction between SARS-CoV-2 and other respiratory viruses is highly suggested, which explains, in addition to the easing of COVID-19 restriction measures, the epidemiological changes in non-SARS-CoV-2 viruses circulation.

Spectrum of respiratory viruses identified from SARS-CoV-2-negative human respiratory tract specimens in Watansoppeng, Indonesia.

Respiratory infections account for millions of hospital admissions worldwide. The aetiology of respiratory infections can be attributed to a diverse range of pathogens including viruses, bacteria and fungi. SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2)-negative specimens from Wattansoppeng city, South Sulawesi, were analysed to study the spectrum of respiratory viruses. Samples were screened for influenza virus, enterovirus, Paramyxoviridae, Nipah virus, Coronaviridae and Pneumoviridae. Of 210 specimens, 19 were positive for respiratory syncytial virus (RSV)-A, RSV-B, human parainfluenza virus type 1 (HPIV-1), HPIV-2, human rhinovirus (HRV)-A, HRV-B, HRV-C, human metapneumovirus (HMPV), influenza A virus (IAV) and coxsackievirus A6 (CV-A6). Influenza virus was of seasonal H3N2 subtype. The HMPVs were of genotypes B1 and A2a, while one RSV-A was of the ON-1 genotype. The viruses mostly affected children with unknown severity.

Chiral Intranasal Nanovaccines as Antivirals for Respiratory Syncytial Virus.

This study aimed to develop an intranasal nanovaccine by combining chiral nanoparticles with the RSV pre-fusion protein (RSV protein) to create L-nanovaccine (L-Vac). The results showed that L-NPs increased antigen attachment in the nasal cavity by 3.83 times and prolonged its retention time to 72h. In vivo experimental data demonstrated that the intranasal immunization with L-Vac induced a 4.86-fold increase in secretory immunoglobulin A (sIgA) secretion in the upper respiratory tract, a 1.85-fold increase in the lower respiratory tract, and a 20.61-fold increase in RSV-specific immunoglobin G (IgG) titer levels in serum, compared with the commercial Alum Vac, while the neutralizing activity against the RSV authentic virus is 1.66-fold higher. The mechanistic investigation revealed that L-Vac activated the tumor necrosis factor (TNF) signaling pathway in nasal epithelial cells (NECs), in turn increasing the expression levels of interleukin-6 (IL-6) and C-C motif chemokine ligand 20 (CCL20) by 1.67-fold and 3.46-fold, respectively, through the downstream nuclear factor kappa-B (NF-κB) signaling pathway. Meanwhile, CCL20 recruited dendritic cells (DCs) and L-Vac activated the Toll-like receptor signaling pathway in DCs, promoting IL-6 expression and DCs maturation, and boosted sIgA production and T-cell responses. The findings suggested that L- Vac may serve as a candidate for the development of intranasal medicine against various types of respiratory infections.

Risk factors for poor outcome in adult patients with respiratory syncytial virus infection evaluated at the emergency department.

Respiratory syncytial virus-associated acute respiratory infection (RSV-ARI) constitutes an emerging cause of morbidity in the adult population. The present retrospective study was aimed at identifying factors predictive of poor outcome that may be assessed at the first evaluation in the Emergency Department (ED). We included 275 adult patients with laboratory-confirmed RSV-ARI that required hospital admission from the ED between January 2018 and December 2019. Poor outcome (composite of progression to high-flow oxygen therapy, non-invasive or invasive mechanical ventilation, or intensive care unit admission, and/or 30-day all-cause mortality) occurred in 31 patients (11.2%). Immunosuppression was present in 59 patients (21.5%). Although bacterial co-infection was rare, antibiotic therapy was commonly initiated. Ribavirin was administered in 10 patients. Cognitive impairment (odds ratio [OR]: 2.452; 95% confidence interval [CI]: 0.990-6.072), concurrent oral anticoagulation (OR: 3.099; 95 CI: 1.287-7.464) and a pulse oximetry oxygen saturation to fraction of inspired oxygen ratio (SpO2/FiO2) ratio <382 at ED admission (OR: 3.013; 95 CI: 1.306-6.950) were independent risk factors for poor outcome, whereas influenza vaccination in the current season was protective (OR: 0.324; 95% CI: 0.138-0.763). Various factors easily available at the ED are useful for early risk stratification in adult patients with RSV-ARI.

