Respiratory Syncytial Virus Antigen Research Articles

Respiratory Syncytial Virus Infection in Children with Bronchiolitis

Background: Respiratory Syncytial Virus (RSV) is the most common organism causing bronchiolitis. Bronchiolitis is almost always diagnosed clinically. As a result, the availability of bedside sensitive rapid RSV antigen tests is critical for timely RSV acute respiratory infection diagnosis. Methods and materials: This study was conducted to detect RSV antigen positivity and the sociodemographic profile of children with RSV antigen positive bronchiolitis. From October 2022 to March 2023, this observational study was conducted in the pediatrics department of Chattogram Medical College Hospital. Ninety-two nasopharyngeal swabs from children younger than two years, were tested for RSV antigen. The mean and standard deviation were used to express the demographic data. Chi-square analysis was used to examine differences in group proportions. Results: RSV antigen positivity was detected in 45.7% of the 92 cases, with a mean age of 4.18±3.08 months. Severe bronchiolitis cases were more common (22.8%) among antigen positive cases and had the longest hospital stay. During the months of November (42.4%) and December (29.3%), RSV infection levels peaked. This study describes that during the seasonal epidemics, RSV was the main concern, as the number of positive cases decreased in the months that followed. The signs and symptoms of RSV positive and negative cases were not significantly different. Conclusion: A simple, low-cost and bedside RSV test can be considered as a valuable diagnostic tool in a low resource setting. J Bangladesh Coll Phys Surg 2024; 42: 368-378

Association between asthma and IgG levels specific for rhinovirus and respiratory syncytial virus antigens in children and adults

BackgroundViral infections in childhood, especially to rhinovirus (RV) and respiratory syncytial virus (RSV) are associated with asthma inception and exacerbation. However, little is known about the role of RV- and RSV-specific antibodies in childhood versus adult asthma. ObjectiveTo investigate associations between RV- and RSV-specific IgG levels with asthma phenotypes, in children and adults. MethodsThe analysis included 1771 samples from 1501 participants of the Epidemiological Study on the Genetics and Environment of Asthma (EGEA) (530 children (mean(sd) age = 11.1 (2.8) and 1241 adults (mean(sd) age = 43.4(16.7), among which 274 and 498 had ever asthma, respectively). RSV- and RV-specific IgG levels were determined using micro-arrayed virus-derived antigens and peptides. Cross-sectional associations between standardized RSV- and RV-specific IgG levels and asthma phenotypes were estimated by multiple regression models. ResultsIn children, ever asthma was associated with higher IgG levels specific to RV, especially to RV-A, RV-C and to RSV (adj-OR for 1-sd increase in IgG levels = 1.52 (95%CI, 1.16;1.99), 1.42 (1.10;1.83) and 1.24 (0.99;1.54), respectively). These associations were stronger for moderate-to-severe asthma than for mild asthma. Conversely in adults, ever asthma was associated with lower RV-A, RV-B and RV-C IgG levels (adjusted OR = 0.86 (0.74;0.99), 0.83 (0.73;0.95) and 0.85 (0.73;0.99), respectively). ConclusionOur results suggest that the association between respiratory virus specific antibody levels and asthma varies during life, with asthma associated with higher levels of IgG to RSV, RV-A and RV-C in children and lower levels of IgG responses to RV-A/B/C in adults.

Analysis of the epidemic characteristics of common respiratory pathogens infection in children in a 3A special hospital

