Respiratory Syncytial Virus Hospitalization Research Articles

RSV Risk Profile in Hospitalized Adults and Comparison with Influenza and COVID-19 Controls in Valladolid, Spain, 2010-2022.

We aimed to describe the risk profile of respiratory syncytial virus (RSV) infections among adults ≥ 60years in Valladolid from January 2010 to August 2022, and to compare them with influenza and COVID-19 controls. This was a retrospective cohort study of all laboratory-confirmed RSV infections identified in centralized microbiology database during a 12-year period. We analyzed risk factors for RSV hospitalization and severity (length of stay, intensive care unit admission, in-hospital death or readmission < 30days) and compared severity between RSV patients vs. influenza and COVID-19 controls using multivariable logistic regression models. We included 706 RSV patients (635 inpatients and 71 outpatients), and 598 influenza and 60 COVID-19 hospitalized controls with comparable sociodemographic profile. Among RSV patients, 96 (15%) had a subtype identified: 56% A, 42% B, and 2% A + B. Eighty-one percent of RSV patients had cardiovascular conditions, 65% endocrine/metabolic, 46% chronic lung, and 43% immunocompromising conditions. Thirty-six percent were coinfected (vs. 21% influenza and 20% COVID-19; p = < .0001 and 0.01). Ninety-two percent had signs of lower respiratory infection (vs. 85% influenza and 72% COVID-19, p = < .0001) and 27% cardiovascular signs (vs. 20% influenza and 8% COVID-19, p = 0.0031 and 0.0009). Laboratory parameters of anemia, inflammation, and hypoxemia were highest in RSV. Among RSV, being a previous smoker (adjustedOR 2.81 [95% CI 1.01, 7.82]), coinfection (4.34 [2.02, 9.34]), and having cardiovascular (3.79 [2.17, 6.62]), neurologic (2.20 [1.09, 4.46]), or chronic lung (1.93 [1.11, 3.38]) diseases were risks for hospitalization. Being resident in care institutions (1.68 [1.09, 2.61]) or having a coinfection (1.91[1.36, 2.69]) were risks for higher severity, while RSV subtype was not associated with severity. Whereas RSV and influenza patients did not show differences in severity, RSV patients had 68% (38-84%) lower odds of experiencing any severe outcome compared to COVID-19. RSV especially affects those with comorbidities, coinfections, and living in care institutions. RSV vaccination could have an important public health impact in this population.

Estimated Incidence of Hospitalizations Attributable to RSV Infection Among Adults in Ontario, Canada, Between 2013 and 2019.

Adult respiratory syncytial virus (RSV) burden is underestimated due to non-specific symptoms, limited standard-of-care and delayed testing, reduced diagnostic test sensitivity-particularly when using single diagnostic specimen-when compared to children, and variable test sensitivity based on the upper airway specimen source. We estimated RSV-attributable hospitalization incidence among adults aged ≥ 18 years in Ontario, Canada, using a retrospective time-series model-based approach. The Institute for Clinical Evaluative Sciences data repository provided weekly numbers of hospitalizations (from 2013 to 2019) for respiratory, cardiovascular, and cardiorespiratory disorders. The number of hospitalizations attributable to RSV was estimated using a quasi-Poisson regression model that considered probable overdispersion and was based on periodic and aperiodic time trends and viral activity. As proxies for viral activity, weekly counts of RSV and influenza hospitalizations in children under 2 years and adults aged 60 years and over, respectively, were employed. Models were stratified by age and risk group. In patients ≥ 60 years, RSV-attributable incidence rates were high for cardiorespiratory hospitalizations (range [mean] in 2013-2019: 186-246 [215] per 100,000 person-years, 3‒4% of all cardiorespiratory hospitalizations), and subgroups including respiratory hospitalizations (144-192 [167] per 100,000 person-years, 5‒7% of all respiratory hospitalizations) and cardiovascular hospitalizations (95-126 [110] per 100,000 person-years, 2‒3% of all cardiovascular hospitalizations). RSV-attributable cardiorespiratory hospitalization incidence increased with age, from 14-18 [17] hospitalizations per 100,000 person-years (18-49 years) to 317-411 [362] per 100,000 person-years (≥ 75 years). Estimated RSV-attributable respiratory hospitalization incidence among people ≥ 60 years in Ontario, Canada, is comparable to other incidence estimates from high-income countries, including model-based and pooled prospective estimates. Recently introduced RSV vaccines could have a substantial public health impact.