S1048 Respiratory Syncytial Virus Vaccine is Associated With Better Outcomes in Inflammatory Bowel Disease Patients over 60 Years Old: A US Propensity-Matched Study

S1048 Respiratory Syncytial Virus Vaccine is Associated With Better Outcomes in Inflammatory Bowel Disease Patients over 60 Years Old: A US Propensity-Matched Study

S1897 Liver Cirrhosis and its Impact on Clinical Outcomes in Adult Respiratory Syncytial Virus Pneumonia: A Retrospective Analysis of the National Inpatient Sample

S1897 Liver Cirrhosis and its Impact on Clinical Outcomes in Adult Respiratory Syncytial Virus Pneumonia: A Retrospective Analysis of the National Inpatient Sample

Molecular surveillance in the nirsevimab era: lessons from respiratory syncytial virus breakthrough infections

Molecular surveillance in the nirsevimab era: lessons from respiratory syncytial virus breakthrough infections

Preventing respiratory syncytial virus in infants.

Preventing respiratory syncytial virus in infants.

Intracellular delivery of antiviral shRNA using penetratin-based complexes effectively inhibits respiratory syncytial virus replication and host cell apoptosis

BackgroundCell-penetrating peptides (CPPs) are effective for delivering therapeutic molecules with minimal toxicity. This study focuses on the use of penetratin, a well-characterized CPP, to deliver a DNA vector encoding short hairpin RNA (shRNA) targeting the respiratory syncytial virus (RSV) F gene into infected cells. RSV is known to cause severe lower respiratory infections in infants and poses significant risks to immunocompromised individuals and the elderly. We evaluated the antiviral efficacy of the penetratin-shRNA complex by comparing its ability to inhibit RSV replication and induce apoptosis with ribavirin treatment.MethodsPenetratin-shRNA complexes were prepared at different ratios and analyzed using gel retardation assays, dynamic light scattering, and zeta potential measurements. The complexes were tested in HEp-2 and A549 cells for transfection efficiency, cytotoxicity, viral load, and apoptosis using plaque assays, real-time reverse transcription-polymerase chain reaction (RT-PCR), DNA fragmentation, propidium iodide staining, and caspase 3/7 activation assays.ResultsThe gel shift assay determined that a 20:1 CPP-to-shRNA ratio was optimal for effective complexation, resulting in particles with a size of 164 nm and a zeta potential of 8.7 mV. Transfection efficiency in HEp-2 cells was highest at this ratio, reaching up to 93%. The penetratin-shRNA complex effectively silenced the RSV F gene, reduced viral titers, and decreased DNA fragmentation and apoptosis in infected cells.ConclusionPenetratin effectively delivers shRNA targeting the RSV F gene, significantly reducing viral load and preventing apoptosis without toxicity. This approach surpasses Lipofectamine and shows potential for future therapeutic interventions, especially when combined with ribavirin, against RSV infection.Graphical

Respiratory syncytial virus infection notification trends and interpretation of the reported case data, 2018-2021, Japan.

In Japan, as elsewhere, the COVID-19 pandemic affected the notification trends of respiratory syncytial virus (RSV) infection. Here, we describe the epidemiological trends of RSV cases among children reported during 2018-2021 in Japan, based on the national surveillance system. Compared to 2018 and 2019, 2020 saw an unprecedented decrease in RSV notifications per sentinel site. However, 2021 experienced an unseasonably early and high peak in week 28 (peak week in 2018 and 2019: week 37) with a large resurgence in notifications, nationwide and across regions. Regarding age, compared to 2018 and 2019, the number and proportion of cases aged 2, 3, and ≥4-years increased substantially in 2021 but the number of cases aged <1 year decreased slightly. Furthermore, in 2021, the ratio of notifications per site from outpatient clinics to hospitals increased, suggesting a proportionate increase in clinically milder case diagnoses. Notably, RSV-attributed deaths from vital statistics also dropped substantially in 2020 and rebounded in 2021, but were fewer than in 2018 or 2019. While RSV incidence likely declined in 2020 (possibly from COVID-19 countermeasures) and increased in 2021, notifications in 2021 appeared to be associated with milder presentations. Given unpredictable RSV epidemiology, continuous monitoring and pluralistic assessments are imperative.

