Respiratory Syncytial Virus Hospitalization Research Articles

Estimation of Symptomatic Respiratory Syncytial Virus Infection Incidence in Adults in Multiple Countries: A Time-Series Model-Based Analysis Protocol.

Estimating respiratory syncytial virus (RSV) burden in adults is challenging because of non-specific symptoms, infrequent standard-of-care testing, resolution of viral shedding before seeking medical care, test positivity that varies by specimen site in the upper airway and lower diagnostic test sensitivity compared to children. Conducting prospective observational studies to assess RSV burden in adults is time- and resource-intensive. Thus, model-based approaches can be applied using existing data to obtain more accurate estimates of RSV burden. This protocol establishes essential elements for estimating RSV incidence rate in adults using a time series model-based approach. It can be tailored to specific databases and applied globally across countries, enabling estimation of local RSV disease burden to inform public health decision-making, including immunization policy. Data are analysed using a quasi-Poisson regression model, considering the effect of baseline trends and pathogen co-circulation, stratified by age and risk status. Pathogen co-circulation is represented by viral proxies defined based on ICD code groupings indicating RSV and influenza-specific hospitalizations, lagged 0 up to 4weeks based on the model selection. A final model is constructed in two steps: optimization of the time trend (using p-values) and selection of the viral proxy lag time (using test statistics, to prioritize the most biologically plausible option). The yearly incidence rate and percentage of events attributable to RSV are estimated from the final model. Confidence intervals are calculated using residual bootstrapping. Outcomes to be modelled are based on administrative ICD code groupings and include the number of cardiorespiratory, respiratory and cardiovascular events in a specific care setting (e.g., general practitioner visit, emergency department visit, hospitalization and death). Cardiovascular events are limited to those for which existing evidence suggests an association with RSV infection. Additional secondary outcomes are constructed as a subset of the primary outcomes based on specific ICD code groups.

Respiratory Syncytial Virus-Associated Hospitalizations in Children: A 10-Year Population-Based Analysis in Finland, 2008-2018.

The risk of respiratory syncytial virus (RSV) hospitalization is highest during the first months of life, but few studies have assessed the population-based rates of hospitalization in monthly age groups of infants. We determined the average population-based rates of hospitalization with virologically confirmed RSV infections in children ≤15 years of age admitted during the 10-year period of 2008-2018. Testing for RSV was routine in all children hospitalized with respiratory infections, and all RSV-positive children admitted at any time during the study period were included in the analyses. The annual population-based rate of RSV hospitalization was highest in infants 1 month of age (52.0 per 1000 children; 95% CI, 45.2-59.7), followed by infants <1 month of age (34.8 per 1000; 95% CI, 29.2-41.1) and those 2 months of age (32.2 per 1000; 95% CI, 26.9-38.4). In cumulative age groups, the rate of hospitalization was 39.7 per 1000 (95% CI, 36.2-43.4) among infants <3 months of age, 26.8 per 1000 (95% CI, 24.8-29.0) in infants aged <6 months, and 15.8 per 1000 (95% CI, 14.7-17.0) in those <12 months of age. In monthly age groups of infants, the incidence rates of virologically confirmed RSV hospitalization in all infants up to 3 months of age were substantially higher than those reported in earlier studies. These data may be important for improving the estimates of the cost-effectiveness of various interventions to reduce the burden of RSV in young infants.

The potential public health impact of the respiratory syncytial virus prefusion F protein vaccine in people aged ≥60 years in Japan: results of a Markov model analysis