Neighborhood-Level Burden of Social Risk Factors on Respiratory Syncytial Virus Hospitalization in Ontario, Canada, 2016-2019.

Beyond clinical risk factors, little is known about the impact of social determinants on respiratory syncytial virus (RSV) burden. Our study aimed to estimate RSV-related hospitalization rates across sociodemographic and housing characteristics. We conducted a population-based study of all RSV-related hospitalizations in Ontario, Canada, between September 1, 2016, and August 31, 2019, using validated hospital discharge codes and census data. Crude and age-standardized annualized RSV incidence rates and rate ratios (RRs) were estimated for a range of individual-level demographics and neighborhood-level measures of marginalization and housing characteristics. Overall, the annual RSV-related hospitalization rate was 27 per 100 000, with the highest rates observed in children age <12 months (1049 per 100 000) and 12-23 months (294 per 100 000) and adults age ≥85 years (155 per 100 000). Higher RSV-related hospitalization rates were associated with increasing marginalization quintile (Q) of material resources (RR, 1.4; Q5: 33 per 100 000 vs Q1: 24 per 100 000) and household instability (RR, 1.5; Q5: 31 per 100 000 vs Q1: 22 per 100 000). The burden of RSV-related hospitalization was greatest in young children and older adults, with variation by sociodemographic and housing factors. Understanding the role of these social factors is crucial for informing equitable preventive program delivery.

Economic burden of cardiorespiratory hospitalizations associated with respiratory syncytial virus among United States adults in 2017–2019

ABSTRACT Morbidity and mortality caused by respiratory syncytial virus (RSV) in older adults and those with underlying health conditions can be potentially alleviated through vaccination. To assist vaccine policy decision-makers and payers, we estimated the annual economic burden of RSV-associated cardiorespiratory hospitalizations among insured US adults aged ≥18 y in the Merative MarketScan claims database from September through August of 2017–2018 and 2018–2019. Negative binomial regression models were used to estimate the number of RSV-associated cardiorespiratory hospitalizations using MarketScan-identified cardiorespiratory diagnosis codes in the presence or absence of RSV circulation per weekly laboratory test positivity percentages from the Centers for Disease Control and Prevention. This number was multiplied by mean cardiorespiratory hospitalization costs to estimate total costs for RSV-associated cardiorespiratory hospitalizations. Number and cost for International Classification of Diseases (ICD)-coded RSV hospitalizations were quantified from MarketScan. In 2017–2018 and 2018–2019, respectively, 18,515,878 and 16,462,120 adults with commercial or Medicare supplemental benefits were assessed. In 2017–2018, 301,248 cardiorespiratory hospitalizations were observed; 0.32% had RSV-specific ICD codes, costing $44,916,324, and 5.52% were RSV-associated cardiorespiratory hospitalizations, costing $734,078,602 (95% CI: $460,826,580–$1,103,358,799). In 2018–2019, 215,525 cardiorespiratory hospitalizations were observed; 0.34% had RSV-specific ICD codes, costing $33,053,105, and 3.14% were RSV-associated cardiorespiratory hospitalizations, costing $287,549,472 (95% CI: $173,377,778–$421,884,259). RSV contributes to substantial economic burden of cardiorespiratory hospitalizations among US adults. Modeling excess risk using viral positivity data provides a comprehensive estimation of RSV hospitalization burden and associated costs, compared with relying on ICD diagnosis codes alone.

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

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. 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. 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. 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.

