The Burden and Long-term Respiratory Morbidity Associated with Respiratory Syncytial Virus Infection in Early Childhood

Improving Care for People with Chronic Respiratory Diseases: Taking a Policy Lens

Chronic respiratory diseases (CRDs) affect almost 470 million people worldwide, and this number is growing. CRDs take a significant toll on the capacity of health systems and economies, and their effect on people's lives can be devastating. Despite high rates of prevalence and mortality, CRDs are underprioritised by policymakers and governments. Tackling these conditions will require a holistic, multisectoral approach, including government-led strategies for prevention, diagnosis, management and investment in research. In this article, we provide a clear rationale for prioritising CRDs to advance population health. Proactive steps in countries of all income levels must be taken promptly to limit the growing prevalence and impact of CRDs both now and in the future.

Efficacy and safety of ziresovir in hospitalised infants aged 6 months or younger with respiratory syncytial virus infection in China: findings from a phase 3 randomised trial with 24-month follow-up

BACKGROUND

Respiratory syncytial virus (RSV) is a particularly dangerous infection in some populations, including very young infants. This study examined the efficacy and safety of ziresovir in hospitalised infants aged 6 months or younger with RSV infection.

METHODS

In this double-blind, randomised, placebo-controlled trial conducted across 28 hospitals in China, patients aged 1-24 months hospitalised for virologically confirmed RSV infection were randomly allocated (2:1) to receive ziresovir (10-40 mg by weight twice daily) or placebo orally for 5 days, with 2 years of follow-up. Patients were included if they had a Wang bronchiolitis clinical score (WBCS) of at least 5 at first dosing and were administered their first dose of study drug within 7 days of the onset of symptoms of RSV infection. In this prespecified subanalysis of patients aged 6 months and younger at randomisation, we analysed the primary endpoint (change from baseline in WBCS on day 3 [48 h post-baseline]) in the intention-to-treat infected (ITT-i) population (comprising patients who received at least one dose of study drug and who had PCR-confirmed RSV infection). Safety endpoints were assessed in all patients who received at least one dose. This study is registered with ClinicalTrials.gov (NCT04231968) and is completed.

FINDINGS

Participants were recruited from Sept 22, 2020, to Jan 19, 2022, and followed up to Feb 4, 2024. Among patients aged 6 months or younger, 188 participants (125 in the ziresovir group and 63 in the placebo group) received at least one dose of study drug and were included in the safety analysis, while the ITT-i population included 150 patients (100 in the ziresovir group and 50 in the placebo group). In the ziresovir group, 33 (26%) of 125 patients were female, 92 (74%) were male, mean age was 3·4 months (SD 1·4), and mean baseline WBCS was 6·8 (SD 1·7). In the placebo group, 15 (24%) of 63 patients were female, 48 (76%) were male, mean age was 3·3 months (1·5), and mean baseline WBCS was 6·9 (1·8). The least-squares mean change in WBCS from baseline to day 3 was -3·5 points (95% CI -3·9 to -3·1) with ziresovir versus -2·2 points (-2·8 to -1·7) with placebo (difference -1·2 [95% CI -1·9 to -0·6], p=0·0004). Drug-related treatment-emergent adverse events occurred in 22 (18%) of 125 patients who received ziresovir and seven (11%) of 63 patients who received placebo. No drug-related serious adverse events were observed and no deaths occurred.

INTERPRETATION

Ziresovir had a favourable safety profile and was associated with a significant clinical benefit during the treatment period compared with placebo in patients aged 6 months or younger.

FUNDING

Shanghai Ark Biopharmaceutical, National Clinical Research Center for Respiratory Diseases, and National Major Science and Technology Projects of China.

Using machine learning involving diagnoses and medications as a risk prediction tool for post-acute sequelae of COVID-19 (PASC) in primary care

BACKGROUND

The aim of our study was to determine whether the application of machine learning could predict PASC by using diagnoses from primary care and prescribed medication 1 year prior to PASC diagnosis.

METHODS

This population-based case-control study included subjects aged 18-65 years from Sweden. Stochastic gradient boosting was used to develop a predictive model using diagnoses received in primary care, hospitalization due to acute COVID- 19, and prescribed medication. The variables with normalized relative influence (NRI) ≥ 1% showed were considered predictive. Odds ratios of marginal effects (ORME) were calculated.

RESULTS

The study included 47,568 PASC cases and controls. More females (n = 5113) than males (n = 2815) were diagnosed with PASC. Key predictive factors identified in both sexes included prior hospitalization due to acute COVID- 19 (NRI 16.1%, ORME 18.8 for females; NRI 41.7%, ORME 31.6 for males), malaise and fatigue (NRI 14.5%, ORME 4.6 for females; NRI 11.5%, ORME 7.9 for males), and post-viral and related fatigue syndromes (NRI 10.1%, ORME 21.1 for females; NRI 6.4%, ORME 28.4 for males).

CONCLUSIONS

Machine learning can predict PASC based on previous diagnoses and medications. Use of this AI method could support diagnostics of PASC in primary care and provide insight into PASC etiology.

Metabolomic studies of respiratory infections in early life: A narrative review

Respiratory infections are a leading cause of morbidity and mortality during the early life period, and experiencing recurrent infections may increase the risk of developing chronic respiratory diseases, such as asthma. Over the last several decades, metabolomics methods have been applied to inform upon the underlying biochemistry of pediatric respiratory infection response, to discriminate between respiratory infection types, and to identify biomarkers of severity and susceptibility. While these studies have demonstrated the power of applying metabolomics to the study of pediatric respiratory infection and contributed to an understanding of respiratory infections during the unique period of immune development, key differences in study design, infection type(s) of interest, biosamples, metabolomics measurement methods, and lack of external validation have limited the translation of these findings into the clinic. The purpose of this review is to summarize overlaps across existing studies of commonly reported metabolomics findings and emphasize areas of opportunity for future study. We highlight several metabolomics pathways-such as the citric acid cycle and sphingolipid metabolism-that have been reported consistently in respiratory infection response. We then discuss putatively identified metabolomic markers to discriminate between respiratory infection types and possible markers of infection severity and proneness. Finally, we close with a summary and perspective of future directions of the field.

Twenty-five years of palivizumab: a global historic review of its impact on the burden of respiratory syncytial virus disease in children

INTRODUCTION

Respiratory syncytial virus (RSV) causes significant morbidity and mortality in young children. For 25 years, palivizumab has been the only effective pharmaceutical RSV preventive.

AREAS COVERED

We summarize the development and a quarter-century of real-world evidence with palivizumab. We highlight its positive impact on the burden of RSV in high-risk children. Based on lessons learnt from its implementation, we suggest strategies for effective and equitable deployment of newer RSV preventives.

EXPERT OPINION

Following failure of the formalin-inactivated RSV vaccine in 1967, RSV intravenous immunoglobulin was approved in 1996 after three decades' research. Subsequently, palivizumab emerged as the most effective and safe RSV preventive, demonstrated by the IMpact trial, and was licensed in 1998 in the United States. Over the last 25 years, the benefits of palivizumab have been firmly established through a wealth of evidence, predominantly from high-income countries (HICs). To achieve a global impact with the newer RSV preventives, evidenced-based universal guidelines must be developed and endorsed by regulatory authorities and relevant scientific societies. Independent economic evaluations should incorporate all RSV-associated healthcare costs, reduction of long-term respiratory sequelae, and standardized outcomes. Most importantly, equity in product availability and implementation, particularly in low- and middle-income countries (LMICs) is essential.

Cost-Effectiveness and Public Health Impact of Universal Prophylaxis with Nirsevimab Against Respiratory Syncytial Virus (RSV) Infections in all Infants in Japan

INTRODUCTION

Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract disease, and the standard prevention strategy in Japan is limited to high-risk infants. Nirsevimab provides protection against medically attended (MA) RSV infection in healthy late-preterm and term infants and was approved in Japan in 2024. This study estimates the cost-effectiveness of universal immunization with nirsevimab in an all-infant population from the Japanese public healthcare payer perspective.

METHODS

A static decision analytic model, able to track costs and health outcomes in a cohort of infants, was adapted to the Japanese setting. The standard of care, palivizumab, administered to high-risk infants, was compared with nirsevimab administrated to all infants in the first year, and an additional increased dose of nirsevimab (200 mg) in the second season for high-risk infants. Differences in costs and quality-adjusted life years (QALYs) were captured considering RSV-related MA health events requiring inpatient hospitalizations, emergency room visits, and primary care visits, as well as RSV-related complications. Sensitivity and scenario analyses were conducted to explore the robustness and uncertainty of the study.

RESULTS

Assuming a price of ¥45,000 for nirsevimab, universal immunization with nirsevimab was found to be cost-effective with an incremental cost-effectiveness ratio (ICER) of ¥4,537,256/QALY. At the Japanese willingness-to-pay threshold of ¥5,000,000, the economically justifiable price was ¥45,496. Using the societal perspective, the ICER decreased to ¥1,695,635/QALY. Nirsevimab has a substantial public health impact on RSV disease burden, reducing approximately 50% of RSV-associated health events in an all-infant population.

CONCLUSION

The analysis demonstrated that universal prophylaxis strategy with nirsevimab would significantly reduce the health and economic burden associated with RSV among infants in Japan. At the assumed price, nirsevimab can provide a cost-effective prophylaxis option against RSV infection in an all-infant population not limited to infants born prematurely or with high risk.