ABSTRACT Background Respiratory syncytial virus (RSV), a common respiratory pathogen, can lead to severe symptoms, especially in older adults (OA). A recently developed RSV prefusion F protein (RSVPreF3 OA) vaccine confers high protection against RSV lower respiratory tract disease (LRTD) over two full RSV seasons. The aim of this study was to assess the potential public health impact of RSVPreF3 OA vaccination in the Japanese OA population. Research design and methods A static Markov model was used to estimate the number of symptomatic RSV cases, hospitalizations and deaths in the Japanese population aged ≥ 60 years over a 3-year time horizon. Japan-specific RSV epidemiology and healthcare resource use parameters were used; vaccine efficacy was derived from a phase 3 randomized study (AReSVi-006, NCT04886596). Vaccination coverage was set to 50%. Results Without vaccination, >5 million RSV acute respiratory illness (ARI) would occur (2.5 million LRTD and 2.8 million upper respiratory tract infections) leading to ~ 3.5 million outpatient visits, >534,000 hospitalizations and ~ 25,500 RSV-related deaths over 3 years. Vaccination could prevent > 1 million RSV-ARI cases, 728,000 outpatient visits, 143,000 hospitalizations and 6,840 RSV-related deaths. Conclusions RSVPreF3 OA vaccination is projected to have a substantial public health impact by reducing RSV-related morbidity and mortality in the OA population.

Observations of Respiratory Syncytial Virus (RSV) Nucleic Acids in Wastewater Solids Across the United States in the 2022-2023 Season: Relationships with RSV Infection Positivity and Hospitalization Rates.

Respiratory syncytial virus (RSV) is a leading cause of respiratory illness and hospitalization, but clinical surveillance detects only a minority of cases. Wastewater surveillance could determine the onset and extent of RSV circulation in the absence of sensitive case detection, but to date, studies of RSV in wastewater are few. We measured RSV RNA concentrations in wastewater solids from 176 sites during the 2022-2023 RSV season and compared those to publicly available RSV infection positivity and hospitalization rates. Concentrations ranged from undetectable to 107 copies per gram. RSV RNA concentration aggregated at state and national levels correlated with infection positivity and hospitalization rates. RSV season onset was determined using both wastewater and clinical positivity rates using independent algorithms for 14 states where both data were available at the start of the RSV season. In 4 of 14 states, wastewater and clinical surveillance identified RSV season onset during the same week; in 3 states, wastewater onset preceded clinical onset, and in 7 states, wastewater onset occurred after clinical onset. Wastewater concentrations generally peaked in the same week as hospitalization rates but after case positivity rates peaked. Differences in onset and peaks in wastewater versus clinical data may reflect inherent differences in the surveillance approaches.

Cost-Effectiveness of Respiratory Syncytial Virus Vaccines for Adults

&#x0D; Three economic evaluations and 1 summary of economic evaluations were identified that assessed the cost-effectiveness of 2 respiratory syncytial virus (RSV) vaccines of interest (RSVPreF3 [Arexvy] and RSVpreF [Abrysvo]) compared with no intervention in older adults residing in high-income countries. No economic evaluations assessing mRNA-1345 were identified. No publications investigating RSV vaccination in adults aged 59 years or younger were identified.&#x0D; &#x0D; In total, 5 economic evaluations for RSV vaccines in adults were identified.&#x0D; Four economic evaluations were conducted in the US and 1 was conducted in Hong Kong. All results were presented in terms of incremental cost-utility ratios (i.e., incremental cost per quality-adjusted life-years gained). Net cost per outcome averted was reported for 1 economic evaluation, and cost per hospitalization averted was reported for 3 economic evaluations.&#x0D; The results of all publications found that RSVPreF3 (Arexvy) and RSVpreF (Abrysvo) were more costly and more effective than no intervention for RSV-associated disease. All publications reported that vaccinating older adults against RSV disease was potentially cost-effective. All publications noted that the cost-effectiveness was dependent on vaccine cost, vaccine efficacy, the waning of vaccine protection, RSV hospitalization incidence, health care unit costs, and respective regional willingness-to-pay thresholds.&#x0D; &#x0D; &#x0D; The generalizability of the identified economic evaluations may be limited because the study settings were notably different from Canada. To estimate the cost-effectiveness of RSV vaccinations in Canada, a de novo economic evaluation conducted from a Canadian setting comparing RSVPreF3 (Arexvy), RSVpreF (Abrysvo), and mRNA-1345 is required.&#x0D;

Population-based Influenza and Respiratory Syncytial Virus Hospitalizations and In-hospital Mortality Rates Among Mexican Children Less Than Five Years of Age.