Comparison of the Burden and Temporal Pattern of Hospitalisations Associated With Respiratory Syncytial Virus (RSV) Before and After COVID-19 in New Zealand.

Changes in the epidemiology of illnesses caused by respiratory syncytial virus (RSV) infection following the COVID-19 pandemic are reported. The New Zealand (NZ) COVID-19 situation was unique; RSV community transmission was eliminated with the 2020 border closure, with a rapid and large increase in hospitalizations following the relaxation of social isolation measures and the opening of an exclusive border with Australia. This active population-based surveillance compared the age-specific incidence and seasonality of RSV-associated hospitalizations in Auckland, NZ, for 2 years before and after the 2020 border closures. Hospitalisation rates between years were compared by age, ethnicity (European/other, Māori, Pacific and Asian) and socioeconomic group (1 = least, 5 = most deprived). There was no RSV transmission in 2020. In all other years, hospitalisation rates were highest for people of Pacific versus other ethnic groups and for people living in the most deprived quintile of households. RSV hospitalisation rates were higher in 2021 and 2022 than in 2018-19. The epidemic peak was higher in 2021, but not 2022, and the duration was shorter than in 2018-19. In 2021, the increase in RSV hospitalisation rates was significant across all age, sex, ethnic and socioeconomic groups. In 2022, the increase in hospitalisation rates was only significant in one age (1- < 3 years), one ethnic (Asian) and one socioeconomic group (quintile 2). COVID pandemic responses altered RSV-related hospitalisation seasonal patterns. Atypical features of RSV hospitalisation epidemiology were the increase in rates in older children and young adults, which lessened in 2022. Despite these variations, RSV hospitalisations in NZ continue to disproportionately affect individuals of Pacific ethnicity and those living in more socioeconomically deprived households. Whilst future public health strategies focused on RSV disease mitigation need to consider the potential shifts in epidemiological patterns when the transmission is disrupted, these variances must be considered in the context of longer-standing patterns of unequal disease distribution.

Inconsistent Increase in Age at Respiratory Syncytial Virus Hospitalization of Children Aged

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic disrupted respiratory syncytial virus (RSV) seasonality. To optimize the use and evaluation of RSV infant immunization strategies, monitoring changes in RSV epidemiology is essential. Hospitalizations for acute respiratory infections (ARIs) and RSV-coded ARI in children <2 years were extracted in 4 European hospitals, according to predefined case definitions (International Classification of Diseases, Tenth Revision codes). Prepandemic RSV seasons (2017-2018 to 2019-2020) were compared to 2021-2022 and 2022-2023. In 2021-2022 and 2022-2023, the peak number of RSV hospitalizations was higher than prepandemic peaks after short periods of RSV circulation, and lower than prepandemic peaks after long periods of RSV circulation. A greater proportion of RSV hospitalizations occurred in children 1 to <2 years in 2021-2022 in the Netherlands (18% vs 9%, P = .04). No increase in age was observed elsewhere. High-risk children represented a greater proportion of RSV hospitalizations during the pandemic. The proportion of pediatric intensive care unit admissions did not increase. A decrease in population immunity has been linked to older age at RSV hospitalization. We did not observe an increase in age in 3 of the 4 participating countries. Broad age categories may have prevented detecting an age shift. Monitoring RSV epidemiology is essential as Europe implements RSV immunization.

Pediatric Respiratory Syncytial Virus Hospitalizations and Respiratory Support After the COVID-19 Pandemic