SMARCA4 regulates inducible BRD4 genomic redistribution coupling intrinsic immunity and plasticity in epithelial injury-repair

Coordinated expression of differentiation and innate pathways is essential for successful mucosal injury-repair. Previously, we discovered that the core SWI/SNF complex ATPase, SWI/SNF-related, matrix associated, actin dependent regulator of chromatin, subfamily A, member 4 (SMARCA4)/Brg1, maintains tumor protein 63 + basal progenitor cells in an epithelial-committed state. In response to viral injury, SMARCA4 complexes BRD4 to activate innate inflammation and promote mesenchymal transition/plasticity. To investigate how innate inflammation couples with plasticity, Cleavage Under Targets and Release Using Nuclease of BRD4 binding was applied to wild type and SMARCA4 knockdown (KD) in mock- or respiratory syncytial virus (RSV)-infected basal cells. In mock-infected cells, BRD4 binds 4017 high-confidence peaks within gene bodies controlling mesenchymal transition pathways. By contrast, RSV replication repositions 2339 BRD4 peaks to open chromatin regions upstream of the genes controlling inducible cytokine, cell adherence, and antiviral programs. Also, we note RSV redistributes BRD4 into super enhancers regulating immune response-associated long noncoding (lnc)RNAs. In SMARCA4 KD cells, BRD4 distribution is reduced on 739 peaks after RSV infection. The boundaries of nucleosome-free regions are reduced by SMARCA4 KD, suggesting its role in maintaining open chromatin of super enhancers. Specifically, SMARCA4-BRD4 enhancer controls lncRNAs important in interferon response factor 1 autoregulation. These data indicate how SWI/SNF ATPases couple BRD4 to lncRNA expression controlling cell state and intrinsic immunity in epithelial injury-repair.

Management of RSV Bronchiolitis in Outpatient Setting

Seasonal respiratory syncytial virus (RSV) lower respiratory infections (RSV-LRI) and bronchiolitis in children remain a high burden to medical facilities. Studies evaluating the practical approach in outpatient settings are scarce. We conducted a survey to provide an insight into management in pediatric offices in Germany. Invitations for participation in an online survey were sent to 623 providers of pediatric primary care via email. Recipients were randomly chosen from national databanks based on zip codes. The response rate was 16,2%, n=92 (14,7%) questionnaires were fully answered and analyzed. 93,5% (n=86) are board certified pediatricians. In outpatient setting, every second patient with suspected or confirmed RSV-LRI is presented three times or more. 40,7% of our participants refer less than 10% of all patients to hospital, 83,7% refer less than one third (<30%). 33,7% of all participants never perform virological testing in suspected cases of RSV-LRI. More than 50% of all participants prescribe bronchodilators, hypertonic saline inhalation is prescribed by 17,4%. Antibiotics are prescribed in less than 10% of all cases of RSV-LRI. About 3/4 ask for a clearer, more conclusive guideline regarding prophylaxis. The diagnostic approach varies significantly. Although not recommended in international guidelines, bronchodilators are still frequently used. Considering emerging options for passive immunization, broader inclusion criteria into immunization regimes are requested by the participants. More conclusive guidelines and recommendations could further improve the management of outpatient RSV-LRI in children.

Surfactant Protein-A and its immunomodulatory roles in infant respiratory syncytial virus infection: a potential for therapeutic intervention?

The vast majority of early-life hospital admissions globally highlight respiratory syncytial virus (RSV), the leading cause of neonatal lower respiratory tract infections, as the major culprit behind the poor neonatal outcomes following respiratory infections. Unlike those of older children and adults, the immune system of neonates looks rather unique, therefore mostly counting on the innate immune system and antibodies of maternal origins. The collaborations between cells and immune compartments during infancy inclines bias toward a T-helper 2 (Th2) immune profile and thereby away from a T-helper 1 (Th1) immune response. What makes it more problematic is that RSV infection also tends to elicit a stronger Th2-biased immune response and drive an aberrant allergy-like inflammation. It is thus evident how RSV infections potentially pave the way for wheezing recurrences and childhood asthma later in life. Surfactant, the essential lung substance for normal breathing processes in mammals, has immunomodulatory properties including lung collectins such as Surfactant Protein-A (SP-A), which is the most abundant protein component of surfactant, and also Surfactant Protein-D (SP-D). Deficiency of SP-A and SP-D has been found to be associated with impaired pathogen clearance and exacerbated immune responses during infections. We therefore conducted a review of the literature to describe pathomechanisms of RSV infections during blunted neonatal immunity potentially facilitating allergy-like inflammatory events within the developing lungs and highlight the potential protective role of the humoral collectin SP-A to mitigate these in the "early in life" pulmonary immune system.

Economic and clinical burden associated with respiratory syncytial virus and impact of universal immunization with nirsevimab in Italy

Objectives

To describe the seasonal respiratory syncytial virus (RSV) burden in Italy considering the current prophylaxis strategy with palivizumab recommended only for high-risk infants (representing only 4.4% of an estimated birth cohort) and to evaluate the potential benefits of a new prophylaxis strategy targeting all infants with nirsevimab.

Methods

A static decision analytic model previously used in the US was adapted to evaluate the RSV-related health and cost outcomes associated with nirsevimab versus standard of care (SoC) for the prevention of RSV medically attended lower respiratory tract infections (RSV-MA-LRTIs). Monthly probabilities of RSV infections, health events, mortality, and complications associated with RSV infections were obtained from the literature. Costs associated with each event were obtained using the available literature and through real-world data analysis of National Hospital Discharge Records.

Results

For one RSV season, in the current SoC, the model estimated 216,100 RSV-MA-LRTIs, 15,121 associated complications, and 16 RSV-deaths-corresponding to an economic burden of approximately €50.5 million related to RSV-MA-LRTIs management, €10.9 million associated with potential complications due to RSV and €3 million in lost productivity due to RSV-deaths. Nirsevimab is expected to prevent 100,208 RSV-MA-LRTIs, 6,969 complications, and 6 deaths due to RSV infections, corresponding to an economic saving of about €23.3, €5, and €1.2 million, respectively.

Conclusion

Nirsevimab is a new prophylaxis strategy that helps to protect all infants against RSV disease and could substantially reduce the clinical and economic burden of RSV in Italy in infants experiencing their first RSV season.

The Impact of Palivizumab for Respiratory Syncytial Virus Prophylaxis on Preschool Childhood Asthma

BACKGROUND

The respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections in infants and is associated with an increased risk of asthma development. Palivizumab, an RSV prophylactic, reduces RSV-related hospitalizations in high-risk infants, but its impact on long-term asthma outcomes remains unclear. This study compares asthma-related healthcare utilization in preschool children born prematurely between those who received Palivizumab (the Prophylaxis (+) group) and those who did not (the Prophylaxis (-) group).

METHODS

This nationwide, population-based retrospective cohort study utilized data from Clalit Healthcare Services in Israel. The study included children born between 32 + 6 and 34 + 6 weeks of gestational age from 2011 to 2018. Descriptive analysis, univariate analysis, and multivariate logistic regression were performed to compare the Prophylaxis (+) and the Prophylaxis (-) groups.

RESULTS

In total, 4503 children were included, with 3287 in the Prophylaxis (+) group and 1216 in the Prophylaxis (-) group. Palivizumab administration was associated with reduced hospitalizations for RSV bronchiolitis (1.8% vs. 3.3%, p = 0.003). However, no significant differences were observed in multivariate analysis for long-term asthma outcomes, including asthma diagnosis (OR = 1.04, CI = 0.84-1.30, p = 0.7) or emergency department visits for asthma (OR = 0.79, CI = 0.54-1.17, p = 0.2). Similarly, Palivizumab administration was not associated with the purchase of short-acting beta-agonists (OR = 1.14, 95% CI 0.98-1.32, p = 0.084), inhaled corticosteroids (OR = 1.1, CI = 0.93-1.32, p = 0.3), or oral corticosteroids (OR = 1.09, CI = 0.94-1.26, p = 0.3).

CONCLUSIONS

While Palivizumab effectively reduces RSV acute bronchiolitis in preterm infants, it does not significantly impact long-term preschool asthma-related healthcare utilization.

Respiratory Syncytial Virus in Pregnancy: An Obstetrics View

Respiratory syncytial virus (RSV) represents one of the most prevalent causes of lower respiratory tract infection in newborns and children by the time they are two years old, with a peak rate of hospitalization in those between two and three months of age and a high risk of morbidity and mortality, especially under the age of six months of life [...].

Early-life respiratory syncytial virus disease and long-term respiratory health

Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infection (LRTI), hospital admission, and mortality in children worldwide. Early-life RSV LRTI has also been associated with subsequent long-term respiratory sequelae, including recurrent LRTI, recurrent wheezing, asthma, and lung function impairment, and these effects can persist into adulthood as chronic respiratory disease. New preventive measures (maternal vaccine or long-acting monoclonal antibodies) have been licensed to reduce the burden of acute RSV LRTI in infants and children at high risk through passive immunisation. Studies of these RSV prevention products show high efficacy and effectiveness, particularly for preventing severe RSV LRTI, with implementation in many high-income countries, but limited access in low-income and middle-income countries (LMICs). These interventions might also reduce the risk of additional health outcomes and long-term morbidity. This Series paper provides the evidence for the long-term effects of early-life RSV disease, discusses mechanisms of disease development, and addresses the potential full public health value of prevention of RSV illness. Further research is needed to determine whether prevention of RSV LRTI or delay of RSV illness in early life might prevent or ameliorate the development of associated long-term respiratory disease. This potential further underscores the urgency for access and availability of new interventions to prevent early-life RSV LRTI in LMICs.

A Phase 1/2a Study Evaluating Safety and Immunogenicity of Ad26.RSV.preF in RSV-seronegative Toddlers Aged 12-24 Months

Background

Respiratory syncytial virus (RSV) causes serious illness in children. The Ad26.RSV.preF vaccine candidate was immunogenic with acceptable safety in a phase 1/2a study of RSV-seropositive children. Here, we assessed its safety and immunogenicity in RSV-seronegative children.

Methods

In this randomized, observer-blinded, placebo-controlled, phase 1/2a study (NCT03606512; https://www.clinicaltrials.gov/ct2/show/NCT03606512), RSV-seronegative toddlers aged 12-24 months received Ad26.RSV.preF (2.5 × 1010 viral particles) or placebo on days 1, 29, and 57 (a meningococcal vaccine [Nimenrix] could substitute for day 57 placebo). Primary endpoints were solicited local and systemic adverse events (AEs; 7 days after each vaccination), unsolicited AEs (28 days postvaccination), and serious AEs (first vaccination until study end). Participants were monitored for RSV-respiratory tract infection to assess infection rates and for severe RSV-lower respiratory tract infection as an indication of enhanced disease. RSV-A2 neutralizing, RSV (A and B) preF binding, and RSV postF immunoglobulin G-binding antibodies were evaluated on days 1 (predose), 8, and 85, and after RSV season 1.