Population-based information regarding the impact of respiratory syncytial virus (RSV) and influenza on hospital admissions and mortality is scant for many countries. Prospective testing of RSV and influenza virus was undertaken in patients <5 years old admitted to hospital with acute respiratory infection (ARI) between July, 2014 and June, 2015, and mortality rates for children living in 3 municipalities in the state of San Luis Potosí were calculated. During the 12-month study period, 790 children living in these municipalities were admitted with ARI. RSV was detected in 245 (31%) and influenza in 47 (5.9%). History of preterm birth was recorded for 112 children on admission. For children <5 years old, ARI-, RSV- and influenza-associated admission rates were 23.2, 7.2 and 1.4 (per 1000 population), respectively. The corresponding admission rates per 1000 infants <1 year old were 78, 25.2 and 4.4. Preterm infant admission rates were 2 times higher than those of term infants. Six children died; RSV was detected in 4 (66.6%) of the deceased, while no deaths were associated with influenza. ARI and RSV in-hospital mortality rates for children <5 years were 0.18 and 0.12 per 1000 population. ARI and RSV mortality rates in preterm infants were 7 and 14 times higher than in term infants, respectively. RSV was associated with both high admission and in-hospital mortality rates in children <5 years old. Specific interventions, such as active or passive immunization, to prevent RSV infections are required to reduce ARI-associated infant mortality.

Association between age of respiratory syncytial virus infection hospitalization and childhood asthma: A systematic review.

Identifying child age of RSV infection associated with increased risk of asthma is important for developing asthma prevention strategies. Our systematic review aimed to comprehensively summarize studies of the association between age of RSV infection and childhood asthma risk. The study protocol was pre-registered, and our study report adhered to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA). Inclusion criteria were prospective and retrospective cohort studies and case-control studies which assessed the association of age of RSV infection before age 2 years and risk of childhood asthma after age two years. Relevant studies were identified through MEDLINE, Embase, Cochrane and International Clinical Trials Registry Platform (ICTRP) from study inception through May 5, 2023. Studies were evaluated with the Quality In Prognosis Studies (QUIPS) tool. From 149 studies screened, five studies (two prospective cohort studies and three retrospective cohort studies) were included in our systematic review, including 47,603 participants. Available studies only assessed age of severe RSV infection and asthma risk. The included studies used different age categories and outcome definitions, and were rated as having high risk of bias. Two studies had sample sizes of less than 300 and did not provide conclusive results related to age of RSV hospitalization and asthma risk. The other three studies reported RSV hospitalization between age 6 months and 23 months compared with age 0-6 months being associated with a higher odds ratio, hazard ratio, or incidence rate ratio of asthma diagnosis/hospitalization. Due to the heterogeneous epidemiological designs, including exposures and outcome ascertainments of the included studies, we could not perform a meta-analysis, or calculate weighted averages of the effect estimates. Our systematic review highlights a major gap in our knowledge about the relationship between age of RSV infection and asthma risk.

Cost of illness due to respiratory syncytial virus acute lower respiratory tract infection among infants hospitalized in Argentina

BackgroundInformation is scarce regarding the economic burden of respiratory syncytial virus (RSV) disease in low-resource settings. This study aimed to estimate the cost per episode of hospital admissions due to RSV severe disease in Argentina.MethodsThis is a prospective cohort study that collected information regarding 256 infants under 12 months of age with acute lower respiratory tract infection (ALRTI) due to RSV in two public hospitals of Buenos Aires between 2014 and 2016. Information on healthcare resource use was collected from the patient’s report and its associated costs were estimated based on the financial database and account records of the hospitals. We estimated the total cost per hospitalization due to RSV using the health system perspective. The costs were estimated in US dollars as of December 2022 (1 US dollar = 170 Argentine pesos).ResultsThe mean costs per RSV hospitalization in infants was US$587.79 (95% confidence interval [CI] $535.24 – $640.33). The mean costs associated with pediatric intensive care unit (PICU) admission more than doubled from those at regular pediatric wards ($1,556.81 [95% CI $512.21 – $2,601.40] versus $556.53 [95% CI $514.59 – $598.48]).ConclusionsThis study shows the direct economic impact of acute severe RSV infection on the public health system in Argentina. The estimates obtained from this study could be used to inform cost-effectiveness analyses of new preventive RSV interventions being developed.