After the COVID-19 pandemic, there was a surge of pediatric respiratory syncytial virus (RSV) infections, but national data on hospitalization and intensive care unit use and advanced respiratory support modalities have not been reported. To analyze demographics, respiratory support modes, and clinical outcomes of children with RSV infections at tertiary pediatric hospitals from 2017 to 2023. This cross-sectional study evaluated children from 48 freestanding US children's hospitals registered in the Pediatric Health Information System (PHIS) database. Patients 5 years or younger with RSV from July 1, 2017, to June 30, 2023, were included. Each season was defined from July 1 to June 30. Prepandemic RSV seasons included 2017 to 2018, 2018 to 2019, and 2019 to 2020. The postpandemic season was delineated as 2022 to 2023. Hospital presentation with RSV infection. Data on emergency department presentations, hospital or intensive care unit admission and length of stay, demographics, respiratory support use, mortality, and cardiopulmonary resuscitation were analyzed. Postpandemic season data were compared with prepandemic seasonal averages. A total of 288 816 children aged 5 years or younger (median [IQR] age, 8.9 [3.3-21.5] months; 159 348 [55.2%] male) presented to 48 US children's hospitals with RSV from July 1, 2017, to June 30, 2023. Respiratory syncytial virus hospital presentations increased from 39 698 before the COVID-19 pandemic to 94 347 after the pandemic (P < .001), with 86.7% more hospitalizations than before the pandemic (50 619 vs 27 114; P < .001). In 2022 to 2023, children were older (median [IQR] age, 11.3 [4.1-26.6] months vs 6.8 [2.6-16.8] months; P < .001) and had fewer comorbidities (17.6% vs 21.8% of hospitalized patients; P < .001) than during prepandemic seasons. Advanced respiratory support use increased 70.1% in 2022 to 2023 (9094 vs 5340; P < .001), and children requiring high-flow nasal cannula (HFNC) or noninvasive ventilation (NIV) were older than during prepandemic seasons (median [IQR] age for HFNC, 6.9 [2.7-16.0] months vs 4.6 [2.0-11.7] months; for NIV, 6.0 [2.1-16.5] months vs 4.3 [1.9-11.9] months). Comorbid conditions were less frequent after the pandemic across all respiratory support modalities (HFNC, 14.9% vs 19.1%, NIV, 22.0% vs 28.5%, invasive mechanical ventilation, 30.5% vs 38.0%; P < .001). This cross-sectional study identified a postpandemic pediatric RSV surge that resulted in markedly increased hospital volumes and advanced respiratory support needs in older children with fewer comorbidities than prepandemic seasons. These clinical trends may inform novel vaccine allocation to reduce the overall burden during future RSV seasons.

Pediatric Respiratory Syncytial Virus Hospitalizations, 2017-2023

Respiratory syncytial virus (RSV) transmission was disrupted worldwide following the COVID-19 pandemic, and further study is required to better understand these changes. To compare observed and expected RSV hospital and intensive care unit (ICU) admission rates and characteristics of admitted children during the 2021-2022 and 2022-2023 seasons. A population-based cohort study of all children aged younger than 5 years in Ontario, Canada, July 1, 2017, through March 31, 2023, was conducted. Individual and neighborhood-level sociodemographic and clinical characteristics were identified from administrative data, including age, palivizumab eligibility, complex medical conditions, rurality, and living in a marginalized neighborhood. The main outcome was RSV-associated hospitalization. Secondary outcomes included ICU admissions, mechanical ventilation, extracorporeal membrane oxygenation, and in-hospital death. Poisson generalized estimating equations were used to model weekly age- and sex-specific hospitalization rates and estimate expected rates in the postpandemic era; adjusted rate ratios (RRs) and 95% CIs are reported. This cohort study included approximately 700 000 children per study year. Compared with prepandemic years (2017-2018, 2018-2019, and 2019-2020), the 2021-2022 RSV season peaked slightly earlier, but overall admission rates were comparable (289.1 vs 281.4-334.6 per 100 000, or approximately 2000 admissions). The 2022-2023 season peaked a month earlier and resulted in more than twice as many hospitalizations (770.0 per 100 000; n = 4977 admissions). The proportion of children admitted to an ICU in 2022-2023 (13.9%) was slightly higher than prepandemic (9.6%-11.4%); however, the population-based rate was triple the prepandemic levels (106.9 vs 27.6-36.6 per 100 000 children in Ontario). With the exception of palivizumab-eligible children, all sociodemographic and health status characteristics were associated with lower-than-expected RSV hospitalization rates in 2021-2022. In contrast, older age of patients was associated with higher-than-expected rates in 2022-2023 (ie, 24-59 months: RR, 1.90; 95% CI, 1.35-2.66). There were notable differences in RSV epidemiologic characteristics in Ontario following the COVID-19 pandemic. It is not yet clear whether and how long atypical RSV epidemics may persist. Clinicians and program planners should consider the potential for ongoing impacts to health care capacity and RSV immunization programs.