Results

Thirty-eight participants were enrolled and vaccinated (Ad26.RSV.preF, n = 20; placebo, placebo/Nimenrix, n = 18). Solicited AEs were more common following Ad26.RSV.preF than placebo; most were mild/moderate. No vaccine-related serious AEs were reported. Five of 19 participants receiving Ad26.RSV.preF and 2/18 receiving placebo or placebo/Nimenrix had confirmed RSV-respiratory tract infection or RSV-associated otitis media; none were considered severe. At the final season 1 study visit, most Ad26.RSV.preF recipients had ≥2-fold increases from baseline in RSV-A2 neutralizing, RSV A and B preF binding, and RSV postF antibodies.

Conclusions

Ad26.RSV.preF was well tolerated and immunogenic in RSV-seronegative toddlers.

Palivizumab for the Prophylaxis of Respiratory Syncytial Virus Disease: Expert Opinion and Recommendations for the Gulf Cooperation Council Region

Respiratory syncytial virus (RSV) infection poses a significant health threat to infants and young children. Considering the substantial burden in Gulf Cooperation Council (GCC) countries, prevention of RSV remains a major public health priority. Globally, palivizumab prophylaxis has proven effective in reducing hospitalization and preventing complications in high-risk infants. While several national-level recommendations have been developed for palivizumab prophylaxis, few countries follow external guidelines due to a lack of regional directives. For effective RSV management, recommendations should be based on regional evidence and local clinical practices. Hence, it is imperative to establish uniform recommendations for palivizumab prophylaxis for the GCC region. We reviewed the literature on RSV prevalence, palivizumab immunoprophylaxis's efficacy, and the optimal timing for initiating RSV immunoprophylaxis programs. Experts were invited to share their insights on disease burden, current immunoprophylaxis practices, barriers to compliance, and strategies to improve adherence to palivizumab prophylaxis. These recommendations are intended to bridge the existing gaps and serve as a unified reference guide for local physicians and those recruiting eligible patients in RSV immunoprophylaxis programs, thus allowing for effective RSV management. This collaborative initiative aims to reduce the overall burden of RSV-related illness in the GCC region by promoting alignment in recommendations and addressing obstacles to compliance.

Risk factors for respiratory syncytial virus-associated acute lower respiratory infection in children under 5 years: An updated systematic review and meta-analysis

OBJECTIVES

Respiratory syncytial virus (RSV) is a leading cause of acute lower respiratory infection (ALRI) in young children. With substantial advances in RSV research, we aimed to conduct an updated systematic review of risk factors for RSV-ALRI in children under 5 years.

METHODS

We updated our previously published literature search to November 2022 among three English databases and additionally searched three Chinese databases (from January 1995) to identify all relevant publications. We performed random-effects meta-analyses to estimate the pooled odds ratio (OR) and 95% confidence interval (CI) for each risk factor and each outcome (RSV-ALRI in the community and RSV-ALRI hospitalization).

RESULTS

A total of 47 studies were included (26 from the updated search). Indoor air pollution was identified as a possible risk factor for RSV-ALRI in the community (OR 1.45, 95% CI: 1.10-1.90). The identified risk factors for RSV-ALRI hospitalization fall into four categories: demographic (male sex, Māori and Pacific ethnicities vs European or other ethnicities), pre- and post-neonatal (prematurity, low birth weight, small for gestational age, maternal smoking during pregnancy or lactation, maternal age <30 years vs 30-34 years, multiparity, caesarean section vs vaginal), household and environmental (having siblings, passive smoking, maternal asthma, daycare centre attendance) and health and medical conditions (any chronic diseases, bronchopulmonary dysplasia, HIV infections, congenital heart disease, Down syndrome, cystic fibrosis, previous asthma). The pooled ORs ranged from 1.14 to 4.55.

CONCLUSION

Our findings on the risk factors for RSV-ALRI help identify RSV high-risk groups, which has important implications for RSV prevention at both individual and population levels.

Respiratory Syncytial Virus Hospital Admission Rates and Patients' Characteristics Before the Age of 2 Years in England, 2015-2019

BACKGROUND

A granular understanding of respiratory syncytial virus (RSV) burden in England is needed to prepare for new RSV prevention strategies. We estimated the rates of RSV hospital admissions before the age of 2 years in England and described baseline characteristics.

METHODS

A birth cohort of all infants born between March 1, 2015, and February 28, 2017 (n = 449,591) was established using Clinical Practice Research Datalink-Hospital Episode Statistics. Case cohorts included infants with admission for (1) RSV, (2) bronchiolitis, (3) any respiratory tract infection (RTI) <24 months and (4) RSV predicted by an algorithm <12 months. Baseline characteristics were described in the case and comparative cohorts (infants without corresponding admission). Cumulative incidence and admission rates were calculated. Multiple linear regression was used to estimate the proportion of RTI healthcare visits attributable to RSV.

RESULTS

The RSV-coded/RSV-predicted case cohorts were composed of 4813/12,694 infants (cumulative incidence: 1.1%/2.8%). Case cohort infants were more likely to have low birth weight, comorbidities and to be born during RSV season than comparative cohort infants, yet >77% were term-healthy infants and >54% were born before the RSV season. During the first year of life, 11.6 RSV-coded and 34.4 RSV-predicted hospitalizations occurred per 1000 person-years. Overall, >25% of unspecified lower RTI admissions were estimated to be due to RSV.

CONCLUSIONS

In England, 1 in 91 infants had an RSV-coded admission, likely underestimated by ~3-fold. Most infants were term-healthy infants born before the RSV season. To decrease the total burden of RSV at the population level, immunization programs need to protect all infants.

Maternal Risk Factors for Respiratory Syncytial Virus Lower Respiratory Tract Infection in Otherwise Healthy Preterm and Term Infants: A Systematic Review and Meta-analysis

BACKGROUND/OBJECTIVE

To date, there is no published, formal assessment of all maternal risk factors for respiratory syncytial virus lower respiratory tract infection (RSV-LRTI) in infants. A systematic literature review and meta-analysis were undertaken to ascertain: What maternal risk factors are associated with an increased risk of RSV-LRTI in infants?

METHODS

The systematic literature review used explicit methods to identify, select and analyze relevant data. PubMed, Embase and the Cochrane Library were searched (November 2022) using terms regarding: (1) RSV/LRTI; (2) risk factors; (3) pregnant/postpartum population. Bayesian meta-analysis compared RSV hospitalization (RSVH) risk in infants born to mothers with or without certain risk factors.

RESULTS

A total of 2353 citations were assessed and 20 were included in the final review (10 individual studies; 10 pooled analyses). In 10 studies examining infants (<1 year) without comorbidities (primary outcome), 10 maternal risk factors were associated with RSV-LRTI/RSVH in multivariate analyses. Meta-analysis revealed smoking while pregnant increased infant RSVH risk by 2.01 (95% credible interval: 1.52-2.64) times, while breast-feeding was protective (0.73, 95% credible interval: 0.58-0.90). Risk scoring tools have reported that maternal risk factors contribute between 9% and 21% of an infant's total risk score for RSVH.

CONCLUSIONS

A greater understanding of maternal risk factors and their relative contribution to infant RSV-LRTI will enable more accurate assessments of the impact of preventive strategies.

The Multifaceted Burden of Respiratory Syncytial Virus (RSV) Infections in Young Children on the Family: A European Study

INTRODUCTION

Since the majority of hospitalisations due to RSV occur in young children, the illness profoundly influences the entire family. However, comprehensive evidence regarding its overall effects remains limited. The ResQ Family study aims to investigate the burden of RSV-induced pediatric hospitalisation on affected families.

METHODS

Spanning the 2022-2023 RSV season, an interdisciplinary, observational study was conducted in Germany, France, Italy and Sweden. Using an online questionnaire, parents and caregivers of children (< 24 months of age) with an RSV-induced hospitalisation were recruited. Information was gathered on topics related to RSV and parental health-related quality of life (HRQoL) during the acute infection phase (t0) and 6 weeks later (t1). Descriptive evaluations of the data set were performed during t0 and regarding a potential change over the observation period (t0 vs. t1). Subgroup analysis aimed to further identify differences across the countries.

RESULTS

A total set of 138 affected parents/caregivers were included in the study, with 59 participants responding to the follow-up survey (t1). Particularly during the acute infection phase, parental HRQoL was shown to be negatively influenced by the child's RSV infection [total score (p < 0.001, d = 0.54), parent HRQoL summary score (p < 0.001, d = 0.67) and family functioning summary score (p = 0.007, d = 0.33)]. Significant disparities in disease awareness and support structures were observed across Europe, with France and Sweden showing notably higher levels.

CONCLUSION

The ResQ Family study provides convincing evidence that RSV-associated hospitalisations in young children across Europe generate a multifaced burden for the entire family, partly even beyond the acute infection phase. Standardised approaches for disease prevention at societal, educational and policy levels are needed to guarantee every newborn the best possible start into life.

TRIAL REGISTRATION

ClinicalTrials.gov, identifier, NCT05550545.

Parent's perception of respiratory syncytial virus and subsequent wheezing burden: A multi-country cross-sectional survey

BACKGROUND

Respiratory Syncytial Virus (RSV) is the leading cause of hospitalization in infants. RSV bronchiolitis is associated with an increased risk of subsequent wheezing. We aimed to document the parents' perception of the link between RSV infection and subsequent wheezing, wheezing-related healthcare and family resources use, and its impact on family daily life.

METHODS

This cross-sectional online survey enrolled 1200 parents with at least one child ≤6y living in the United States, United Kingdom, Spain, and Italy. Children diagnosed with RSV bronchiolitis before age of 2 years were included in the RSV group, and those never diagnosed with RSV bronchiolitis in the Reference group.