Saudi Initiative of Bronchiolitis Diagnosis, Management, and Prevention 2024 updated consensus on the prevention of respiratory syncytial virus.

Respiratory syncytial virus (RSV) is the major cause of bronchiolitis among children under 5 years of age worldwide, accounting for a prevalence of 25%-88% in Saudi Arabia. Although no effective treatment for the virus exists, passive immunoprophylaxis reduced RSV hospitalizations in high-risk children. With recent advances in immunization, the Saudi Initiative of Bronchiolitis Diagnosis, Management, and Prevention panel screened recent relevant international guidelines, locally published data, and expert consensus to update guidelines for RSV prevention, taking into consideration the resources, timing, varying health profiles, and RSV burden in Saudi Arabia. The panel updated its recommendations to include immunization of infants, mothers, and older adults. Practical guidelines were prepared to facilitate the administration of the short-acting and newly developed long-acting RSV monoclonal antibodies (mAb) during the regular follow-ups of high-risk infants in specialized clinics. In addition, long-acting mAb was highlighted as all-infant protection in the routine immunization calendar.

Characteristics and Outcomes of Pregnant Women Hospitalized With Laboratory-Confirmed Respiratory Syncytial Virus Before and During the COVID-19 Pandemic.

Respiratory syncytial virus (RSV) can cause severe disease among infants and older adults. Less is known about RSV among pregnant women. To analyze hospitalizations with laboratory-confirmed RSV among women aged 18 to 49 years, we used data from the RSV Hospitalization Surveillance Network (RSV-NET), a multistate population-based surveillance system. Specifically, we compared characteristics and outcomes among (1) pregnant and nonpregnant women during the pre-COVID-19 pandemic period (2014-2018), (2) pregnant women with respiratory symptoms during the prepandemic and pandemic periods (2021-2023), and (3) pregnant women with and without respiratory symptoms in the pandemic period. Using multivariable logistic regression, we examined whether pregnancy was a risk factor for severe outcomes (intensive care unit admission or in-hospital death) among women aged 18 to 49 years who were hospitalized with RSV prepandemic. Prepandemic, 387 women aged 18 to 49 years were hospitalized with RSV. Of those, 350 (90.4%) had respiratory symptoms, among whom 33 (9.4%) were pregnant. Five (15.2%) pregnant women and 74 (23.3%) nonpregnant women were admitted to the intensive care unit; no pregnant women and 5 (1.6%) nonpregnant women died. Among 279 hospitalized pregnant women, 41 were identified prepandemic and 238 during the pandemic: 80.5% and 35.3% had respiratory symptoms, respectively (P < .001). Pregnant women were more likely to deliver during their RSV-associated hospitalization during the pandemic vs the prepandemic period (73.1% vs 43.9%, P < .001). Few pregnant women had severe RSV disease, and pregnancy was not a risk factor for a severe outcome. More asymptomatic pregnant women were identified during the pandemic, likely due to changes in testing practices for RSV.

Birth characteristics as predictors of respiratory syncytial virus hospitalisation in newborns to optimise immunisation schedule.

To examine birth characteristics that influence infant respiratory syncytial virus (RSV) hospitalisation risk in order to identify risk factors for severe RSV infections. Retrospective cohort study of 460 771 Sicilian children under 6 months old from January 2007 to December 2017. Hospital discharge records were consulted to identify cases and hospitalisations with International Classification of Diseases, Ninth Revision, Clinical Modification codes 466.11 (RSV bronchiolitis), 480.1 (RSV pneumonia) and 079.6 (RSV). RSV hospitalisation risk was estimated using adjusted odds ratios (aOR) and 95% confidence intervals (95% CI). Overall, 2420 (5.25 per 1000 infants) RSV-related hospitalisations were identified during the study, with girls accounting for 52.8%. RSV hospitalisation risk increased for full-term, transferred, extreme immature, and preterm neonates with serious issues (aOR 3.25, 95% CI 2.90-3.64; aOR 1.86, 95% CI 1.47-2.32; aOR 1.54, 95% CI 1.11-2.07; and aOR 1.48, 95% CI 1.14-1.90). Compared to children born in June, the risk of RSV hospitalisation was significantly higher in children born in January (aOR 28.09, 95% CI 17.68-48.24) and December (aOR 27.36, 95% CI 17.21-46.99). This study identified birth month and diagnosis-related groups as key predictors of RSV hospitalisations. This could help manage monoclonal antibody appropriateness criteria.