ObjectiveTo analyze the epidemic characteristics of common respiratory tract infection pathogens in children with respiratory tract infection, and provide scientific basis for the prevention and control of respiratory tract infection.MethodsA retrospective collection of clinical data was conducted on 11,538 children with respiratory tract infections at Luoyang Maternal and Child Health Hospital from December 2022 to November 2023. The types of respiratory tract infections, including upper and lower respiratory tract infections, as well as five respiratory pathogens: influenza A virus (influenza A), influenza B virus (influenza B virus, adenovirus (ADV), respiratory syncytial virus (RSV), and Mycoplasma pneumoniae (MP) infections, were analyzed and compared for different genders, ages, temperatures, and air quality in different months; And the changes of five pathogens in children with respiratory tract infections of different disease severity.ResultsFrom December 2022 to November 2023, a total of 11,538 children with respiratory infections were included in the analysis, including 6436 males and 5102 females, with an age of 4.92 ± 2.03 years. The proportion of upper respiratory tract infections is as high as 72.17%, and lower respiratory tract infections account for 27.83%. Among them, 2387 were positive for Flu A antigen, with a positive rate of 20.69%, 51 cases were positive for Flu B antigen, and the positive rate was 0.4%, 1296 cases were positive for adv antigen, with a positive rate of 11.23%, 868 cases were positive for RSV antigen, with a positive rate of 7.52%, 2481 cases were positive for MP IgM antibody or MP antigen, and the positive rate was 21.50%. Flu B in male children The infection rate of ADV and MP was higher than that of female children (p < 0.05); Among children in different age groups, the older the age, the older the Flu A The higher the infection rate of MP (p < 0.05), the higher the positive rate of RSV in children with younger age (p < 0.05). The positive rate of ADV in children aged 3–6 years and > 6 years was higher than that in children aged 0–3 years (p < 0.05); Flu A and MP are popular throughout the year, and the positive rate peaks during the period of temperature rise and air quality decline from February to March, and during the period of temperature drop and air quality index rise from August to November, The positive rate of RSV peaked after the turning point of temperature rise from March to April. The infection rate was higher during the period of sharp decline in air quality from March to May and sharp decline in temperature in November, The positive rate of ADV was higher at the turning point of temperature rise from February to March, and then the infection rate decreased. During the period of sharp temperature drop from August to November, the positive rate increased sharply, and the peak of infection occurred; As the disease worsens, The positive rates of Flu A, Flu B, RSV, MP and combined infection with more than two pathogens were all increased (p < 0.05).ConclusionAfter the new coronavirus epidemic in 2022, Flu A and MP have the highest infection rate of respiratory pathogens in children, showing a peak growth in general, with epidemic characteristics changing with environmental temperature, air quality and seasons. The main disease type is upper respiratory tract infection, MP and adv infections were mainly in male children, Flu A, MP and ADV infections are more common in older children, RSV infection was more common in younger children; Flu A, Flu B, RSV and MP infection and the co infection of more than two pathogens may more easily lead to the occurrence of severe pneumonia.

Analysis of the prevalence and clinical features of respiratory syncytial virus infection in a pediatric hospital in Zhejiang Province from 2019 to 2023.

The aim of this study was to investigate the epidemiological characteristics of respiratory syncytial virus (RSV) infections in children in Zhejiang from 2019 to 2023. Data from pediatric patients who visited the Children's Hospital of Zhejiang University School of Medicine for RSV infection between 2019 and 2023 were analyzed. Nasopharyngeal swabs were collected for RSV antigen detection, and relevant patient information was collected. Factors such as age were analyzed. A total of 673 094 specimens were included from 2019 to 2023, with a rate of positive specimens of 4.74% (31 929/673 094). The highest rate of positive specimens of 10.82%, was recorded in 2021, while the remaining years had a rate of approximately 3%-5%. In terms of seasonal prevalence characteristics, the rate of positive specimens in 2019, 2020, and 2022 peaked in the winter months at approximately 8% and decreased in the summer months, where the rate of positive specimens remained at approximately 0.5%. In contrast, summer is the peak period for RSV incidence in 2021 and 2023, with the rate of positive specimens being as high as 9%-12%. Based on the prevalence characteristics of gender and age, this study found that the detection rate of positive specimens was higher in boys than in girls in 2019-2023. In 2019-2022, among the different age groups, the highest rate of positive specimens was found in children aged 0 to <6 months, and it decreased with age. In 2023, the rate of positive specimens was above 8% in the 0 to <6 months, 6 to <12 months, and 1-2 years age groups, with the highest rate of positive specimens in the 1-2 years age group, and a gradual decrease in the rate of positive specimens with age for children over 3 years of age. Between 2019 and 2023, the epidemiological pattern of RSV changed. A summer peak was observed in 2021 and 2023.

A Highly Sensitive Dual-Drive Microfluidic Device for Multiplexed Detection of Respiratory Virus Antigens.

Conventional microfluidic systems that rely on capillary force have a fixed structure and limited sensitivity, which cannot meet the demands of clinical applications. Herein, we propose a dual-drive microfluidic device for sensitive and flexible detection of multiple pathogenic microorganisms antigens/antibodies. The device comprises a portable microfluidic analyzer and a dual-drive microfluidic chip. Along with capillary force, a second active driving force is provided by a removable self-driving valve in the waste chamber. The interval between these two driving forces can be adjusted to control the reaction time in the microchannel, optimizing the formation of antigen-antibody complexes and enhancing sensitivity. Moreover, the material used in the self-driving valve can be changed to adjust the active force strength needed for different tests. The device offers quantitative analysis for respiratory syncytial virus antigen and SARS-CoV-2 antigen using a 35 μL sample, delivering results within 5 min. The detection limits of the system were 1.121 ng/mL and 0.447 ng/mL for respiratory syncytial virus recombinant fusion protein and SARS-CoV-2 recombinant nucleoprotein, respectively. Although the dual-drive microfluidic device has been used for immunoassay for respiratory syncytial virus and SARS-CoV-2 in this study, it can be easily adapted to other immunoassay applications by changing the critical reagents.