RESULTS

The odds of wheezing were 4.5-fold (95%CI 3.5-5.9) higher in the RSV than in the Reference group. The odds increased to 7.7-fold (95%CI 5.4-11.1) among children who were hospitalized, and 9-fold (95%CI 5.1-16.6) among those admitted to pediatric intensive care with RSV bronchiolitis. Similar trends were observed across all countries. In total, 57% of parents reported their child's wheezing to have moderate to severe impact on their emotional well-being, and 53% on their daily life activities and/or social life. 64% of parents reported moderate-severe impact of wheezing on child's quality of sleep and 49% and 46% reported a moderate-severe impact on their children's emotional well-being and physical activities.

CONCLUSIONS

This survey suggests an association between RSV infection and subsequent wheezing in children across different countries. Wheezing, especially in association with RSV infection, was associated with increased healthcare utilization and costs, and significantly impacted parents' and children daily life.

Respiratory adenovirus infections in children: a focus on Africa

PURPOSE OF REVIEW

Lower respiratory tract infections (LRTIs) are an important cause of child morbidity and mortality globally, especially in children under the age of 5 years in Africa. Respiratory viruses, including human adenoviruses (HAdVs), are common causes of LRTIs in children. This review aims to shed light on the epidemiology, clinical manifestations, sequelae, and treatment options specific to adenovirus respiratory infections in African children.

RECENT FINDINGS

Recent evidence has challenged the perception that adenovirus is a negligible cause of LRTIs. Studies show HAdV emerging as the third most common viral pathogen in fatal pneumonias among under-5 children in low-income and middle-income African countries, contributing to 5.5% of all pneumonia deaths and ranking second in hospital-associated viral pneumonia deaths. Predominant HAdV serotypes associated with disease differ by country and region, and have changed over time. Risk factors for increased disease severity and long-term respiratory sequelae in previously healthy African children with HAdV LRTIs are not well established.

SUMMARY

Although respiratory viruses, including HAdV, are recognized contributors to LRTIs, the prevalence and impact of adenovirus infections have been under-recognized and understated. Available data suggests that African children, particularly those under 5 years old, are at risk of severe sequelae from respiratory HAdV infections. Long-term sequelae, including bronchiectasis and postinfectious bronchiolitis obliterans, further underscore the significant impact of HAdV infections. However, the scarcity of comprehensive data hampers our understanding of the extent of the impact of HAdV infections on child lung health in Africa. We recommend scaled-up HAdV surveillance, ensuring its consistent inclusion in population-level LRTI assessments, and expanded and equitable access to diagnostics for early recognition of African children at risk of developing chronic sequelae and death. Enhanced understanding of adenovirus epidemiology and clinical outcomes and the availability of therapeutic options are essential for informed public health strategies and clinical care.

Healthcare Providers' and Pregnant People's Preferences for a Preventive to Protect Infants from Serious Illness Due to Respiratory Syncytial Virus

We assessed the impact of respiratory syncytial virus (RSV) preventive characteristics on the intentions of pregnant people and healthcare providers (HCPs) to protect infants with a maternal vaccine or monoclonal antibodies (mAbs). Pregnant people and HCPs who treated pregnant people and/or infants were recruited via convenience sample from a general research panel to complete a cross-sectional, web-based survey, including a discrete choice experiment (DCE) wherein respondents chose between hypothetical RSV preventive profiles varying on five attributes (effectiveness, preventive type [maternal vaccine vs. mAb], injection recipient/timing, type of medical visit required to receive the injection, and duration of protection during RSV season) and a no-preventive option. A best-worst scaling (BWS) exercise was included to explore the impact of additional attributes on preventive preferences. Data were collected between October and November 2022. Attribute-level preference weights and relative importance (RI) were estimated. Overall, 992 pregnant people and 310 HCPs participated. A preventive (vs. none) was chosen 89.2% (pregnant people) and 96.0% (HCPs) of the time (DCE). Effectiveness was most important to preventive choice for pregnant people (RI = 48.0%) and HCPs (RI = 41.7%); all else equal, pregnant people (RI = 5.5%) and HCPs (RI = 7.2%) preferred the maternal vaccine over mAbs, although preventive type had limited influence on choice. Longer protection, protection starting at birth or the beginning of RSV season, and use for both pre-term and full-term babies were ranked highest in importance (BWS). Pregnant people and HCPs strongly preferred a preventive to protect infants against RSV (vs. none), underscoring the need to incorporate RSV preventives into routine care.

Short- and mid-term morbidity and primary-care burden due to infant respiratory syncytial virus infection: A Spanish 6-year population-based longitudinal study

BACKGROUND

The morbidity burden of respiratory syncytial virus (RSV) in infants extends beyond hospitalization. Defining the RSV burden before implementing prophylaxis programs is essential for evaluating any potential impact on short- to mid-term morbidity and the utilization of primary healthcare (PHC) and emergency services (ES). We established this reference data using a population-based cohort approach.

METHODS

Infants hospitalized for RSV from January 2016 to March 2023 were matched with non-hospitalized ones based on birthdate and sex. We defined the exposure as severe RSV hospitalization. The main study outcomes were as follows: (1) PHC and ES visits for RSV, categorized using the International Classification of Primary Care codes, (2) prescriptions for respiratory airway obstructive disease, and (3) antibacterial prescriptions. Participants were followed up from 30 days before hospitalization for severe RSV until the outcome occurrence or end of the study. Adjusted incidence rate ratios (IRRs) of the outcomes along with their 95% confidence intervals (CI) were estimated using Poisson regression models. Stratified analyses by type of PHC visit (nurse, pediatrician, or pharmacy) and follow-up period were undertaken. We defined mid-term outcomes as those taking place up to 24 months of follow-up period.

RESULTS

The study included 6626 children (3313 RSV-hospitalized; 3313 non-hospitalized) with a median follow-up of 53.7 months (IQR = 27.9, 69.4). After a 3-month follow-up, severe RSV was associated with a considerable increase in PHC visits for wheezing/asthma (IRR = 4.31, 95% CI: 3.84-4.84), lower respiratory infections (IRR = 4.91, 95% CI: 4.34-5.58), and bronchiolitis (IRR = 4.68, 95% CI: 2.93-7.65). Severe RSV was also associated with more PHC visits for the pediatrician (IRR = 2.00, 95% CI: 1.96-2.05), nurse (IRR = 1.89, 95% CI: 1.75-1.92), hospital emergency (IRR = 2.39, 95% CI: 2.17-2.63), primary healthcare emergency (IRR: 1.54, 95% CI: 1.31-1.82), as well as with important increase in prescriptions for obstructive airway diseases (IRR = 5.98, 95% CI: 5.43-6.60) and antibacterials (IRR = 4.02, 95% CI: 3.38-4.81). All findings remained substantial until 2 years of post-infection.

CONCLUSIONS

Severe RSV infection in infants significantly increases short- to mid-term respiratory morbidity leading to an escalation in healthcare utilization (PHC/ES attendance) and medication prescriptions for up to 2 years afterward. Our approach could be useful in assessing the impact and cost-effectiveness of RSV prevention programs.

Breath Markers of Oxidative Stress in Children with Severe Viral Lower Respiratory Tract Infection

Severe viral lower respiratory tract infection (LRTI), resulting in both acute and long-term pulmonary disease, constitutes a substantial burden among young children. Viral LRTI triggers local oxidative stress pathways by infection and inflammation, and supportive care in the pediatric intensive care unit may further aggravate oxidative injury. The main goal of this exploratory study was to identify and monitor breath markers linked to oxidative stress in children over the disease course of severe viral LRTI. Exhaled breath was sampled during invasive ventilation, and volatile organic compounds (VOCs) were analyzed using gas chromatography and mass spectrometry. VOCs were selected in an untargeted principal component analysis and assessed for change over time. In addition, identified VOCs were correlated with clinical parameters. Seventy breath samples from 21 patients were analyzed. A total of 15 VOCs were identified that contributed the most to the explained variance of breath markers. Of these 15 VOCs, 10 were previously linked to pathways of oxidative stress. Eight VOCs, including seven alkanes and methyl alkanes, significantly decreased from the initial phase of ventilation to the day of extubation. No correlation was observed with the administered oxygen dose, whereas six VOCs showed a poor to strong positive correlation with driving pressure. In this prospective study of children with severe viral LRTI, the majority of VOCs that were most important for the explained variance mirrored clinical improvement. These breath markers could potentially help monitor the pulmonary oxidative status in these patients, but further research with other objective measures of pulmonary injury is required.

Novel Approach for Detecting Respiratory Syncytial Virus in Pediatric Patients Using Machine Learning Models Based on Patient-Reported Symptoms: Model Development and Validation Study

BACKGROUND

Respiratory syncytial virus (RSV) affects children, causing serious infections, particularly in high-risk groups. Given the seasonality of RSV and the importance of rapid isolation of infected individuals, there is an urgent need for more efficient diagnostic methods to expedite this process.

OBJECTIVE

This study aimed to investigate the performance of a machine learning model that leverages the temporal diversity of symptom onset for detecting RSV infections and elucidate its discriminatory ability.

METHODS

The study was conducted in pediatric and emergency outpatient settings in Japan. We developed a detection model that remotely confirms RSV infection based on patient-reported symptom information obtained using a structured electronic template incorporating the differential points of skilled pediatricians. An extreme gradient boosting-based machine learning model was developed using the data of 4174 patients aged ≤24 months who underwent RSV rapid antigen testing. These patients visited either the pediatric or emergency department of Yokohama City Municipal Hospital between January 1, 2009, and December 31, 2015. The primary outcome was the diagnostic accuracy of the machine learning model for RSV infection, as determined by rapid antigen testing, measured using the area under the receiver operating characteristic curve. The clinical efficacy was evaluated by calculating the discriminative performance based on the number of days elapsed since the onset of the first symptom and exclusion rates based on thresholds of reasonable sensitivity and specificity.

RESULTS

Our model demonstrated an area under the receiver operating characteristic curve of 0.811 (95% CI 0.784-0.833) with good calibration and 0.746 (95% CI 0.694-0.794) for patients within 3 days of onset. It accurately captured the temporal evolution of symptoms; based on adjusted thresholds equivalent to those of a rapid antigen test, our model predicted that 6.9% (95% CI 5.4%-8.5%) of patients in the entire cohort would be positive and 68.7% (95% CI 65.4%-71.9%) would be negative. Our model could eliminate the need for additional testing in approximately three-quarters of all patients.