Clinical, Genomic, and Immunological Characterization of RSV Surge in Sydney, Australia, 2022.

The 2022 seasonal respiratory syncytial virus (RSV) epidemic in Sydney, Australia saw an unprecedented number of RSV detections. We aimed to characterize genomic and immunologic factors associated with the surge in RSV cases. Whole genome sequences of RSV were generated from 264 RSV-infected infants and linked to case-matched clinical data from the 2022 southern hemisphere RSV season. We then performed an immunologic analysis of baseline RSV-specific humoral immunity in women of childbearing age before and throughout the coronavirus disease 2019 pandemic. Clinical analysis revealed a high burden of disease across patients of all health backgrounds. More than one-half of RSV-related health care visits by infants resulted in hospitalization, and one-quarter required high-flow respiratory support or a higher level of care. Viral phylogenetic analyses revealed that 2022 Sydney RSV sequences were closely related to viruses that had been circulating globally since 2017, including those detected in recent US outbreaks. Nonsynonymous mutations within the palivizumab and nirsevimab binding sites were detected at low frequencies. There was no difference in baseline RSV-neutralizing antibody titers between 2020 and 2022. Collectively, these findings suggest that neither the emergence of a novel RSV genotype nor hypothesized immune debt was associated with the surge of RSV cases and hospitalizations in 2022. Continued genomic and immunologic surveillance is required to further understand the factors driving outbreaks of RSV globally, and to inform guidelines for the rollout and ongoing use of recently developed immunotherapeutics and vaccines.

Respiratory Syncytial Virus-related Lower Respiratory Tract Infections in Neonatal and Post-neonatal Babies: A Series of Four Cases

Respiratory Syncytial Virus (RSV) is a highly contagious seasonal virus that is the leading cause of acute Lower Respiratory Tract Infections (LRTI) in the paediatric age group and is one of the leading causes of death in children under five in developing countries. There is evidence that severe RSV infection and hospitalisation in early life increase the risk of recurrent wheezing, childhood asthma, and allergic sensitisation. Even though RSV being a major global health concern, very few papers concentrate on the neonatal period in India. The present case series presents four cases (three females and one male baby) highlighting the impact of RSV in neonatal and post-neonatal infants in India. The cases highlight the diversity of presentation; one infant required prolonged High-flow Nasal Cannula (HFNC) support, while two needed just symptomatic care. The importance of Polymerase Chain Reaction (PCR) in resource-constrained situations is highlighted as diagnostic issues are examined. Treatment focuses on supportive care; oxygen and respiratory support are provided in more severe cases. The present study emphasises the need for early detection and preventative measures, such as using novel treatments like nirsevimab. The present case series advocates for focused therapies and additional research in the Indian paediatric environment, adding insightful perspectives to the expanding body of knowledge on RSV.

The Impact of COVID-19 Pandemic on Respiratory Syncytial Virus Infection in Children.