Low-dose M.tb infection but not BCG or MTBVAC vaccination enhances heterologous antibody titres in non-human primates.

Mycobacteria are known to exert a range of heterologous effects on the immune system. The mycobacteria-based Freund's Complete Adjuvant is a potent non-specific stimulator of the immune response used in immunization protocols promoting antibody production, and Mycobacterium bovis Bacille Calmette Guérin (BCG) vaccination has been linked with decreased morbidity and mortality beyond the specific protection it provides against tuberculosis (TB) in some populations and age groups. The role of heterologous antibodies in this phenomenon, if any, remains unclear and under-studied. We set out to evaluate antibody responses to a range of unrelated pathogens following infection with Mycobacterium tuberculosis (M.tb) and vaccination with BCG or a candidate TB vaccine, MTBVAC, in non-human primates. We demonstrate a significant increase in the titer of antibodies against SARS-CoV-2, cytomegalovirus, Epstein-Barr virus, tetanus toxoid, and respiratory syncytial virus antigens following low-dose aerosol infection with M.tb. The magnitude of some of these responses correlated with TB disease severity. However, vaccination with BCG administered by the intradermal, intravenous or aerosol routes, or intradermal delivery of MTBVAC, did not increase antibody responses against unrelated pathogens. Our findings suggest that it is unlikely that heterologous antibodies contribute to the non-specific effects of these vaccines. The apparent dysregulation of B cell responses associated with TB disease warrants further investigation, with potential implications for risk of B cell cancers and novel therapeutic strategies.

Study on transcriptome characteristics of respiratory syncytial virus bronchiolitis in children by RNA sequencing

To explore the biological characteristics related to the pathogenesis and severity of respiratory syncytial virus (RSV) bronchiolitis by RNA sequencing of white blood cells in children with RSV bronchiolitis. This study is a case-control study. A total of 87 children diagnosed with bronchiolitis and RSV antigen positive and/or RSV nucleic acid positive in the pediatric respiratory department of the Second Affiliated Hospital of Wenzhou Medical University from October 2019 to April 2022 were selected as the case group. The case group was divided into three groups based on the condition: mild, moderate, and severe, and there were two groups according to the presence or absence of atopic symptoms: the atopic group and the non-atopic group, forty healthy children in the same period were selected as the control group. The whole blood leukocyte RNA of the children in the case group and the control group was extracted for RNA sequencing, and the data were analyzed to obtain differentially expressed genes (DEGs). Then, the immunobiological pathways and genes related to the pathogenesis, disease condition, and atopy were screened through Gene Ontology (GO) annotation, Kyoto Gene and Genome Encyclopedia (KEGG) annotation, and protein interaction network (PPI) construction methods. Construct the weighted gene co-expression network analysis (WGCNA) module to identify potential biological indicators related to disease severity.Compared with the control group, the case group had a total of 1 782 DEGs, including 1 586 upregulated genes and 196 downregulated genes. The GO pathway enrichment of DEGs is mainly enriched in molecular functions such as peroxidase activity and oxidoreductase activity. In the cytological components, it is mainly enriched in cytoplasmic vesicle lumen and secretory granule lumen. In biological processes, it is mainly enriched in processes such as neutrophil activation involved in immune responses, neutrophil degranulation, and neutrophil activation. KEGG analysis is mainly concentrated in the signal pathway of the viral protein interaction with cytokine and cytokine receptor. A PPI network was constructed to screen four genes at the core position, including CCL2, IL-10, MMP9 and JUN. The DEGs obtained by comparing different disease groups with the control group are mainly enriched in retrograde endocannabinoid signaling and cell apoptosis pathways. WGCNA analysis showed that the brown module related to oxygen saturation was most closely related to the disease, and its gene was mainly enriched in the RNA helicase retinoic acid inducible gene-I (RIG-I) like receptor signal pathway. There are 230 specific DEGs in the atopic group and 444 in the non-atopic group. KEGG enrichment analysis results show that both groups are enriched to NF-κB signaling pathway, the characteristic does not cause significant changes in immune response and transcriptome characteristics in children with RSV bronchiolitis. In conclusion, neutrophil activation, degranulation pathway and signal pathway of interaction between viral protein and cytokine and cytokine receptor are involved in the immune response of RSV bronchiolitis host. CCL2, IL-10, MMP9 and JUN genes may be associated with the pathogenesis. They might be potential biomarkers related to disease severity in RIG-I like receptors, cell apoptosis, and endogenous cannabinoid related signaling pathways.