CONCLUSIONS

Our model may facilitate the immediate detection of RSV infection in outpatient settings and, potentially, in home environments. This approach could streamline the diagnostic process, reduce discomfort caused by invasive tests in children, and allow rapid implementation of appropriate treatments and isolation at home. The findings underscore the potential of machine learning in augmenting clinical decision-making in the early detection of RSV infection.

Balanced on the Biggest Wave: Nirsevimab for Newborns

Respiratory syncytial virus (RSV) is the leading cause of hospitalization in infancy in the United States. Nearly all infants are infected by 2 years of age, with bronchiolitis requiring hospitalization often occurring in previously healthy children and long-term consequences of severe disease including delayed speech development and asthma. Incomplete passage of maternal immunity and a high degree of genetic variability within the virus contribute to morbidity and have also prevented successful neonatal vaccine development. Monoclonal antibodies reduce the risk of hospitalization from severe RSV disease, with palivizumab protecting high-risk newborns with comorbidities including chronic lung disease and congenital heart disease. Unfortunately, palivizumab is costly and requires monthly administration of up to five doses during the RSV season for optimal protection.Rapid advances in the past two decades have facilitated the identification of antibodies with broad neutralizing activity and allowed manipulation of their genetic code to extend half-life. These advances have culminated with nirsevimab, a monoclonal antibody targeting the Ø antigenic site on the RSV prefusion protein and protecting infants from severe disease for an entire 5-month season with a single dose. Four landmark randomized controlled trials, the first published in July 2020, have documented the efficacy and safety of nirsevimab in healthy late-preterm and term infants, healthy preterm infants, and high-risk preterm infants and those with congenital heart disease. Nirsevimab reduces the risk of RSV disease requiring medical attention (number needed to treat [NNT] 14-24) and hospitalization (NNT 33-63) with rare mild rash and injection site reactions. Consequently, the Centers for Disease Control and Prevention has recently recommended nirsevimab for all infants younger than 8 months of age entering or born during the RSV season and high-risk infants 8-19 months of age entering their second season. Implementing this novel therapy in this large population will require close multidisciplinary collaboration. Equitable distribution through minimizing barriers and maximizing uptake must be prioritized.

Respiratory syncytial virus: A new era

Respiratory syncytial virus (RSV) is a major public health problem that has undergone significant changes in recent years. First of all, it has become easier to diagnose with highly reliable and rapidly available confirmatory tests. This has led to a better understanding of its epidemiology and RSV has gone from being a disease of the pediatric age group, severe only in infants and immunosuppressed children, to being a common disease in people of all ages, particularly important in patients of advanced age or with immunosuppressive diseases. Recent therapeutic and prophylactic advances, both with long-lasting monoclonal antibodies and vaccines, are another reason for satisfaction. For these reasons, the COVID and Emerging Pathogens Committee of the Illustrious Official College of Physicians of Madrid (ICOMEM) has considered it pertinent to review this subject in the light of new knowledge and new resources for dealing with this infection. We have formulated a series of questions that we believe will be of interest not only to members of the College but also to any non-expert in this subject, with a particular focus on the situation of RSV infection in Spain.

Understanding New Recommendations for Respiratory Syncytial Virus Prevention in Pregnancy

Respiratory syncytial virus (RSV) is a significant cause of infant morbidity and mortality worldwide with peak hospitalization rates for RSV-mediated illnesses between 2 and 3 months of life. Until very recently, prevention strategies for RSV involved primarily passive immunization of neonates at high risk with monoclonal antibodies and promotion of breastfeeding. The Centers for Disease Control and Prevention's (CDC) Advisory Committee on Immunization Practices now recommends passive immunization of all neonates with monoclonal antibodies during RSV season, and the American Association of Pediatrics has endorsed this practice. The U.S. Food and Drug Administration (FDA) recently approved a vaccination for RSV in pregnancy. The CDC's Advisory Committee on Immunization Practices has recently recommended RSV vaccination for all pregnant patients between 32 and 36 weeks of gestation who are anticipated to deliver during RSV season if they are not planning nirsevimab for their infants. This recommendation has been endorsed by the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine. In this clinical perspective, we review the scientific evidence, potential concerns, challenges, and future considerations for RSV vaccination in pregnancy.

Cooperative interaction of interferon regulatory factor -1 and bromodomain-containing protein 4 on RNA polymerase activation for intrinsic innate immunity

Introduction

The human orthopneumovirus, Respiratory Syncytial Virus (RSV), is the causative agent of severe lower respiratory tract infections (LRTI) and exacerbations of chronic lung diseases. In immune competent hosts, RSV productively infects highly differentiated epithelial cells, where it elicits robust anti-viral, cytokine and remodeling programs. By contrast, basal cells are relatively resistant to RSV infection, in part, because of constitutive expression of an intrinsic innate immune response (IIR) consisting of a subgroup of interferon (IFN) responsive genes. The mechanisms controlling the intrinsic IIR are not known.

Methods

Here, we use human small airway epithelial cell hSAECs as a multipotent airway stem cell model to examine regulatory control of an intrinsic IIR pathway.

Results

We find hSAECs express patterns of intrinsic IIRs, highly conserved with pluri- and multi-potent stem cells. We demonstrate a core intrinsic IIR network consisting of Bone Marrow Stromal Cell Antigen 2 (Bst2), Interferon Induced Transmembrane Protein 1 (IFITM1) and Toll-like receptor (TLR3) expression are directly under IRF1 control. Moreover, expression of this intrinsic core is rate-limited by ambient IRF1• phospho-Ser 2 CTD RNA Polymerase II (pSer2 Pol II) complexes binding to their proximal promoters. In response to RSV infection, the abundance of IRF1 and pSer2 Pol II binding is dramatically increased, with IRF1 complexing to the BRD4 chromatin remodeling complex (CRC). Using chromatin immunoprecipitation in IRF1 KD cells, we find that the binding of BRD4 is IRF1 independent. Using a small molecule inhibitor of the BRD4 acetyl lysine binding bromodomain (BRD4i), we further find that BRD4 bromodomain interactions are required for stable BRD4 promoter binding to the intrinsic IIR core promoters, as well as for RSV-inducible pSer2 Pol II recruitment. Surprisingly, BRD4i does not disrupt IRF1-BRD4 interactions, but disrupts both RSV-induced BRD4 and IRF1 interactions with pSer2 Pol II.

Conclusions

We conclude that the IRF1 functions in two modes- in absence of infection, ambient IRF1 mediates constitutive expression of the intrinsic IIR, whereas in response to RSV infection, the BRD4 CRC independently activates pSer2 Pol II to mediates robust expression of the intrinsic IIR. These data provide insight into molecular control of anti-viral defenses of airway basal cells.

The implication of infection with respiratory syncytial virus in pediatric recurrent wheezing and asthma: knowledge expanded post-COVID-19 era

BACKGROUND

Respiratory syncytial virus (RSV) infection has been identified to serve as the primary cause of acute lower respiratory infectious diseases in children under the age of one and a significant risk factor for the emergence and development of pediatric recurrent wheezing and asthma, though the exact mechanism is still unknown.

METHODS AND RESULTS

In this study, we discuss the key routes that lead to recurrent wheezing and bronchial asthma following RSV infection. It is interesting to note that following the coronavirus disease 2019 (COVID-19) epidemic, the prevalence of RSV changes significantly. This presents us with a rare opportunity to better understand the associated mechanism for RSV infection, its effects on the respiratory system, and the immunological response to RSV following the COVID-19 epidemic. To better understand the associated mechanisms in the occurrence and progression of pediatric asthma, we thoroughly described how the RSV infection directly destroys the physical barrier of airway epithelial tissue, promotes inflammatory responses, enhances airway hyper-responsiveness, and ultimately causes the airway remodeling. More critically, extensive discussion was also conducted regarding the potential impact of RSV infection on host pulmonary immune response.

CONCLUSION

In conclusion, this study offers a comprehensive perspective to better understand how the RSV infection interacts in the control of the host's pulmonary immune system, causing recurrent wheezing and the development of asthma, and it sheds fresh light on potential avenues for pharmaceutical therapy in the future.

Palivizumab prophylaxis in preterm infants and subsequent wheezing/asthma: 10-year follow-up study

BACKGROUND

Respiratory syncytial virus (RSV) causes not only infantile recurrent wheezing but also the development of asthma. To investigate whether palivizumab, an anti-RSV monoclonal antibody, prophylaxis given to preterm infants during the first RSV season reduces the incidence of subsequent recurrent wheezing and/or development of asthma, at 10 years of age.

METHODS

We conducted an observational prospective multicenter (52 registered hospitals in Japan) case-control study in preterm infants with a gestational age between 33 and 35 weeks followed for 6 years. During the 2007-2008 RSV season, the decision to administer palivizumab was made based on standard medical practice (SCELIA study). Here, we followed these subjects until 10 years of age. Parents of study subjects reported the patients' physician's assessment of recurrent wheezing/asthma, using a report card and a novel mobile phone-based reporting system using the internet. The relationship between RSV infection and asthma development, as well as the relationship between other factors and asthma development, were investigated.

RESULTS

Of 154 preterm infants enrolled, 113 received palivizumab during the first year of life. At 10 years, although both recurrent wheezing and development of asthma were not significantly different between the treated and untreated groups, maternal smoking with aeroallergen sensitization of the patients was significantly correlated with physician-diagnosed asthma.

CONCLUSIONS

In contrast to the prior study results at 6 years, by 10 years palivizumab prophylaxis had no impact on recurrent wheezing or asthma, but there was a significant correlation between maternal passive smoking with aeroallergen sensitization and development of asthma by 10 years of age.