Cost-Effectiveness Analysis of Maternal Respiratory Syncytial Virus Vaccine in Protecting Infants from RSV Infection in Japan.

Respiratory syncytial virus (RSV) is one of the major causes of respiratory tract infections among children. Until recently, the monoclonal antibody palivizumab was the only RSV prophylaxis available in Japan. In 2024, the bivalent RSV prefusion F protein-based (RSVpreF) vaccine was approved for the prevention of RSV infection in infants by active immunization of pregnant women. In this study, we assessed the cost-effectiveness of a combined strategy of RSVpreF vaccine and palivizumab in Japanese setting. Using a Markov model, we evaluated prevented cases and deaths of medically attended RSV infections from birth to age 11months for each of the three healthcare settings: inpatient (hospitalization), emergency department visits, and outpatient visits. Incremental cost-effectiveness ratios (ICERs) were calculated from economic outcomes (intervention costs, medication costs, and productivity losses) and quality-adjusted life years (QALYs). Further, we calculated the maximum price of RSVpreF vaccine within which the program would be cost-effective. In comparison with the current prophylaxis (palivizumab alone), a combined prophylaxis of year-round RSVpreF vaccination of pregnant women and palivizumab prescription for premature infants born in < 32weeks gestational age (wGA) and all infants with high risk prevented 14,382 medically attended cases of RSV (hospitalization, 7490 cases; emergency department, 2239 cases; outpatient, 4653 cases) and 7 deaths, respectively. From a healthcare payer perspective, when the price of RSVpreF vaccine was equal to or less than ¥23,948 (US$182), a combination prophylaxis was cost-effective under the ICER threshold of ¥5million per QALY. The other combination prophylaxis of year-round RSVpreF vaccination and palivizumab prescription of premature born in < 32wGA regardless of risk in infants was a dominant strategy (more effective and less costly). A combined prophylaxis of year-round RSVpreF vaccine and palivizumab could be a cost-effective strategy to protect neonates throughout the infant stage (< 1years old) in Japan.

First real-world data on universal respiratory syncytial virus prophylaxis with Nirsevimab in infants.

Respiratory Syncytial Virus (RSV) predominantly affects young children, with a peak incidence in temperate regions of the northern hemisphere from October to May. Children under 24 months of age are particularly vulnerable because of the immaturity of their lungs and immune systems, often leading to severe respiratory infections. The World Health Organization (WHO) recognizes RSV as a global health priority. Recently, Nirsevimab, a long-acting monoclonal antibody (mAb), was authorised to prevent RSV disease in infants. Our narrative review brings together the effectiveness data of Nirsevimab available in the literature, highlighting the strengths and weaknesses of the published studies and the prevention opportunities represented by the new preparation. All reviewed studies provide evidence for the effectiveness of immunisation with Nirsevimab in real-world settings, beyond the controlled conditions of clinical trials, and highlight its safety and feasibility. Nirsevimab significantly reduces RSV hospitalisations and Intensive Care Unit (ICU) admissions. High coverage and high efficacy of immunisation have been reported, although supply issues and variability in studies present challenges. Continued research and surveillance are critical to understanding the long-term effectiveness of Nirsevimab. Overall, available data provide valuable insights into the efficacy, safety, and impact of immunisation with Nirsevimab in preventing severe RSV infections in infants, highlighting its potential to reduce the burden of RSV-related hospitalisations and improve paediatric health outcomes.

How Does the Burden of Respiratory Syncytial Virus Compare to Influenza in Spanish Adults?