Integrated environmental and clinical surveillance for the prevention of acute respiratory infections (ARIs) in indoor environments and vulnerable communities (Stell-ARI): Protocol.

The epidemiological relevance of viral acute respiratory infections (ARIs) has been dramatically highlighted by COVID-19. However, other viruses cannot be neglected, such as influenza virus, respiratory syncytial virus, human adenovirus. These viruses thrive in closed spaces, influenced by human and environmental factors. High-risk closed communities are the most vulnerable settings, where the real extent of viral ARIs is often difficult to evaluate, due to the natural disease progression and case identification complexities. During the COVID-19 pandemic, wastewater-based epidemiology has demonstrated its great potential for monitoring the circulation and evolution of the virus in the environment. The "Prevention of ARIs in indoor environments and vulnerable communities" study (Stell-ARI) addresses the urgent need for integrated surveillance and early detection of ARIs within enclosed and vulnerable communities such as long-term care facilities, prisons and primary schools. The rapid transmission of ARIs in such environments underscores the importance of comprehensive surveillance strategies to minimise the risk of outbreaks and safeguard community health, enabling proactive prevention and control strategies to protect the health of vulnerable populations. This study consists of designing and validating tools for integrated clinical and environmental-based surveillance for each setting, coupled with analytical methods for environmental matrices. The clinical surveillance involves specialized questionnaires and nasopharyngeal swabs for virus identification, while the environmental surveillance includes air and surface microbiological and chemical monitoring, and virological analysis of wastewater. Integrating this information and the collection of behavioural and environmental risk factors into predictive and risk assessment models will provide a useful tool for early warning, risk assessment and informed decision-making. The study aims to integrate clinical, behavioural, and environmental data to establish and validate a predictive model and risk assessment tool for the early warning and risk management of viral ARIs in closed and vulnerable communities prior to the onset of an outbreak.

Antibiotic use in a co-infection of respiratory syncytial virus and pathogenic bacteria in children in a resource-limited setting in northeast Peninsular Malaysia.

To investigate co-infection of bacterial isolates associated with respiratory syncytial virus (RSV) in children aged less than two years who were admitted to hospital with confirmed lower respiratory tract infection (LRTI) in Kelantan, Malaysia. The demographic data, clinical history, case management, haematological as well as infectious parameters (white blood cell differential and count, plus C-reactive protein, CRP) of the patients were systematically recorded. Less than one-third of cases were RSV-positive (21.03% and 26.23% were diagnosed as acute bronchiolitis or pneumonia, respectively). Blood cultures from approximately 10% of patients demonstrated growth of Haemophilus influenzae, Staphylococcus aureus, coagulase-negative Staphylococcus, Pseudomonas stutzeri, haemolytic Streptococcus group A, and Bacillus subtilis. Further analysis indicated that children with positive bacterial growth had an insignificant predictive value of CRP (2.32-7.16 mg/dl). The total white cell counts were 2.97-7.33 x 109sup>/L despite increased lymphocyte values in the bacteria-positive blood culture. Platelet counts were also within normal limits except for a single case of H. influenzae infection (685.50 x 109sup>/L). Interestingly, 95.01% of patients were treated with antibiotics; 66.23% of RSV infection cases were administered with a combination of antibiotics and 33.77% with only a single antibiotic. The data indicate that the use of antibiotics, either singly or in combination, is not always effective in treating LRTI in infants. Alternative therapeutic regimens should be considered, especially in Asian countries that may have limited resources.