Unmasking the potential of secretory IgA and its pivotal role in protection from respiratory viruses

Mucosal immunity has regained its spotlight amidst the ongoing Coronavirus disease 19 (COVID-19) pandemic, with numerous studies highlighting the crucial role of mucosal secretory IgA (SIgA) in protection against Severe acute respiratory syndrome coronavirus-2 or SARS-CoV-2 infections. The observed limitations in the efficacy of currently authorized COVID-19 vaccines in inducing effective mucosal immune responses remind us of the limitations of systemic vaccination in promoting protective mucosal immunity. This resurgence of interest has motivated the development of vaccine platforms capable of enhancing mucosal responses, specifically the SIgA response, and the development of IgA-based therapeutics. Recognizing viral respiratory infections as a global threat, we would like to comprehensively review the existing knowledge on mucosal immunity, with a particular emphasis on SIgA, in the context of SARS-CoV-2, influenza, and Respiratory Syncytial Virus (RSV) infections. This review aims to describe the structural and functional specificities of SIgA, along with its nuanced role in combating influenza, RSV, and SARS-CoV-2 infections. Subsequent sections further elaborate promising vaccine strategies, including mucosal vaccines against Influenza, RSV, and SARS-CoV-2 respiratory viruses, currently undergoing preclinical and clinical development. Additionally, we address the challenges associated with mucosal vaccine development, concluding with a discussion on IgA-based therapeutics as a promising platform for the treatment of viral respiratory infections. This comprehensive review not only synthesizes current insights into mucosal immunity but also identifies critical knowledge gaps, strengthening the way for further advancements in our current understanding and approaches to combat respiratory viral threats.

Value profile for respiratory syncytial virus vaccines and monoclonal antibodies

Respiratory syncytial virus (RSV) is the predominant cause of acute lower respiratory infection (ALRI) in young children worldwide, yet no licensed RSV vaccine exists to help prevent the millions of illnesses and hospitalizations and tens of thousands of young lives taken each year. Monoclonal antibody (mAb) prophylaxis exists for prevention of RSV in a small subset of very high-risk infants and young children, but the only currently licensed product is impractical, requiring multiple doses and expensive for the low-income settings where the RSV disease burden is greatest. A robust candidate pipeline exists to one day prevent RSV disease in infant and pediatric populations, and it focuses on two promising passive immunization approaches appropriate for low-income contexts: maternal RSV vaccines and long-acting infant mAbs. Licensure of one or more candidates is feasible over the next one to three years and, depending on final product characteristics, current economic models suggest both approaches are likely to be cost-effective. Strong coordination between maternal and child health programs and the Expanded Program on Immunization will be needed for effective, efficient, and equitable delivery of either intervention. This 'Vaccine Value Profile' (VVP) for RSV is intended to provide a high-level, holistic assessment of the information and data that are currently available to inform the potential public health, economic and societal value of pipeline vaccines and vaccine-like products. This VVP was developed by a working group of subject matter experts from academia, non-profit organizations, public private partnerships and multi-lateral organizations, and in collaboration with stakeholders from the WHO headquarters. All contributors have extensive expertise on various elements of the RSV VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using only existing and publicly available information.

Burden of Respiratory Viruses in Children Less Than 2 Years Old in a Community-based Longitudinal US Birth Cohort

BACKGROUND

Respiratory viral infections are a major cause of morbidity and hospitalization in young children. Nevertheless, the population burden of respiratory viral infections, especially asymptomatic cases, is not known due to the lack of prospective community-based cohort studies with intensive monitoring.

METHODS

To address this gap, we enacted the PREVAIL cohort, a Centers for Disease Control and Prevention-sponsored birth cohort in Cincinnati, Ohio, where children were followed from 0 to 2 years of age. Weekly text surveys were administered to record acute respiratory illnesses (ARIs), which were defined as the presence of cough or fever (≥38°C). Weekly midturbinate nasal swabs were collected and tested using the Luminex Respiratory Pathogen Panel, which detected 16 viral pathogens. Viral infection was defined as ≥1 positive tests from the same virus or viral subtype ≤30 days of a previous positive test. Maternal report and medical chart abstractions identified healthcare utilization.

RESULTS

From 4/2017 to 7/2020, 245 mother-infant pairs were recruited and followed. From the 13 781 nasal swabs tested, a total of 2211 viral infections were detected, of which 821 (37%) were symptomatic. Children experienced 9.4 respiratory viral infections/child-year; half were rhinovirus/enterovirus. Viral ARI incidence was 3.3 episodes/child-year. Emergency department visits or hospitalization occurred with only 15% of respiratory syncytial virus infections, 10% of influenza infections, and only 4% of all viral infections. Regardless of pathogen, most infections were asymptomatic or mild.

CONCLUSIONS

Respiratory viral infections are common in children 0-2 years. Most viral infections are asymptomatic or non-medically attended, underscoring the importance of community-based cohort studies.

The Path Towards Effective Respiratory Syncytial Virus Immunization Policies: Recommended Actions

The respiratory syncytial virus (RSV) causes a substantial burden worldwide. After over six decades of research, there is finally a licensed immunization option that can protect the broad infant population, and other will follow soon. RSV immunization should be in place from season 2023/2024 onwards. Doing so requires thoughtful but swift steps. This paper reflects the view of four immunization experts on the efforts being made across the globe to accommodate the new immunization options and provides recommendations organized around five priorities: (I) documenting the burden of RSV in specific populations; (II) expanding RSV diagnostic capacity in clinical practice; (III) strengthening RSV surveillance; (IV) planning for the new preventive options; (V) achieving immunization targets. Overall, Spain has been a notable example of converting RSV prevention into a national desideratum and has pioneered the inclusion of RSV in some of the regional immunization calendars for infants facing their first RSV season.

A new cost-utility analysis assessing risk factor-guided prophylaxis with palivizumab for the prevention of severe respiratory syncytial virus infection in Italian infants born at 29-35 weeks' gestational age

Since the last Italian cost-utility assessment of palivizumab in 2009, new data on the burden of respiratory syncytial virus (RSV) and an International Risk Scoring Tool (IRST) have become available. The objective of this study was to provide an up-to-date cost-utility assessment of palivizumab versus no prophylaxis for the prevention of severe RSV infection in otherwise healthy Italian infants born at 29-31 weeks' gestational age (wGA) infants and those 32-35wGA infants categorized as either moderate- or high-risk of RSV-hospitalization (RSVH) by the IRST. A decision tree was constructed in which infants received palivizumab or no prophylaxis and then could experience: i) RSVH; ii) emergency room medically-attended RSV-infection (MARI); or, iii) remain uninfected/non-medically attended. RSVH cases that required intensive care unit admission could die (0.43%). Respiratory morbidity was considered in all surviving infants up to 18 years of age. Hospitalization rates were derived from Italian data combined with efficacy from the IMpact-RSV trial. Palivizumab costs were calculated from vial prices (50mg: €490.37 100mg: €814.34) and Italian birth statistics combined with a growth algorithm. A lifetime horizon and healthcare and societal costs were included. The incremental cost-utility ratio (ICUR) was €14814 per quality-adjusted life year (QALY) gained in the whole population (mean: €15430; probability of ICUR being <€40000: 0.90). The equivalent ICURs were €15139 per QALY gained (€15915; 0.89) for 29-31wGA infants and €14719 per QALY gained (€15230; 0.89) for 32-35wGA infants. The model was most sensitive to rates of long-term sequelae, utility scores, palivizumab cost, and palivizumab efficacy. Palivizumab remained cost-effective in all scenario analyses, including a scenario wherein RSVH infants received palivizumab without a reduction in long-term sequelae and experienced a 6-year duration of respiratory morbidity (ICUR: €27948 per QALY gained). In conclusion, palivizumab remains cost-effective versus no prophylaxis in otherwise healthy Italian preterm infants born 29-35wGA. The IRST can help guide cost-effective use of palivizumab in 32-35wGA infants.

Risk of RSV-related hospitalization is associated with gestational age in preterm (born at 29-34 wGA) infants without outpatient palivizumab administration

Palivizumab has been shown to decrease RSV-related hospitalization (RSVH) risk and reduce RSVH severity. American Academy of Pediatrics (AAP) guidance on administration of palivizumab has changed over time; in 2014, palivizumab was no longer recommended in preterm infants born at 29 weeks gestational age (wGA) or later. This study's objective was to describe RSVH risk and severity in preterm infants (29-34 wGA) without comorbidities relative to healthy term infants and to each other by gestational age. Using the MarketScan Multi-State Medicaid and Commercial Databases, infants born from July 1, 2014 to June 30, 2019, at 29-34 wGA (preterm) and >37 wGA (term) were identified. During RSV seasons (November to March) from 2014 to 2020, claims incurred by infants while they were <6 months old were evaluated for RSVH and RSVH characteristics. This study included 63,351 preterm infants and 1,076,389 term infants without outpatient palivizumab administration. Rate of RSVH was higher in infants with lower wGA at birth and ranged 3.32-5.72 per 100 infant-seasons in Medicaid-insured infants and 3.21-4.84 in commercially insured infants. Relative risk of RSVH was 5-8 times higher in Medicaid-insured preterm infants and 3-5 times higher in commercially insured preterm infants compared to term infants. ICU admissions and mechanical ventilation were more common during RSVH in preterm infants relative to term infants. RSV-related outpatient healthcare utilization was also 2-3 times higher in preterm infants born at 31-34 wGA. Increased utilization of palivizumab among infants born at 29-34 wGA may decrease RSVH rates and result in less severe course in preterm infants with RSVH.

Understanding Policy Decisions and Their Implications Regarding Preventive Interventions for Respiratory Syncytial Virus (RSV) Infection in Canadian Infants: A Primer for Nurses

Respiratory syncytial virus (RSV) is a leading cause of morbidity and hospitalization in young children, and prevention is the primary management strategy. At present, palivizumab, a monoclonal antibody providing immediate passive immunity, rather than a vaccine that induces active immunity, is the only preventive intervention used in routine practice internationally. In Canada, access varies across the country. Prophylaxis policies are mainly driven by cost-effectiveness analyses, and it is crucial that the full costs and benefits of any intervention are captured. Positive results from a new Canadian cost-effectiveness analysis of palivizumab will help address the current inequality in use while providing a framework for future models of RSV preventives. Nurses are the principal educators for parents about the risks of childhood RSV and optimal prevention via basic hygiene, behavioral and environmental measures, and seasonal prophylaxis. Nurses should be provided not only with regular, up-to-date, and accurate information on RSV and the clinical aspects of emerging interventions but be informed on the decision-making governing the use of preventive strategies.