ABSTRACTBackgroundRespiratory syncytial virus (RSV) and influenza infections cause significant annual morbidity and mortality worldwide in at‐risk populations. This study is aimed at assessing hospital burden and healthcare resource utilization (HRU) of RSV and influenza in adults in Spain.MethodsData were obtained from the Projected Hospitalisation Database of inpatient episodes (ages: younger adults 18–50 and 51–64 years; older adults 65–74, 75–84, and ≥ 85 years) during 2015, 2017, and 2018 in Spanish public hospitals. Incidence, mean hospitalization, and HRU assessments, including length of stay (LOS), intensive care unit (ICU) usage, and age‐standardized mortality rates, were collected and stratified by age group, with analyses focusing on the adult population (≥ 18 years old).ResultsMean hospitalization rate in the population across all years was lower in individuals with RSV versus influenza (7.2/100,000 vs. 49.7/100,000 individuals). ICU admissions and median LOS were similar by age group for both viruses. Age‐standardized mortality was 6.3/100,000 individuals and 6.1/100,000 individuals in patients with RSV and influenza, respectively, and mortality rates were similar in older adults (≥ 65 years) for both viruses.ConclusionsRSV and influenza infection were associated with considerable HRU. There is a substantial disease burden for RSV infection in older adults ≥ 65 years. While RSV hospitalization rates in adults reported here appeared lower than influenza, RSV is still underdiagnosed in the hospital setting and its incidence might be similar to, or higher than, influenza.

Respiratory Syncytial Virus (RSV) Hospitalizations in the Elderly in a Tertiary Care Hospital in Southern Italy as a Useful Proxy for Targeting Vaccine Preventive Strategies.

RSV infection causes severe respiratory illness and mortality in the elderly, especially in the presence of comorbidities. Early identification of infection would result in appropriate clinical-therapeutic management, avoiding hospitalizations, the risk of healthcare-associated infections, and inappropriate antibiotic prescriptions, thus reducing healthcare costs and fighting antimicrobial resistance. The aim of this study was to assess RSV hospitalizations in subjects >64 years hospitalized in a large tertiary care hospital in Southern Italy, in order to assess their usefulness as a proxy for targeting a potential vaccination strategy. Fifty-two RSV-positive patients were identified from the 2014-2015 to the 2022-2023 seasons. RSV type B was found in 71.2% of cases. The median age was 78 years (IQR: 72-84) and 40.4% of the subjects had at least one comorbidity; 5.8% needed intensive care. The use of combined rapid tests for SARS-CoV-2/influenza/RSV identification in primary care settings may contribute to an improved definition of the burden of RSV in the elderly. The implementation of an anti-RSV vaccination strategy in the elderly population would reduce direct and indirect infection costs. More robust epidemiological data in Italy are needed for targeted preventive strategies.

Rapid review showed that real-world results on how nirsevimab prevented respiratory syncytial virus hospitalisations were similar to randomised trials.

Rapid review showed that real-world results on how nirsevimab prevented respiratory syncytial virus hospitalisations were similar to randomised trials.

Monoclonal antibody therapies in respiratory syncytial virus prophylaxis-An umbrella review.