Ethanolic Extract from Echinacea purpurea (L.) Moench Inhibits Influenza A/B and Respiratory Syncytial Virus Infection in vitro: Preventive Agent for Viral Respiratory Infections.

Among the most frequent causes of respiratory infections in humans are influenza A virus H1N1 (H1N1), influenza B virus (IVB), and respiratory syncytial virus (RSV). Echinacea is a perennial wildflower belonging to the Asteraceae family. Echinacea purpurea (L.) Moench is a species belonging to the Echinacea genus. Its characteristic compound, chicoric acid (CA), is known for its physiological activities, including antiviral effects and immune enhancement. Activities of E. purpurea 60% ethanol extract (EPE) and CA in inhibiting infections caused by H1N1, IVB, and RSV subtype A (RSV-A) were evaluated through plaque inhibition tests, quantification of viral gene expression, and analysis of transmission electron microscopy (TEM) images. Additionally, inhibitory activities of EPE and CA for hemagglutination and neuraminidase (NA) of H1N1 and IVB were determined. In the plaque reduction assays, both EPE and CA reduced infectivity against H1N1, IVB, and RSV-A. Furthermore, quantitative real-time polymerase chain reaction analysis revealed that EPE and CA reduced gene expression levels for H1N1, IVB, and RSV-A, whereas TEM image analysis confirmed their inhibitory effects on host cell infection by these viruses. Hemagglutination assays exhibited the ability of EPE and CA to hinder H1N1 and IVB attachment to host cell receptors. Furthermore, EPE and CA displayed inhibition activity against the NA of H1N1 and IVB. These findings suggest that EPE and CA can suppress the infection and propagation of H1N1, IVB, and RSV-A, demonstrating their potential as preventive and therapeutic agents for viral respiratory infections or as ingredients for health functional foods.

Reduced antiviral gene expression and elevated CXCL8 expression in peripheral blood are associated with severe hypoxemia in RSV-infected children.

The pathology of respiratory syncytial virus (RSV) infection remains unclear. An unbalanced immune response to RSV infection can lead to immunopathology, causing airway damage and impaired exchange of oxygen and carbon dioxide between the air and the bloodstream. We aimed to evaluate the association of the expression of inflammatory and antiviral genes in peripheral blood with severe hypoxemia in children with RSV infection seen in the hospital emergency room. We conducted a cross-sectional study on 121 RSV-infected children seen in hospital emergency rooms between 2015 and 2023. Total RNA was extracted from whole blood samples, and gene expression (IL-6, TNFα, CXCL8, ISG15, IFIT1, RIGI, IFNβ, CCL5, and CXCL10) was quantified using quantitative RT-PCR. The outcome variable was having severe hypoxemia (SpO2 ≤ 90%). The association analysis was performed using a volcano plot, adjusted logistic regression, and orthogonal partial least squares discriminant analysis (OPLS-DA). We found that 26 of 121 children had severe hypoxemia (SpO2 ≤ 90%). CXCL8 was overexpressed [fold changes (FC) > 2; q-value < 0.05], and ISG15, IFIT1, RIGI, IFNβ, CCL5, and CXCL10 were underexpressed (FC <0.5; q-value <0.05) in children with severe hypoxemia. These associations were ratified using adjusted logistic regression. The OPLS-DA showed that the gene expressions of CXCL8, ISG15, IFIT1, RIGI, and CXCL10 had values of variable importance in projection (VIP) ≥1, being the most relevant features. In conclusion, an imbalance favoring inflammation over antiviral defense may contribute to the pathogenesis of severe hypoxemia in RSV-infected children. These findings provide valuable insights into the pathology of RSV infection.