Comparison of sinonasal symptoms in upper respiratory tract infections during the infectious diseases season of November 2023 to March 2024-a cross-sectional study.

Upper respiratory tract infections (URTIs) are among the most common reasons for patients consulting a general practitioner (GP) during the infectious diseases season, with viruses being the predominant cause. The COVID-19 pandemic has significantly impacted GPs' perception of these infections. The pandemic's progression, especially with the emergence of the Omicron variant, has complicated the diagnosis and treatment of URTIs, with evolving symptoms. The aim of this study was to assess the differences in symptoms reported by patients with various infections, such as COVID-19, influenza, common cold, and post-viral rhinosinusitis, during the infectious diseases season of November 2023 to March 2024. The study was conducted in a primary health care clinic, providing care for a population of approximately 10,000 people, among adult patients presenting with URTI symptoms during the 2023/2024 infectious diseases season. Patients qualified for the study were swabbed for SARS-CoV-2, influenza A and B and respiratory syncytial virus (RSV) antigens. Symptoms were assessed with the use of a semi-structured questionnaire. Of the 1810 patients presenting with symptoms of URTIs, 276 patients were included in the study. Among patients with COVID-19, symptoms of nasal obstruction (p = 0.005) and nasal discharge (p = 0.001) were less common than in those with influenza or common cold. However, these nasal symptoms were significantly more frequent among patients with COVID-19 who had confirmed previous immunization (COVID-19 history or vaccination) (p = 0.028). The incidence of individual sinonasal symptoms varies significantly depending on the aetiological agent of the URTI. This observation may not only help clinicians make the correct diagnosis, but also suggests an inflammatory response in the nasal mucosa and paranasal sinuses that is dependent on the aetiological agent. The study also indicates that this response is altered within the same virus species following immunization. The study's limitations include a small sample size (276 patients), focus on one season and one GP practice, and reliance on clinical signs and antigen tests. Nonetheless, the findings provide valuable insights. Further research with larger patient groups and extended follow-up periods is required to confirm these findings.

New Insights on Respiratory Syncytial Virus Prevention.

Respiratory syncytial virus (RSV) is a well-known infant pathogen transmitted mainly by droplets. It is a leading cause of upper respiratory tract infections in children, usually with a mild course of illness. RSV has also been a threat to older people, especially those with underlying medical conditions. For a long time, prevention was limited to passive immunoprophylaxis with palivizumab for high-risk infants. There was a strong need to find other treatment or prevention methods against RSV infections. In addition, after the coronavirus disease 2019 (COVID-19) pandemic, some significant changes in RSV epidemiology have been observed. Researchers noticed the shift in RSV seasonality and age distribution and the increased number of cases in older infants and adults. All of these made the need to find other medical options even stronger. Fortunately, two protein-based vaccines against RSV have successfully passed all phases of clinical trials and have been approved for use by adults and older people. One of them is also approved for infants from birth to 6 months of age (after maternal immunisation during pregnancy) and for pregnant women between 24 and 36 weeks of pregnancy. Also, a new passive immunisation option named nirsevimab (a highly potent monoclonal antibody with a long half-life) is now available for the paediatric group. In this review, we will discuss the previous and current RSV prevention methods in the light of structural discoveries of RSV antigens.

Immune Profiling of Respiratory Syncytial Virus (RSV) for the Development of Targeted Immunotherapy