The aim was to gather an overview of the evidence of monoclonal antibody therapies in respiratory syncytial virus (RSV) prophylaxis in children. For this umbrella review of previous meta-analyses, we searched PubMed, Scopus, and Web of Science databases in August 2023. We included systematic reviews with meta-analyses of randomized controlled trials. One author extracted the data, and another author validated the data. We extracted all analyses focusing on clinical outcomes and comparing prophylaxis to placebo. Risk of bias in systematic reviews (ROBIS) tool was used to analyze the risk of bias in the included reviews. AMSTAR-2 was used to evaluate the quality of the included reviews. After screening of 323 abstracts and 22 full reports, a total of seven systematic reviews with meta-analyses were included. The risk of bias was rated to be low in four and high in three of these. Three reviews were of moderate quality, one low, and three very low quality according to AMSTAR-2 classification. Six of the meta-analyses were direct comparisons, and one was a network meta-analysis. Five of the reviews focused on palivizumab, one in nirsevimab, and one included all monoclonal antibodies. Six reviews focused on preterm neonates and consisted of 42 comparisons to placebo of which 21 showed efficacy, and 21 had no evidence of a difference. The positive effect was seen in all reviews against RSV infection and RSV hospitalization in palivizumab and nirsevimab groups compared to placebo. None of the mortality comparisons showed efficacy. One meta-analysis focused on cystic fibrosis patients and had eight comparisons, but it was underpowered to detect any results. The overall evidence from previous meta-analyses shows that monoclonal antibodies are effective in preventing RSV infections and RSV hospitalizations in preterm infants. However, no effect on mortality was seen in these studies. Evidence certainty has been ranked mainly from low to moderate.

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

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? 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. 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. 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.

Respiratory syncytial virus in pediatric patients admitted to a tertiary center in Amman: clinical characteristics, and age-related patterns

BackgroundRespiratory syncytial virus (RSV) is a common cause of acute lower respiratory tract infections, particularly in infants and young children during winter. We aimed to study the demographics and clinical characteristics of RSV infections and age-related patterns.MethodsThis retrospective study evaluated pediatric respiratory syncytial virus (RSV) infections conducted in Jordan from September 2021 to March 2022. Patients under the age of five who had viral polymerase chain reaction results showing RSV infection from nasopharyngeal aspiration were included. In addition, demographic information, medical history, and clinical data were gathered. These included comorbidities, outcomes, length of stay, ICU hospitalization, use of antibiotics, and oxygen supplementation.ResultsA total of 199 patients were included. Most patients were males (56.8%) and less than one year (43.7%). Children aged between 1 and 2 years presented with more shortness of breath (90.1%) than infants and children more than two years (66.7% and 87%, respectively) (p < 0.001). Older children (> 2 years) were significantly more likely to use antibiotics and have ICU admission than younger children ≤ 2 years (p = 0.045 and 0.018, respectively). There was no relationship between age groups, recurrent hospitalization, previous RSV infection, oxygen therapy, coinfection, and hospitalization duration. The respiratory rate was higher among patients with co-infection (p = 0.031).ConclusionThe current study provides information on the demographics and clinical characteristics of RSV infections. These findings contribute to a nuanced understanding of RSV infections in the specified population, emphasizing age-specific variations and clinical implications for better management strategies.

Assessment of effectiveness and impact of universal prophylaxis with nirsevimab for prevention of hospitalizations due to respiratory syncytial virus in infants. The NIRSE-GAL study protocol

ABSTRACT Nirsevimab has been recently licensed for universal RSV prophylaxis in infants. NIRSE-GAL is a three-year population-based study initiated in Galicia in September 2023. It aims to evaluate nirsevimab effectiveness against RSV-related hospitalizations lower respiratory tract infections (LRTI), severe RSV, all-cause LRTI, and all-cause hospitalization. NIRSE-GAL also aims to estimate nirsevimab impact on primary healthcare use in the short and mid-term, children’s wheezing and asthma, and medical prescriptions for RSV. The immunization campaigns will be scheduled based on the expected start week for the RSV season and will last the whole season. Immunization will be offered to: i) infants born during the campaign (seasonal), ii) infants < 6 months at the start of the campaign (catch-up), and iii) infants with high-risk factors, aged 6–24 months at the start of the campaign (high-risk). The follow-up period will start: i) the immunization date for all immunized infants, ii) the start of the campaign, for the non-immunized catch-up or high-risk groups, or iii) the birthdate for the non-immunized seasonal group. Infants will be followed up until outcome occurrence, death, or end of study. Nirsevimab effectiveness will be estimated using Poisson and Cox regression models. Sensitivity and stratified analyses will be undertaken. The number of averted cases and the number needed to immunize will be estimated. Immunization failure and nirsevimab safety will be monitored. NIRSE-GAL was approved by the ethics committee of Galicia (CEIC 2023–377) and registered in ClinicalTrials.gov (ID: NCT06180993). Findings will be mainly shared via peer-reviewed publications and scientific conferences.