Molecular Investigation of Seven Respiratory Viruses in Patients with Acute Respiratory Tract Infections

Introduction: Respiratory tract infection (RTI) is among the important factors that can threaten human health and is one of the most prevalent etiological agents of death, especially in young children. Viruses account for approximately 80% of various RTIs worldwide. Our study aimed to investigate the molecular prevalence of seven respiratory viruses in RTI. Our results can help develop appropriate public health strategies and treatment management of RTIs. Materials and Methods: 120 respiratory samples were obtained from patients with flu-like manifestations from hospitals referred to the Iran University of Medical Sciences during 2020-2022. Nucleic acid extraction was performed, and then real-time polymerase chain reaction was performed to analyze the specimens to investigate seven respiratory viruses. Results: Of the 120 respiratory specimens collected from patients with RTI, viruses were identified in 41 (34.16%) samples, encompassing 24 (40.7%) females and 17 (27.9%) males. SARS-CoV-2 (n = 22, 18.3%) and Parainfluenza virus (n=18, 15%) were the predominant detected viruses in the present study, followed by respiratory syncytial viruses (n=1, 0.8%). Other viruses like Metapneumovirus, Adenovirus, Bocavirus, and Rhinovirus were not found in our study. We could not detect any co-infection in our analysis. Conclusion: SARS-CoV-2 and Parainfluenza-virus were the predominant viruses detected in our study, followed by respiratory syncytial viruses. Other viruses, such as Metapneumovirus, Adenovirus, Bocavirus, and Rhinovirus, have not been found in our study. We could not detect any co-infection in our consideration. This result can help develop appropriate public health strategies, targeting prevention and avoiding inappropriate treatment such as using unnecessary antibiotics.

Introduction of nirsevimab in Catalonia, Spain: description of the incidence of bronchiolitis and respiratory syncytial virus in the 2023/2024 season.

Respiratory syncytial virus (RSV) causes most of the cases of bronchiolitis and thousands of deaths annually, particularly in infants less than 6months old. In Catalonia (Spain), infants born between April 2023 and March 2024 aged 0-6months during their first RSV season have been candidates to receive nirsevimab, the novel monoclonal antibody against RSV, since October 2023. We aimed to analyse the dynamics of all-causes bronchiolitis diagnoses and RSV community infections in the current season and compare them to pre-nirsevimab epidemics. We collected epidemiological data from the Information System for Surveillance of Infections in Catalonia (SIVIC) on daily all-causes bronchiolitis clinical diagnoses and RSV-confirmed cases provided by rapid antigen tests in primary care practices. We calculated the rate ratio (RR) for the incidence of all-causes bronchiolitis for children aged 0-11m-old with respect to 12-35m-old between September 2014 and January 2024. We analysed the RR of the incidence of RSV-confirmed infection for 0-11m-old and 12-35m-old with respect to the > 35m-old, from January 2021 to January 2024. We then computed the relative difference of the RR, designated as percentage of reduction of risk, between season 2023/2024 and former epidemics. With a global coverage recorded rate for nirsevimab of 82.2% in January 2024, the age-specific 0-11m-old RR (95% CI) of RSV infection incidence for > 35m-old was 1.7 (1.5-2.0) in season 2023/2024. The RR (95% CI) had been 7.4 (5.6-9.9), 8.8 (6.9-11.3), and 7.1 (5.7-8.9) in 2020/2021, 2021/2022, and 2022/2023, respectively. Regarding the incidence of all-causes bronchiolitis for the 0-11m-old group compared to the 12-35m-old, the pre-pandemic (2014/2015-2019/2020) and 2022/2023 RR (95% CI) were 9.4 (9.2-9.6) and 6.0 (5.7-6.2), respectively, significantly higher than the RR of 3.6 (3.4-3.8) for the most recent season, 2023/2024. Conclusion: Concurring with the introduction of nirsevimab, the risk of RSV infection for infants aged 0-11m-old compared to > 35m-old has been reduced by 75.6% (73.4-77.5) in last season, and the risk for all-causes bronchiolitis for 12-35m-old by 61.9% (60.9-62.9) from the pre-pandemic period and by 39.8% (39.3-40.2) from the 2022/2023 epidemic, despite high RSV community transmission, especially in older infants What is Known: • RSV is responsible for approximately 70% of bronchiolitis cases and causes severe disease, particularly in infants < 6months of age. • Nirsevimab effectiveness against RSV-associated disease, particularly hospitalisations, was expected to be around 80%; other Spanish regions, such as Galicia and Valencia, and European countries including Luxembourg and Germany, have already reported good results in implementing nirsevimab to prevent RSV-associated hospitalisations and PICU stays. What is New: • We provide insight into the community incidence of RSV and all-causes bronchiolitis for season 2023/2024, when nirsevimab has been introduced to the Catalan population, using. primary healthcare data, which enabled us to assess the burden of RSV infections and bronchiolitis in the commonly seasonally saturated primary healthcare practices. • Our study reveals that the risk of all-causes bronchiolitis for infants aged 0-11m-old compared to older infants was reduced by 40% compared to the previous season and 62% compared to pre-pandemic standards, and for RSV infection it was reduced by 76%.