RSV replication modifies the XBP1s binding complex on the IRF1 upstream enhancer to potentiate the mucosal anti-viral response

Introduction

The unfolded protein response (UPR) has emerged as an important signaling pathway mediating anti-viral defenses to Respiratory Syncytial Virus (RSV) infection. Earlier we found that RSV replication predominantly activates the evolutionarily conserved Inositol Requiring Enzyme 1α (IRE1α)-X-Box Binding Protein 1 spliced (XBP1s) arm of the Unfolded Protein Response (UPR) producing inflammation, metabolic adaptation and cellular plasticity, yet the mechanisms how the UPR potentiates inflammation are not well understood.

Methods

To understand this process better, we examined the genomic response integrating RNA-seq and Cleavage Under Targets and Release Using Nuclease (CUT&RUN) analyses. These data were integrated with an RNA-seq analysis conducted on RSV-infected small airway cells ± an IRE1α RNAse inhibitor.

Results

We identified RSV induced expression changes in ~3.2K genes; of these, 279 required IRE1α and were enriched in IL-10/cytokine signaling pathways. From this data set, we identify those genes directly under XBP1s control by CUT&RUN. Although XBP1s binds to ~4.2 K high-confidence genomic binding sites, surprisingly only a small subset of IL10/cytokine signaling genes are directly bound. We further apply CUT&RUN to find that RSV infection enhances XBP1s loading on 786 genomic sites enriched in AP1/Fra-1, RELA and SP1 binding sites. These control a subset of cytokine regulatory factor genes including IFN response factor 1 (IRF1), CSF2, NFKB1A and DUSP10. Focusing on the downstream role of IRF1, selective knockdown (KD) and overexpression experiments demonstrate IRF1 induction controls type I and -III interferon (IFN) and IFN-stimulated gene (ISG) expression, demonstrating that ISG are indirectly regulated by XBP1 through IRF1 transactivation. Examining the mechanism of IRF1 activation, we observe that XBP1s directly binds a 5' enhancer sequence whose XBP1s loading is increased by RSV. The functional requirement for the enhancer is demonstrated by targeting a dCas9-KRAB silencer, reducing IRF1 activation. Chromatin immunoprecipitation shows that XBP1 is required, but not sufficient, for RSV-induced recruitment of activated phospho-Ser2 Pol II to the enhancer.

Discussion

We conclude that XBP1s is a direct activator of a core subset of IFN and cytokine regulatory genes in response to RSV. Of these IRF1 is upstream of the type III IFN and ISG response. We find that RSV modulates the XBP1s binding complex on the IRF1 5' enhancer whose activation is required for IRF1 expression. These findings provide novel insight into how the IRE1α-XBP1s pathway potentiates airway mucosal anti-viral responses.

Infection, Dysbiosis and Inflammation Interplay in the COVID Era in Children

For over three years, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children and adolescents has generated repercussions, especially a few weeks after infection, for symptomatic patients who tested positive, for asymptomatic ones, or even just the contacts of an infected person, and evolved from severe forms such as multisystem inflammatory syndrome in children (MIS-C) to multifarious clinical manifestations in long COVID (LC). Referred to under the umbrella term LC, the onset of persistent and highly heterogeneous symptoms such as fatigue, post-exertion malaise, cognitive dysfunction, and others have a major impact on the child's daily quality of life for months. The first aim of this review was to highlight the circumstances of the pathophysiological changes produced by COVID-19 in children and to better understand the hyperinflammation in COVID-19 and how MIS-C, as a life-threatening condition, could have been avoided in some patients. Another goal was to better identify the interplay between infection, dysbiosis, and inflammation at a molecular and cellular level, to better guide scientists, physicians, and pediatricians to advance new lines of medical action to avoid the post-acute sequelae of SARS-CoV-2 infection. The third objective was to identify symptoms and their connection to molecular pathways to recognize LC more easily. The fourth purpose was to connect the triggering factors of LC with related sequelae following acute SARS-CoV-2 injuries to systems and organs, the persistence of the virus, and some of its components in hidden reservoirs, including the gut and the central nervous system. The reactivation of other latent infectious agents in the host's immune environments, the interaction of this virus with the microbiome, immune hyperactivation, and autoimmunity generated by molecular mimicry between viral agents and host proteins, could initiate a targeted and individualized management. New high-tech solutions, molecules, probiotics, and others should be discovered to innovatively solve the interplay between RNA persistent viruses, microbiota, and our immune system.

Epidemiology and risk factors of respiratory syncytial virus associated acute respiratory tract infection in hospitalized children younger than 5 years from Sri Lanka

Background

Respiratory syncytial virus (RSV) is the leading cause of acute respiratory tract infections (ARTI) and a major cause of morbidity and mortality in children worldwide.

Aim

This study aimed to describe the prevalence and seasonal patterns of RSV and to determine the actual and predictive association of RSV-associated ARTI and clinical, socio-demographic, and climatic risk factors in children < 5 years.

Methods

Nasopharyngeal aspirates were collected from 500 children < 5 years admitted to the Kegalle General Hospital, Sri Lanka between May 2016 to July 2018. RSV and RSV subtypes were detected using immunofluorescence assay and real time RT-PCR, respectively. Descriptive and inferential statistics were done for the data analysis using Chi-square, Fisher's exact, Kruskal-Wallis test, and multiple binary logistic regression in the statistical package for social sciences (SPSS), version 16.0.

Results

Prevalence of RSV-associated ARTI was 28% in children < 5 years. Both RSV subtypes were detected throughout the study period. RSV-B was the dominant subtype detected with a prevalence of 72.14%. RSV infection in general caused severe respiratory disease leading to hypoxemia. Compared to RSV-B, RSV-A infection had more symptoms leading to hypoxemia. Factors increasing the risk of contracting RSV infection included number of people living (n > 6), having pets at home and inhaling toxic fumes. The inferential analysis predicts RSV infection in children < 5 years with ARTI, with a 75.4% probability with clinical and socio-demographic characteristics like age < 1 year, fever for > 4 days, cough, conjunctivitis, stuffiness, fatigue, six or more people at home, having pets at home and inhaling toxic fumes. Climatic factors like increases in temperature (°C), wind speed (Km/h), wind gust (Km/h), rainfall (mm) and atmospheric pressure (mb) showed a strong correlation with the RSV infection in children.

The effect of early childhood respiratory infections and pneumonia on lifelong lung function: a systematic review

Early childhood respiratory infections, including pneumonia, are an important global public health issue, with more than 40 million annual cases resulting in approximately 650 000 deaths. A growing number of published studies have examined the effects of early childhood lower respiratory tract infections (LRTIs) or pneumonia on lung function, particularly as part of large early-life exposure studies. To our knowledge, there is no published systematic review of these data. We searched PubMed, Embase, and Web of Science for studies published between database inception and May 12, 2022. Case-control, cohort, and cross-sectional studies were included if they reported forced expiratory volume in 1 s (FEV1) or forced vital capacity (FVC) values of participants older than 5 years. Article titles and abstracts were screened in Rayyan before retrieval, assessment, and data extraction of the full text. Primary outcome measures were differences in mean FEV1 or FVC values between exposed groups (ie, children aged ≤5 years with LRTIs) and non-exposed groups. This study is registered with PROSPERO, CRD42021265295. Database searches yielded 3070 articles, and 14 studies were included in this systematic review, providing a total of 23 276 participants, including 9969 children and 13 307 adults. Eight of 14 articles reported significant reductions in FEV1 values, and six of 12 studies reported reductions in FVC values in children and adults with a history of early childhood LRTIs or pneumonia, compared with unexposed controls (p<0·05). Most studies reporting reductions in lung function described deficits consistent with a restrictive spirometry pattern. Only two of 14 studies reported data from low-income and middle-income countries or disadvantaged populations in middle-income and high-income countries, and there were scarce data available on the effect of LRTI severity and recurrence on lung function. LRTIs in early childhood could be associated with a restrictive spirometry pattern in later childhood and adulthood. Data are needed from low-income and middle-income nations, and from disadvantaged populations in middle-income and high-income countries in which early childhood respiratory infection burden is disproportionately high. Data are also needed on the effect of LRTI severity and recurrence on future lung function.

Respiratory Syncytial Virus-An Update for Prenatal and Primary Health Providers

Respiratory syncytial virus (RSV) infection is a significant cause of morbidity and mortality among infants aged younger than 1 year, adults aged 65 years or older, and immunocompromised persons. Limited data exist on RSV infection in pregnancy and further research is needed. Strides are being made to develop vaccines, including vaccines for maternal immunization, as well as monoclonal antibodies for disease prevention.

Genomic targets of the IRE1-XBP1s pathway in mediating metabolic adaptation in epithelial plasticity

Epithelial mesenchymal plasticity (EMP) is a complex cellular reprogramming event that plays a major role in tissue homeostasis. Recently we observed the unfolded protein response (UPR) triggers EMP through the inositol-requiring protein 1 (IRE1α)-X-box-binding protein 1 spliced (XBP1s) axis, enhancing glucose shunting to protein N glycosylation. To better understand the genomic targets of XBP1s, we identified its genomic targets using Cleavage Under Targets and Release Using Nuclease (CUT&RUN) of a FLAG-epitope tagged XBP1s in RSV infection. CUT&RUN identified 7086 binding sites in chromatin that were enriched in AP-1 motifs and GC-sequences. Of these binding sites, XBP1s peaks mapped to 4827 genes controlling Rho-GTPase signaling, N-linked glycosylation and ER-Golgi transport. Strikingly, XBP1s peaks were within 1 kb of transcription start sites of 2119 promoters. In addition to binding core mesenchymal transcription factors SNAI1 and ZEB1, we observed that hexosamine biosynthetic pathway (HBP) enzymes were induced and contained proximal XBP1s peaks. We demonstrate that IRE1α -XBP1s signaling is necessary and sufficient to activate core enzymes by recruiting elongation-competent phospho-Ser2 CTD modified RNA Pol II. We conclude that the IRE1α-XBP1s pathway coordinately regulates mesenchymal transcription factors and hexosamine biosynthesis in EMP by a mechanism involving recruitment of activated pSer2-Pol II to GC-rich promoters.