Introduction: RSV-associated respiratory viral infections are a major public health problem affecting the immunologically naïve/compromised population. For example, RSV-induced bronchiolitis and pneumonia are the leading cause of hospitalization in infants and young children worldwide, while in adult allogeneic hematopoietic transplant (HCT) recipients the incidence of progression from upper to lower respiratory tract infection (LRTI) is 40-60%, with mortality rates as high as 80%. At the national level, the Fall 2022-Spring 2023 RSV surge translated into a sharp rise in hospitalization rates surpassing last season's respective rate by almost 5-fold (https://www.cdc.gov/rsv/research/rsv-net). Our group has previously demonstrated the feasibility, safety and clinical efficacy of administering allogeneic ex vivo expanded multivirus-specific T cells (multi-VSTs) as a banked, off-the-shelf product for the treatment of EBV, CMV, BKV, HHV6, AdV and SARS-CoV-2 infections/disease in immunocompromised individuals. Given the RSV-associated morbidity and the paucity of therapeutic agents, we sought to characterize the cellular immune responses to RSV with a view to developing a targeted T-cell therapy product for those at highest risk of severe disease (i.e. HCT recipients, elderly/immunocompromised patients). Methods: To first identify immunogenic and protective RSV antigens we exposed PBMCs from healthy adult donors to pepmixes (overlapping peptide libraries) spanning the 11 RSV-encoded antigens and found that 7 induced highly reactive T cells. However, Nucleoprotein (N) and Fusion Protein (F) proved to be immunogenic in all donors and were thus advanced for VST manufacturing. We subsequently utilized our optimized VST manufacturing process and culture in a G-Rex device in medium supplemented with activating cytokines to generate RSV-specific VSTs (RSV-STs) with activity against this combination of immunodominant targets. Results: We achieved a mean 5.2±1-fold expansion (mean±SEM; n=13) of cells that were comprised almost exclusively of CD3+ T cells (94.08±1.15%), with a mixture of cytotoxic (CD8+; 28.91±5.16%) and helper (CD4+; 71.09±5.15%) T cells. These cells had a phenotype consistent with effector function and memory potential, as evidenced by upregulation of the activation markers CD25, CD69, and CD28 and expression of central (CD45RO+/CD62L+) and effector memory markers (CD45RO+/CD62L-) with minimal expression of exhaustion-related markers such as PD1, Tim3 and LAG3. The anti-viral activity of the expanded cells was confirmed in an IFNγ ELISpot using both stimulating antigens as an immunogen and all lines proved to be reactive against the target antigens (N: 3587±939 SFC/2x10 5; F: 3526±743). As demonstrated by surface and intracellular flow cytometry, the immune response was mediated by both CD4+ and CD8+ T cell subsets through IFNγ/TNFα production and upregulation of activation/costimulatory markers. Reactive cells were polyfunctional and primarily Th1-polarized as evidenced by IFNγ, Granzyme-B, IL-2 and GM-CSF production measured by FluoroSpot and Luminex array. Finally, the expanded cells were able to kill viral pepmix-loaded autologous PHA blasts with minimal/no activity against non-antigen-expressing autologous and allogeneic targets. Conclusion: Healthy donor-derived RSV-STs are Th1-polarized, polyfunctional and selectively able to kill viral antigen-expressing targets with no auto- or alloreactivity, indicative of their safety for clinical use. A clinical trial evaluating their safety and activity in HCT recipients as part of an off-the-shelf multi-respiratory virus-directed product is currently underway (NCT04933968, https://clinicaltrials.gov).

CpG ODN enhances the efficacy of F protein vaccine against respiratory syncytial virus infection in the upper respiratory tract via CD4+ T cells

Respiratory syncytial virus (RSV) is a leading cause of severe respiratory illness worldwide, particularly in infants and older adults. Vaccines targeting the fusion glycoprotein (F protein) —one of the surface antigens of RSV— are highly effective in preventing RSV-associated severe lower respiratory tract disease. However, the efficacy of these vaccines against upper respiratory tract challenge needs improvement. Here, we aimed to examine the efficacy of F protein vaccines with or without CpG oligodeoxynucleotide (CpG ODN) as an adjuvant in the upper and lower respiratory tracts in mice. F + CpG ODN induced higher levels of F-specific IgG than that induced by F alone; however, levels of neutralizing antibodies did not increase compared to those induced by F alone. F + CpG ODN induced T helper 1 (Th1) cells while F alone induced T helper 2 (Th2) cells. Moreover, F + CpG ODN improved the protection against RSV challenge in the upper respiratory tract compared to F alone, which was largely dependent on CD4+ T cells. Meanwhile, both F + CpG ODN and F alone protected the lower respiratory tract. In conclusion, we demonstrated that induction of F-specific Th1 cells is an effective strategy to prevent RSV challenge in the upper respiratory tract in F protein vaccines. These data support the development of novel F protein vaccines.