Burden of Illness Associated With Respiratory Syncytial Virus, Influenza, and Coronavirus Disease 2019 in Infants and Young Children in Ontario, Canada, 2018-2023: A Population-Based Canadian Immunization Research Network Study.

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transitions to endemicity and respiratory syncytial virus (RSV) and influenza reestablish their seasonal circulation patterns, understanding their comparative burden on infants and children can guide health system responses and funding priorities. This was a population-based cohort study of children aged <5 years in Ontario, Canada, from September 2018 to August 2023 using linked health administrative databases. Seasonal cohorts comprised 731 838 to 763 660 children. RSV- and influenza-related hospital admission rates immediately decreased in March 2020. In 2021-2022, RSV-related admissions rebounded but remained 8%-11% lower than prepandemic seasons, whereas 2022-2023 RSV-related admissions increased 105%-113% versus prepandemic seasons and peak admissions occurred in November versus December. Influenza did not rebound until 2022-2023, when admissions were 28%-37% higher than prepandemic seasons. Coronavirus disease 2019 (COVID-19)-related admissions remained low until 2021-2022 and were lower than RSV-related admissions across all age groups during prepandemic and pandemic seasons. By contrast, 2021-2022 COVID-19-related admissions exceeded prepandemic influenza-related admissions by 30%-40% but decreased by 45% in 2022-2023 and were lower than prepandemic influenza-related admissions, except among infants aged <12 months who remained at highest risk. There was no distinct seasonal pattern for COVID-19-related admissions during the study. RSV remains a major cause of childhood hospitalization. Although COVID-19 appears to be receding, its disease burden as it transitions to endemicity remains to be established. The unprecedented peaks in RSV-related hospital admissions during 2022-2023, together with the return of influenza and ongoing SARS-CoV-2 transmission, underscore the need to strengthen systems for real-time surveillance and to proactively prepare for critical healthcare scenarios.

The Prognosis in Children With Pneumonia of Respiratory Syncytial Virus Co-detection With Airway Dominant Flora.