Impact of using the International Risk Scoring Tool on the cost-utility of palivizumab for preventing severe respiratory syncytial virus infection in Canadian moderate-to-late preterm infants

BACKGROUND AND OBJECTIVE

To assess the cost-utility of palivizumab versus no prophylaxis in preventing severe respiratory syncytial virus (RSV) infection in Canadian moderate-to-late preterm (32-35 weeks' gestational age) infants using an: i) International Risk Scoring Tool (IRST); ii) Canadian RST (CRST).

METHODS

A decision tree was developed to assess cost-utility. Infants assessed at moderate- and high-risk of RSV-related hospitalization (RSVH) by the IRST or CRST received palivizumab or no prophylaxis and then progressed to either: i) RSVH; ii) emergency room/outpatient medically attended RSV-infection (MARI); or, iii) were uninfected/non-medically attended. Infants admitted to intensive care could incur mortality (0.43%). Respiratory morbidity was accounted in all uninfected surviving infants for 6 years or 18 years (RSVH/MARI). Palivizumab efficacy (72.2% RSVH reduction) and hospital outcomes were from the Canadian CARESS, PICNIC and RSV-Quebec studies. Palivizumab costs (50mg: CAN$752; 100mg: $1,505) were calculated from Canadian birth statistics combined with a growth algorithm. Healthcare/payer and societal costs (May 2022; 1.5% discounting) were included.

RESULTS

Cost per quality-adjusted life year (QALY) was $29,789 with the IRST (0.79 probability of being <$50,000) and $15,833 with the CRST (0.96 probability). The model was most sensitive to utility scores, long-term sequelae, and palivizumab cost. Vial sharing improved the incremental cost-utility ratio (IRST: $22,319; CRST: $9,231).

CONCLUSIONS

Palivizumab was highly cost-effective (vs no prophylaxis) in Canadian moderate-to-late preterm infants using either the IRST or CRST. The IRST has fewer risk factors than the CRST (3 vs 7, respectively), captures more potential RSVHs (85% vs 54%) and provides another option to guide cost-effective RSV prophylaxis in Canada.

Health inequalities in infectious diseases: a systematic overview of reviews

OBJECTIVES

The aim of this systematic overview of reviews was to synthesise available evidence on inequalities in infectious disease based on three dimensions of inequalities; inclusion health groups, protected characteristics and socioeconomic inequalities.

METHODS

We searched MEDLINE, Embase, Web of Science and OpenGrey databases in November 2021. We included reviews published from the year 2000 which examined inequalities in the incidence, prevalence or consequences of infectious diseases based on the dimensions of interest. Our search focused on tuberculosis, HIV, sexually transmitted infections, hepatitis C, vaccination and antimicrobial resistance. However, we also included eligible reviews of any other infectious diseases. We appraised the quality of reviews using the Assessment of Multiple Systematic Reviews V.2 (AMSTAR2) checklist. We conducted a narrative data synthesis.

RESULTS

We included 108 reviews in our synthesis covering all the dimensions of inequalities for most of the infectious disease topics of interest, however the quality and volume of review evidence and consistency of their findings varied. The existing literature reviews provide strong evidence that people in inclusion health groups and lower socioeconomic status are consistently at higher risk of infectious diseases, antimicrobial resistance and incomplete/delayed vaccination. In the protected characteristics dimension, ethnicity, and sexual orientation are important factors contributing to inequalities across the various infectious disease topics included in this overview of reviews.

CONCLUSION

We identified many reviews that provide evidence of various types of health inequalities in different infectious diseases, vaccination, and antimicrobial resistance. We also highlight areas where reviews may be lacking. The commonalities in the associations and their directions suggest it might be worth targeting interventions for some high risk-groups that may have benefits across multiple infectious disease outcomes rather than operating purely in infectious disease siloes.

Chest physiotherapy for acute bronchiolitis in paediatric patients between 0 and 24 months old

BACKGROUND

Acute bronchiolitis is the leading cause of medical emergencies during winter months in infants younger than 24 months old. Chest physiotherapy is sometimes used to assist infants in the clearance of secretions in order to decrease ventilatory effort. This is an update of a Cochrane Review first published in 2005 and updated in 2006, 2012, and 2016.

OBJECTIVES

To determine the efficacy of chest physiotherapy in infants younger than 24 months old with acute bronchiolitis. A secondary objective was to determine the efficacy of different techniques of chest physiotherapy (vibration and percussion, passive exhalation, or instrumental).

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, Web of Science, PEDro (October 2011 to 20 April 2022), and two trials registers (5 April 2022).

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which chest physiotherapy was compared to control (conventional medical care with no physiotherapy intervention) or other respiratory physiotherapy techniques in infants younger than 24 months old with bronchiolitis.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

Our update of the searches dated 20 April 2022 identified five new RCTs with 430 participants. We included a total of 17 RCTs (1679 participants) comparing chest physiotherapy with no intervention or comparing different types of physiotherapy. Five trials (246 participants) assessed percussion and vibration techniques plus postural drainage (conventional chest physiotherapy), and 12 trials (1433 participants) assessed different passive flow-oriented expiratory techniques, of which three trials (628 participants) assessed forced expiratory techniques, and nine trials (805 participants) assessed slow expiratory techniques. In the slow expiratory subgroup, two trials (78 participants) compared the technique with instrumental physiotherapy techniques, and two recent trials (116 participants) combined slow expiratory techniques with rhinopharyngeal retrograde technique (RRT). One trial used RRT alone as the main component of the physiotherapy intervention. Clinical severity was mild in one trial, severe in four trials, moderate in six trials, and mild to moderate in five trials. One study did not report clinical severity. Two trials were performed on non-hospitalised participants. Overall risk of bias was high in six trials, unclear in five, and low in six trials. The analyses showed no effects of conventional techniques on change in bronchiolitis severity status, respiratory parameters, hours with oxygen supplementation, or length of hospital stay (5 trials, 246 participants).  Regarding instrumental techniques (2 trials, 80 participants), one trial observed similar results in bronchiolitis severity status when comparing slow expiration to instrumental techniques (mean difference 0.10, 95% confidence interval (C) -0.17 to 0.37).  Forced passive expiratory techniques failed to show an effect on bronchiolitis severity in time to recovery (2 trials, 509 participants; high-certainty evidence) and time to clinical stability (1 trial, 99 participants; high-certainty evidence) in infants with severe bronchiolitis. Important adverse effects were reported with the use of forced expiratory techniques.  Regarding slow expiratory techniques, a mild to moderate improvement was observed in bronchiolitis severity score (standardised mean difference -0.43, 95% CI -0.73 to -0.13; I2 = 55%; 7 trials, 434 participants; low-certainty evidence). Also, in one trial an improvement in time to recovery was observed with the use of slow expiratory techniques. No benefit was observed in length of hospital stay, except for one trial which showed a one-day reduction. No effects were shown or reported for other clinical outcomes such as duration on oxygen supplementation, use of bronchodilators, or parents' impression of physiotherapy benefit.

AUTHORS' CONCLUSIONS

We found low-certainty evidence that passive slow expiratory technique may result in a mild to moderate improvement in bronchiolitis severity when compared to control. This evidence comes mostly from infants with moderately acute bronchiolitis treated in hospital. The evidence was limited with regard to infants with severe bronchiolitis and those with moderately severe bronchiolitis treated in ambulatory settings. We found high-certainty evidence that conventional techniques and forced expiratory techniques result in no difference in bronchiolitis severity or any other outcome. We found high-certainty evidence that forced expiratory techniques in infants with severe bronchiolitis do not improve their health status and can lead to severe adverse effects. Currently, the evidence regarding new physiotherapy techniques such as RRT or instrumental physiotherapy is scarce, and further trials are needed to determine their effects and potential for use in infants with moderate bronchiolitis, as well as the potential additional effect of RRT when combined with slow passive expiratory techniques. Finally, the effectiveness of combining chest physiotherapy with hypertonic saline should also be investigated.

Post-TB health and wellbeing

TB affects around 10.6 million people each year and there are now around 155 million TB survivors. TB and its treatments can lead to permanently impaired health and wellbeing. In 2019, representatives of TB affected communities attending the '1st International Post-Tuberculosis Symposium´ called for the development of clinical guidance on these issues. This clinical statement on post-TB health and wellbeing responds to this call and builds on the work of the symposium, which brought together TB survivors, healthcare professionals and researchers. Our document offers expert opinion and, where possible, evidence-based guidance to aid clinicians in the diagnosis and management of post-TB conditions and research in this field. It covers all aspects of post-TB, including economic, social and psychological wellbeing, post TB lung disease (PTLD), cardiovascular and pericardial disease, neurological disability, effects in adolescents and children, and future research needs.

An analysis of risk factors associated with recurrent wheezing in the pediatric population

BACKGROUND

Recurrent wheezing is a common clinical problem in early childhood, which is associated with significant morbidity. There is no international consensus on the management and prevention of recurrent wheezing; therefore, identifying the risk factors associated with recurrent wheezing is crucial to prevent episodes of wheezing in young children.

METHODS

In this retrospective study, we collected the data of 24,737 patients who were admitted to our hospital between 27th April 2012 and 11th September 2019. After screening for patients with wheezing, we identified 8572 patients with a primary diagnosis of pneumonia with wheezing. Patients' clinical data were collected from the hospital medical records. Patients were stratified for age in the groups of < 6 months, 6-12 months, and > 12 months.

RESULTS

Among the 8569 pediatric pneumonia patients with wheezing, there were 343 patients with recurrent wheezing. Most enrolled patients were under 6 months of age (45.17%) and had a normal birth weight (86.95%). Winter was the most common onset season for the first episode of wheezing, while spring was the most common season for the second episode of wheezing for those with recurrent wheezing. The univariate and multivariate logistic regression analysis for the risk factor associated with recurrent wheezing showed that male gender, past history of respiratory and cardiovascular diseases, low birth weight, development of severe pneumonia, and PICU admission were significantly associated with recurrent wheezing.

CONCLUSION

Male gender, past history of respiratory and cardiovascular diseases, low birth weight, severe pneumonia, and PICU admission are independent risk factors of recurrent wheezing in the pediatric population.