A-302 Agreement Assessment Between Molecular and Rapid Tests in Respiratory Viruses Detection

Abstract Background Diseases caused by respiratory viruses are the most frequent diseases in humans and have a significant impact on morbidity and mortality worldwide. Due to their transmission nature, these viruses are able to widespread dissemination. The pandemic caused by COVID-19 highlights this potential, however, other respiratory viruses also continue to circulate such as Respiratory Syncytial Virus (RSV) and Influenza (FLU). Efficient diagnostic tools are necessary, especially in endemic regions. Although molecular tests are gold standards, rapid tests (RTs) represent a great alternative once they are more accessible, faster, easier to manage, and can be performed at the point of care. Therefore, this work aimed to evaluate the analytical performance of RTs compared to molecular tests in the detection of viral antigens of RSV or FLU in swab samples. Methods Swab samples in saline solution (n = 60) were tested by qPCR molecular assay Multiplex Alinity m Resp-4-Plex Assay (Abbott Molecular) and RTs immunofluorescence-based (ECO-F RSV ag and ECO-F Influenza A/B—ECO Diagnostica). For the molecular assay, samples were prepared according to the manufacturer's instructions. For RTs, samples were submitted to the extraction buffer, incubated for 10 or 15 minutes respectively, and analyzed by ECO Reader F200 equipment, according to the manufacturer's instructions. It uses a cut-off value ≥1.00 for positive samples and &amp;lt;1.00 for negative samples. Results All negative samples (RSV = 20; FLU = 20) in molecular test were concordant with RTs results. The number of positive samples detected by molecular test was 4 and 16 for FLU and RSV respectively, while RTs detected a lower number of positive samples (FLU = 2; RSV = 10). Both RTs achieved a specificity of 100%; sensibility was 62, 50% for RSV and 50% for FLU. Using Cohen's Kappa index to assess the agreement between the compared tests, it was obtained the expected and observed values of 0.83 and 0.53 for RSV and 0.92 and 0.78 for FLU, which represents an index of 0.649 and 0.625 respectively. These results indicate substantial agreement between the tests, although the sensitivity of the molecular assay was superior. Conclusion Molecular tests can be used to confirm the results of RTs, once they are the gold standard for diagnosis. However, they have a high operational cost, which makes RTs a good alternative to help in the screening of these respiratory diseases, especially in resource-limited settings, allowing effective treatment and management for the patient.

New Generation of Systemic Inflammatory Markers for Respiratory Syncytial Virus Infection in Children.

This study evaluated the relationship between the systemic immune-inflammatory index (SII), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) with clinical findings of respiratory syncytial virus (RSV) infection among children with a diagnosis of lower respiratory tract infection (LRTI). The study was conducted between 1 January 2020 and 1 January 2022 in a pediatric clinic. This retrospective study included 286 consecutive patients between 0 and 12 years of age, 138 of whom were RSV (+) (48.25%) and 148 of whom were RSV (-) (51.75%). The detection of the RSV antigen was carried out using the chromatographic immunoassay method on nasopharyngeal swabbing samples. CRP content was significantly higher in patients with RSV (+) than in children with RSV (-), while NLR, PLR, and SII, as inflammatory parameters, were significantly lower. Fever, coughs, and wheezing were the most common symptoms in the RSV (+) groups (100%). RSV infections were the highest in November, October, and December, in that order. The AUC was statistically significant for parameters in all groups. AUC values were 0.841 (95%: 0.765-0.917) for leukocytes, 0.703 (95%: 0.618-0.788) for lymphocytes, 0.869 (95%: 0.800-0.937) for CRP, 0.706 (95%: 0.636-0.776) for NLR, 0.779 (95%: 0.722-0.836) for PLR, and 0.705 (95%: 0.633-0.776) for SII. CRP was found to have both high sensitivity (80.4%) and high specificity (82.4%) among all parameters. While the ROC analysis results showed similar results for children under two years old, only CRP and NLR were statistically significant in this group. CRP performed better than other blood parameters as a marker. The NLR, PLR, and SII index were significantly lower in LRTI patients with RSV (+) than in those with RSV (-), which implies a higher grade of inflammation. If the cause of the disease can be determined by this method, disease management will be easier, and unnecessary antibiotics could be avoided.

Immunoinformatics aided approach for predicting potent cytotoxic T cell epitopes of respiratory syncytial virus

Respiratory syncytial virus (RSV) is an infectious viral pathogen that causing serious respiratory infection in adults and neonates. The only approved therapies for RSV are the monoclonal antibodies palivizumab and its derivative motavizumab. Both treatments are expensive and require a hospital setting for administration. A vaccine represents a safe, effective and cheaper alternative for preventing RSV infection. In silico prediction methods have proven to be valuable in speeding up the process of vaccine design. In this study, reverse vaccinology methods were used to predict the cytotoxic T lymphocytes (CTL) epitopes from the entire proteome of RSV strain A. From amongst 3402 predicted binders to 12 high frequency alleles from the Immune Epitope Database (IEDB), 567 had positive processing scores while 327 epitopes were predicted to be immunogenic. A thorough examination of the 327 epitopes for possible antigenicity, allergenicity and toxicity resulted in 95 epitopes with desirable properties. A BLASTp analysis revealed 94 unique and non-homologous epitopes that were subjected to molecular docking across the 12 high frequency alleles. The final dataset of 70 epitopes contained 13 experimentally proven and 57 unique epitopes from a total of 11 RSV proteins. From our findings on selected T-cell-specific RSV antigen epitopes, notably the four epitopes confirmed to exhibit stable binding by molecular dynamics. The prediction pipeline used in this study represents an effective way to screen the immunogenic epitopes from other pathogens. Communicated by Ramaswamy H. Sarma

The Quest for a Respiratory Syncytial Virus Vaccine for Older Adults: Thinking beyond the F Protein.