Airway bacterial microbiota influences the prognosis in children with respiratory syncytial virus infection. The study aimed to investigate the effect of the airway-dominant bacterial microbiota on disease severity in children with pneumonia of respiratory syncytial virus infection. A retrospective study was conducted in the Children's Hospital of Chongqing Medical University, which involved a cohort of patients with respiratory syncytial virus (RSV)-infected pneumonia from January 2012 to December 2021. Patients were assigned to a normal flora group or to a dominant flora group (with the top 5 individual bacteria) based on the nasopharyngeal aspirates culture and matched using propensity-score matching. Univariate analysis and multivariate analysis were performed to estimate the risk factors of poor prognosis in dominant flora. Five thousand five hundred and twelve patients in the normal flora and 4556 in the dominant flora were included ( Escherichia coli 514, Streptococcus pneumoniae 1516, Staphylococcus aureus 506, Moraxella catarrhalis 509 and Haemophilus influenzae 1516, respectively). The dominant flora had more patients developing severe pneumonia, needing mechanical ventilation/tracheal intubation (up to 15.8% in the S. aureus ) and admission to the intensive care unit (up to 4.5% in the E. coli ) than in the normal flora (28.5% vs. 25.9%; P = 0.001; 9.8% vs. 5.4%; P < 0.001; 2.0% vs. 1.2%; P <0.001). And the hospitalization was longer in the dominant flora than in the normal flora [8 (6-9) vs. 8 (7-9) days; P < 0.001], the E. coli and S. aureus had the longest hospitalization [8 (7-10) days]. Several factors were associated with critical illness in Dominant flora according to multivariate analysis ( P < 0.001), including age (OR: 0.965; CI: 0.954-0.976; P < 0.001), anhelation (OR: 0.530; CI: 0.446-0.631; P < 0.001), disorders of consciousness (OR: 0.055; CI: 0.016-0.185; P < 0.001) as well as assisted respiration (OR: 0.115; CI: 0.097-0.138; P < 0.001), C-reactive protein >10 mg/L (OR: 0.686; CI: 0.560-0.839; P < 0.001), SpO 2 <90% (OR: 0.366; CI: 0.214-0.628; P < 0.001), pulmonary consolidation (OR: 0.511; CI: 0.364-0.717; P < 0.001) and pulmonary atelectasis (OR: 0.362; CI: 0.236-0.555; P < 0.001). The airway-dominant bacterial microbiota influenced disease severity and comorbidities in children with RSV-infected pneumonia. Clinicians should pay attention to the nasopharyngeal aspirate culture, especially after detecting S. aureus and E. coli in RSV-infected children with pneumonia, closely observe the disease progression and take timely measures to avoid adverse outcomes.

Mutating a flexible region of the RSV F protein can stabilize the prefusion conformation.

The respiratory syncytial virus (RSV) fusion (F) glycoprotein is highly immunogenic in its prefusion (pre-F) conformation. However, the protein is unstable, and its conformation must be stabilized for it to function effectively as an immunogen in vaccines. We present a mutagenesis strategy to arrest the RSV F protein in its pre-F state by blocking localized changes in protein structure that accompany large-scale conformational rearrangements. We generated a series of mutants and screened them in vitro to assess their potential for forming a stable pre-F. In animals, the immunogenicity of a representative mutant F protein, with a conformation confirmed by cryo-electron microscopy, elicited levels of neutralizing antibodies and protection against RSV-induced lung damage that were comparable to those of DS-Cav1, a pre-F used in a licensed vaccine.

Incidence of Respiratory Syncytial Virus in Community-Dwelling Adults Aged 18-64 Years Over 2 Seasons, 2022-2024, in a North American Community.

The incidence of respiratory syncytial virus (RSV)-acute respiratory infection (ARI) in community-dwelling adults after the Omicron variant of the COVID-19 pandemic is unknown. Our aim was to assess the incidence of RSV-ARI in adults aged 18 to 64 years over 2 consecutive RSV seasons (October-April 2022-2024) in 4 US states. This community-based prospective cohort study comprised 7501 participants in Minnesota, Wisconsin, Florida, and Arizona. We calculated RSV-ARI and RSV-lower respiratory tract disease (LRTD) incidence and attack rates. We reported unadjusted incidence by age group, gender, race and ethnicity, Charlson Comorbidity Index, socioeconomic status, residential state, and rural/urban setting. Seasons 1 and 2 had 2250 and 2377 ARI episodes, respectively, with an RSV-ARI positivity rate of 5.5% for season 1 and 5.8% for season 2 among those tested. In season 1, the overall incidence of RSV-ARI was 27.71 (95% CI, 22.82-33.34) per 1000 person-years (1.49% attack rate). Almost half (49.0%) had RSV-LRTD, with an incidence of 13.53 (95% CI, 10.19-17.61) per 1000 person-years (0.73% attack rate). In season 2, the RSV-ARI and RSV-LRTD incidence rates were 26.39 (95% CI, 21.73-31.75) per 1000 person-years (1.51% attack rate) and 12.43 (95% CI, 9.31-16.26) per 1000 person-years (0.72% attack rate). RSV-ARI incidence peaked in November 2022 and December 2023. Our observations suggest that RSV-ARI incidence and seasonal pattern are shifting to prepandemic RSV epidemiology.