Background/Objective: Respiratory syncytial virus (RSV) is a major cause of bronchiolitis in infants and young children. Bronchiolitis, an acute inflammation of the lower respiratory tract, can lead to pneumonia, respiratory failure, and death. We aimed to compare the incidence and severity of RSV infection in children aged 0-60 months before and during the coronavirus disease 2019 (COVID-19) pandemic. Methods: A retrospective chart review was conducted on patients aged 0-60 months who tested positive for RSV between May 1, 2018, and May 31, 2022, in a community hospital in Queens County, New York City, United States. Comparisons were made between seasons 2018-2019 and 2019-2020 as before, and seasons 2020-2021 and 2021-2022 as during the COVID-19 pandemic. Severity of RSV infection was assessed using the Bronchiolitis Severity Score (BSS). Data were analyzed using R software, a p value of < 0.05 was considered statistically significant. Results: The incidence of RSV infection in seasons 2018-2019 and 2019-2020 peaked from mid-October to February, whereas the first season during the COVID-19 pandemic (2020-2021) was truncated with a very low incidence of RSV infection, and season 2021-2022 peaked from September to January, with the highest incidence (37%) and lower frequency of RSV infection at any given point. Patients during the season 2021-2022 were older (H [2, 196.6] = 12.5, p < 0.001, 95% CI = [5.4, 25.6]) and had milder illness (H [2, 187.5] = 7.5, p < 0.01, 95% CI = [2.1, 19.2]). Conclusions: We observed a lower incidence of RSV infection and a lower rate of hospitalization for RSV during the COVID-19 pandemic. The second RSV season during the COVID-19 pandemic began earlier, lasted longer, and had a lower frequency. Older children with milder illnesses were affected most during this season. RSV epidemiology and disease burden were impacted by the COVID-19 pandemic and could have significant ramifications for its prevention and control strategies.

Nirsevimab for Prevention of Hospitalizations Due to RSV in Infants

BackgroundThe safety of the monoclonal antibody nirsevimab and the effect of nirsevimab on hospitalizations for respiratory syncytial virus (RSV)–associated lower respiratory tract infection when administered in healthy infants are unclear.MethodsIn a pragmatic trial, we randomly assigned, in a 1:1 ratio, infants who were 12 months of age or younger, had been born at a gestational age of at least 29 weeks, and were entering their first RSV season in France, Germany, or the United Kingdom to receive either a single intramuscular injection of nirsevimab or standard care (no intervention) before or during the RSV season. The primary end point was hospitalization for RSV-associated lower respiratory tract infection, defined as hospital admission and an RSV-positive test result. A key secondary end point was very severe RSV-associated lower respiratory tract infection, defined as hospitalization for RSV-associated lower respiratory tract infection with an oxygen saturation of less than 90% and the need for supplemental oxygen.ResultsA total of 8058 infants were randomly assigned to receive nirsevimab (4037 infants) or standard care (4021 infants). Eleven infants (0.3%) in the nirsevimab group and 60 (1.5%) in the standard-care group were hospitalized for RSV-associated lower respiratory tract infection, which corresponded to a nirsevimab efficacy of 83.2% (95% confidence interval [CI], 67.8 to 92.0; P<0.001). Very severe RSV-associated lower respiratory tract infection occurred in 5 infants (0.1%) in the nirsevimab group and in 19 (0.5%) in the standard-care group, which represented a nirsevimab efficacy of 75.7% (95% CI, 32.8 to 92.9; P=0.004). The efficacy of nirsevimab against hospitalization for RSV-associated lower respiratory tract infection was 89.6% (adjusted 95% CI, 58.8 to 98.7; multiplicity-adjusted P<0.001) in France, 74.2% (adjusted 95% CI, 27.9 to 92.5; multiplicity-adjusted P=0.006) in Germany, and 83.4% (adjusted 95% CI, 34.3 to 97.6; multiplicity-adjusted P=0.003) in the United Kingdom. Treatment-related adverse events occurred in 86 infants (2.1%) in the nirsevimab group.ConclusionsNirsevimab protected infants against hospitalization for RSV-associated lower respiratory tract infection and against very severe RSV-associated lower respiratory tract infection in conditions that approximated real-world settings. (Funded by Sanofi and AstraZeneca; HARMONIE ClinicalTrials.gov number, NCT05437510).