Respiratory syncytial virus (RSV) is a common cause of paediatric respiratory tract infection and causes a significant health burden in older adults. Natural immunity to RSV is incomplete, permitting recurrent symptomatic infection over an individual's lifespan. When combined with immunosenescence, this increases older adults' susceptibility to more severe disease symptoms. As RSV prophylaxis is currently limited to infants, older adults represent an important target population for RSV vaccine development. The relationship between RSV and our immune systems is complex, and these interactions require deeper understanding to tailor an effective vaccine candidate towards older adults. To date, vaccine candidates targeting RSV antigens, including pre-F, F, G (A), G (B), M2-1, and N, have shown efficacy against RSV infection in older adults in clinical trial settings. Although vaccine candidates have demonstrated robust neutralising IgG and cellular responses, it is important that research continues to investigate the RSV immune response in order to further understand how the choice of antigenic target site may impact vaccine effectiveness. In this article, we discuss the Phase 3 vaccine candidates being tested in older adults and review the hurdles that must be overcome to achieve effective protection against RSV.

Platelet to Lymphocyte Ratıo in Respıratory Syncytıal Vırus Infectıon

Introduction: We aim to examine the role of Platelet to lymphocyte ratio (PLR) and Platelet to Lymphocyte and monocyte ratio (PLT/LY+MO) values in Respiratory Syncytial Virus (RSV) infection. Methodology: Complete blood counts and RSV Antigen test results of 76 patients, between the age of 0-12 were investigated retrospectively. PLR values are calculated using Platelet Count / Lymphocyte Count formula, whereas PLMR values are calculated using Platelet Count / Lymphocyte Count + Monocyte Count. Results: Out of 76, 32 patients were diagnosed as RSV infected. Lymphocyte and monocyte percentage and platelet count were significantly higher in RSV positive group. Monocyte percentage in lower respiratory tract RSV infection was significantly lower compared to upper respiratory tract RSV infection. Conclusions: Our study revealed that these blood parameters may be an important clue for the clinician for RSV infection and also play a role as a guide before advanced techniques.

Immunity Cell Responses to RSV and the Role of Antiviral Inhibitors: A Systematic Review.

Antigen-presenting cells recognize respiratory syncytial virus antigens, and produce cytokines and chemokines that act on immune cells. Dendritic cells play the main role in inflammatory cytokine responses. Similarly, alveolar macrophages produce IFN-β, IFN-α, TNF-α, IL-6, CXCL10, and CCL3, while alternatively activated macrophages differentiate at the late phase, and require IL-13 or IL-4 cytokines. Furthermore, activated NKT cells secrete IL-13 and IL-4 that cause lung epithelial, endothelial and fibroblasts to secrete eotaxin that enhances the recruitment of eosinophil to the lung. CD8+ and CD4+T cells infection by the virus decreases the IFN-γ and IL-2 production. Despite this, both are involved in terminating virus replication. CD8+T cells produce a larger amount of IFN-γ than CD4+T cells, and CD8+T cells activated under type 2 conditions produce IL-4, down regulating CD8 expression, granzyme and IFN-γ production. Antiviral inhibitors inhibit biological functions of viral proteins. Some of them directly target the virus replication machinery and are effective at later stages of infection; while others inhibit F protein dependent fusion and syncytium formation. TMC353121 reduces inflammatory cytokines, TNF-α, IL-6, and IL-1β and chemokines, KC, IP-10, MCP and MIP1-α. EDP-938 inhibits viral nucleoprotein (N), while GRP-156784 blocks the activity of respiratory syncytial virus ribonucleic acid (RNA) polymerase. PC786 inhibits non-structural protein 1 (NS-1) gene, RANTES transcripts, virus-induced CCL5, IL-6, and mucin increase. In general, it is an immune reaction that is blamed for the disease severity and pathogenesis in respiratory syncytial virus infection. Anti-viral inhibitors not only inhibit viral entry and replication, but also may reduce inflammatory cytokines and chemokines. Many respiratory syncytial virus inhibitors are proposed; however, only palivizumab and ribavirin are approved for prophylaxis and treatment, respectively. Hence, this review is focused on immunity cell responses to respiratory syncytial virus and the role of antiviral inhibitors.