The Changing Landscape of Respiratory Viruses Contributing to Hospitalizations in Quebec, Canada: Results From an Active Hospital-Based Surveillance Study.

A comprehensive description of the combined effect of SARS-CoV-2 and respiratory viruses other than SARS-CoV-2 (ORVs) on acute respiratory infection (ARI) hospitalizations is lacking. This study aimed to compare the viral etiology of ARI hospitalizations before the pandemic (8 prepandemic influenza seasons, 2012-13 to 2019-20) and during 3 pandemic years (periods of increased SARS-CoV-2 and ORV circulation in 2020-21, 2021-22, and 2022-23) from an active hospital-based surveillance network in Quebec, Canada. We compared the detection of ORVs and SARS-CoV-2 during 3 pandemic years to that in 8 prepandemic influenza seasons among patients hospitalized with ARI who were tested systematically by the same multiplex polymerase chain reaction (PCR) assay during periods of intense respiratory virus (RV) circulation. The proportions of infections between prepandemic and pandemic years were compared by using appropriate statistical tests. During prepandemic influenza seasons, overall RV detection was 92.7% (1384/1493) (respiratory syncytial virus [RSV]: 721/1493, 48.3%; coinfections: 456/1493, 30.5%) in children (<18 years) and 62.8% (2723/4339) (influenza: 1742/4339, 40.1%; coinfections: 264/4339, 6.1%) in adults. Overall RV detection in children was lower during pandemic years but increased from 58.6% (17/29) in 2020-21 (all ORVs; coinfections: 7/29, 24.1%) to 90.3% (308/341) in 2021-22 (ORVs: 278/341, 82%; SARS-CoV-2: 30/341, 8.8%; coinfections: 110/341, 32.3%) and 88.9% (361/406) in 2022-23 (ORVs: 339/406, 84%; SARS-CoV-2: 22/406, 5.4%; coinfections: 128/406, 31.5%). In adults, overall RV detection was also lower during pandemic years but increased from 43.7% (333/762) in 2020-21 (ORVs: 26/762, 3.4%; SARS-CoV-2: 307/762, 40.3%; coinfections: 7/762, 0.9%) to 57.8% (731/1265) in 2021-22 (ORVs: 179/1265, 14.2%; SARS-CoV-2: 552/1265, 43.6%; coinfections: 42/1265, 3.3%) and 50.1% (746/1488) in 2022-23 (ORVs: 409/1488, 27.5%; SARS-CoV-2: 337/1488, 22.6%; coinfections: 36/1488, 2.4%). No influenza or RSV was detected in 2020-21; however, their detection increased in the 2 subsequent years but did not reach prepandemic levels. Compared to the prepandemic period, the peaks of RSV hospitalization shifted in 2021-22 (16 weeks earlier) and 2022-23 (15 weeks earlier). Moreover, the peaks of influenza hospitalization shifted in 2021-22 (17 weeks later) and 2022-23 (4 weeks earlier). Age distribution was different compared to the prepandemic period, especially during the first pandemic year. Significant shifts in viral etiology, seasonality, and age distribution of ARI hospitalizations occurred during the 3 pandemic years. Changes in age distribution observed in our study may reflect modifications in the landscape of circulating RVs and their contribution to ARI hospitalizations. During the pandemic period, SARS-CoV-2 had a low contribution to pediatric ARI hospitalizations, while it was the main contributor to adult ARI hospitalizations during the first 2 seasons and dropped below ORVs during the third pandemic season. Evolving RVs epidemiology underscores the need for increased scrutiny of ARI hospitalization etiology to inform tailored public health recommendations.

Respiratory syncytial virus vaccination during pregnancy for improving infant outcomes.

Respiratory syncytial virus vaccination during pregnancy for improving infant outcomes.