Respiratory syncytial virus disease morbidity in Australian infants aged 0 to 6 months: a systematic review with narrative synthesis

BackgroundA significant proportion of the global respiratory syncytial virus (RSV) associated morbidity is accounted for by infants aged 0 to 6 months, who are particularly vulnerable to severe disease. In 2015, 44% of global hospitalisations in infants in this age group were secondary to RSV. The objective of this systematic review is to appraise and synthesise the local evidence of RSV infection morbidity among Australian infants aged 0 to 6 months and to assess the implications for future immunisation strategies.MethodsElectronic databases (Medline, Embase, Pubmed and Global Health) were searched for full-text articles published between 2000 and 2023 in English language. Studies that examined markers of RSV disease morbidity in infants aged 0 to 6 months in Australia who had laboratory confirmed RSV infection were eligible for inclusion. The outcomes of interest were incidence, prevalence, testing rate, positivity rate, mortality, emergency department visits, community health visits, hospitalisation, intensive care unit admission, supplementary oxygen use, mechanical ventilation, risk factors for disease severity and monoclonal antibody use.ResultsThe database search identified 469 studies. After removal of duplicates and full-text review, 17 articles were eligible for inclusion. This review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Synthesis without meta-analysis guidelines.ConclusionsQualitative analysis of the included studies showed that Australian infants aged 0 to 6 months have higher rates of RSV testing, positivity and incidence; and more likely to develop severe disease that requires hospitalisation, intensive care unit admission or respiratory support, compared to children and adults of all ages. Aboriginal and Torres Strait Islander infants aged 0 to 6 months demonstrated higher rates of RSV infection and hospitalisation, compared to non-Indigenous infants. Age-related trends persisted in geographic areas with varying seasonal transmission of RSV, and during the SARS-CoV-2 pandemic. Passive immunisation strategies targeting infants in their first 6 months of life, either via vaccination of pregnant women or administration of long-acting monoclonal antibody during infancy, could effectively reduce RSV disease burden in Australia.

EPH13 RSV Hospitalizations’ Burden in New-Born Patients and Potential Impact of Maternal Vaccination: A French Analysis

EPH13 RSV Hospitalizations’ Burden in New-Born Patients and Potential Impact of Maternal Vaccination: A French Analysis

The rapidly changing landscape of respiratory syncytial virus prophylaxis.

The introduction of nirsevimab (a respiratory syncytial virus [RSV] monoclonal antibody that can protect for minimum 5 months with a single dose) and RSV maternal vaccines to protect young infants has the potential to dramatically decrease RSV hospitalizations in Canada. However, there remain many unanswered questions before optimal use of these products can be assured.

2650. Characteristics of In-Hospital Care and Immediate Post-Discharge Care Status among Older Adults Hospitalized with Respiratory Syncytial Virus Infection, Seasonal Influenza, Acute Myocardial Infarction, and Stroke in the US

Abstract Background Despite increased recognition of the morbidity, mortality, and economic burden of respiratory syncytial virus (RSV) in adults, few studies have documented the status of post-discharge care after RSV hospitalization. This study assessed in-hospital and immediate post-discharge care status in older adults hospitalized with RSV in the US and compared it with other serious medical conditions (influenza, acute myocardial infarction (AMI), and stroke) that have long-standing disease prevention efforts. Methods This retrospective cohort study used data from Premier Healthcare Database between January 1, 2015, to December 31, 2019. Adults aged ≥ 65 years hospitalized due to primary diagnosis of RSV, influenza, AMI, or stroke were included. Discharge statuses were used to categorize the levels of immediate post-discharge care as shown in Figure 1. Descriptive statistics and Sankey diagrams were used to summarize the four cohorts. Results Overall, 2,559 RSV, 174,826 influenza, 208,448 AMI, and 274,102 stroke hospitalizations were identified with similar mean patient ages of 79.8, 76.8, 76.3, and 78.0 years, respectively. Almost all patients ( &amp;gt; 90%) had underlying comorbidities. The mean inpatient length of stay (LOS) was similar in the four cohorts (4.0, 4.4, 3.7, and 4.1 days, respectively), but the prevalence of mechanical ventilator use varied, i.e., 0.4%, 13.7%, 5.9%, and 1.4%, respectively. Intensive Care Unit (ICU) admissions during RSV hospitalizations were infrequent (3.0%) as compared to influenza (16.8%), AMI (24.5%), and stroke (20.5%). The mean ICU LOS for these four cohorts were 2.3, 2.8, 1.7, and 1.7 days in the same order. Immediately following discharge, moderate care was required for 23.9%, 22.9%, 14.1%, and 17.5% of RSV, influenza, AMI, and stroke hospitalizations, respectively. Elevated care was considerably more frequent for stroke hospitalizations (48.1%) than RSV (18.8%), influenza (21.4%), and AMI (19.3%) hospitalizations (Figure 2). Conclusion Older adults discharged from RSV hospitalizations require considerable care with needs comparable to influenza and AMI discharges. Given the substantial care requirements of RSV hospitalizations in older adults, focus on disease prevention efforts for RSV are needed. Disclosures Reiko Sato, PhD, Pfizer Inc: employee|Pfizer Inc: Stocks/Bonds Jennifer Judy, MS, PhD, Pfizer: Stocks/Bonds Kari Yacisin, M.D., Pfizer: Employee|Pfizer: Stocks/Bonds Elizabeth Begier, M.D., M.P.H., Pfizer: EB is an employee of Pfizer, the sponsor of this study|Pfizer: Stocks/Bonds Poorva Sardana, MSc, Pfizer Inc: Contracted Research Neha Agrawal, MA, Pfizer Inc: Contracted Research Anchita Goswami, MSc, Pfizer Inc: Contracted Research Manvi Sharma, RPh, MBA, PhD, Pfizer Inc: Contracted Research