The Scope of Respiratory Syncytial Virus Infection in a Tertiary Hospital in the Eastern Province of Saudi Arabia and the Change in Seasonal Pattern during and after the COVID-19 Pandemic.

Background and Objectives: Respiratory syncytial virus (RSV) is a major cause of morbidity and hospital admission due to respiratory tract infection among infants and young children. The current study aims to describe the prevalence and the seasonal pattern of RSV during the previous seven years. Materials and Methods: Clinical data and RSV antigen and PCR test results were collected from patients' medical records at King Fahd Hospital of the University in the Eastern Province of Saudi Arabia between January 2015 and February 2022. Results: The overall percentage of RSV detection was 26.3% (336/1279) among the tested individuals. RSV infection was more common among children below five years and elderly above 60 years of age. Two-thirds of the cases required hospitalization. The average hospital stay due to RSV infection was 6.5 days (range 0-56 days). The rate of hospitalization was higher among infants and younger children and decreased with age (p-value &lt; 0.001). RSV infection was more prevalent between August and February and decreased appreciably between March and July. The peak level of infection was during December and January. No RSV infections were reported during the COVID-19 pandemic and the following winter. The cases increased again in August 2021, with an unusual out-of-season peak. Conclusions: RSV infection is one of the important causes of morbidity and hospitalization among infants and young children in Saudi Arabia. The seasonal pattern of infection has changed after the COVID-19 pandemic, and the physicians should be aware that infection may happen currently at different times throughout the year.

Prior respiratory syncytial virus infection reduces vaccine-mediated Th2-skewed immunity, but retains enhanced RSV F-specific CD8 T cell responses elicited by a Th1-skewing vaccine formulation.

Respiratory syncytial virus (RSV) remains the most common cause of lower respiratory tract infections in children worldwide. Development of a vaccine has been hindered due the risk of enhanced respiratory disease (ERD) following natural RSV exposure and the young age (<6 months) at which children would require protection. Risk factors linked to the development of ERD include poorly neutralizing antibody, seronegative status (never been exposed to RSV), and a Th2-type immune response. Stabilization of the more antigenic prefusion F protein (PreF) has reinvigorated hope for a protective RSV vaccine that elicits potent neutralizing antibody. While anecdotal evidence suggests that children and adults previously exposed to RSV (seropositive) are not at risk for developing vaccine associated ERD, differences in host immune responses in seropositive and seronegative individuals that may protect against ERD remain unclear. It is also unclear if vaccine formulations that skew towards Th1- versus Th2-type immune responses increase pathology or provide greater protection in seropositive individuals. Therefore, the goal of this work was to compare the host immune response to a stabilized prefusion RSV antigen formulated alone or with Th1 or Th2 skewing adjuvants in seronegative and seropositive BALB/c mice. We have developed a novel BALB/c mouse model whereby mice are first infected with RSV (seropositive) and then vaccinated during pregnancy to recapitulate maternal immunization strategies. Results of these studies show that prior RSV infection mitigates vaccine-mediated skewing by Th1- and Th2-polarizing adjuvants that was observed in seronegative animals. Moreover, vaccination with PreF plus the Th1-skewing adjuvant, Advax, increased RSV F85-93-specific CD8 T cells in both seronegative and seropositive dams. These data demonstrate the importance of utilizing seropositive animals in preclinical vaccine studies to assess both the safety and efficacy of candidate RSV vaccines.

Virus-like particles coexpressing the PreF and Gt antigens of respiratory syncytial virus confer protection in mice.

Aims: The purpose of this study was to assess the protective efficacy of virus-like particles (VLPs) co-expressing the pre-fusogenic (PreF) and G proteinwith tandem repeats (Gt) antigens of respiratory syncytial virus (RSV) in mice. Materials & methods: VLP constructs expressing PreF, Gt or both were used to immunize mice, and the protective efficacies were evaluated using antibody responses, neutralizing antibody titers, T-cell responses, histopathological assessment and plaque assay. Results: PreF+Gt VLP immunization elicited strong RSV-specific antibody responses and pulmonary T-cell responses that contributed to lessening virus titer and inflammation. Conclusion: Our findings suggest that coexpressing PreF and Gt antigens elicits better protection than either one alone. This combinatorial approach could assist in future RSV vaccine development.