1636. Prevention of respiratory syncytial virus hospitalizations (RSVH) in US infants who paid through Medicaid would have a disproportionate benefit for Black, Hispanic, Asian/Pacific Islander, Native American and Other race/ethnicity infants, and have a substantial impact on overall RSVH burden and related costs: Rates of respiratory syncytial virus hospitalization (RSVH) among US infants by race/ethnicity and insurance payer, NIS 2018-2020

Abstract Background Respiratory syncytial virus (RSV) is the leading cause of US infant hospitalization [1]. The objective of this work is to describe the rate of US infant RSV hospitalization (RSVH) and related charges by race/ethnicity and type of insurance payer. Methods Using the US national Healthcare Cost and Utilization Project (HCUP) National Inpatient Sample (NIS) for 2018-2020, we identified US infant RSVH and charges by RSV diagnosis in any position, race and Hispanic origin of the mother (race/ethnicity), and type of insurance payer. Results RSVH Rates and Burden: Rates of US infant RSVH are highest among Native American infants, are similar for White, Black, and Hispanic infants, and are lower among Other/Unknown and Asian/Pacific Islander infants. The trend of RSVH rates being higher among infants covered by Medicaid is consistent across each race/ethnicity group (Figure 1). This results in a greater proportion of the US infant RSVH burden among Black, Hispanic, Asian/Pacific Islander, Native American, and Other/Unknown infants being among infants covered by Medicaid (Figure 2). Overall, 60% of US infant RSVH is among those covered by Medicaid. RSVH Charges: For White, Black, Native American and Other/Unknown race/ethnicity infants, mean RSVH total charges are higher for Medicaid insurance (Figure 3), despite Medicaid reimbursing at lower levels. For Hispanic and Asian/Pacific Islander race/ethnicity infants the opposite is true, charges are higher for infants with other/unknown insurance (Figure 3). This results in a greater proportion of the US infant RSVH total charges among all infants except White infants being among infants that pay with Medicaid (Figure 4). Overall, 63% of RSVH total charges is among infants that pay with Medicaid (Figure 4). Conclusion The prevention of RSVH in US infants covered by Medicaid would have a disproportionate benefit for Black, Hispanic, Asian/Pacific Islander, Native American and Other/Unknown race/ethnicity infants and contribute towards economic and race/ethnicity equity. Because 60% of US infant RSVHs are covered by Medicaid accounting for 63% of RSVH total charges, the prevention of RSVH among infants who paid through Medicaid would also have a substantial impact on overall RSVH burden and related costs. Disclosures Christopher B. Nelson, PhD MPH, Sanofi: employee|Sanofi: employee|Sanofi: Stocks/Bonds|Sanofi: Stocks/Bonds Xiaohui Jiang, MS, Sanofi: Grant/Research Support Mina Suh, MPH, International Health, AstraZeneca: Grant/Research Support|Sanofi: Grant/Research Support|Sobi: Grant/Research Support Jon Fryzek, PhD, MPH, Sanofi: Grant/Research Support