Severe Morbidity and Mortality Associated With Respiratory Syncytial Virus Versus Influenza Infection in Hospitalized Older Adults

Respiratory syncytial virus: challenges in diagnosis and impact on the elderly: Recommendations from a multidisciplinary panel

Respiratory syncytial virus (RSV) is an important cause of respiratory illness. While most attention is paid to childhood infection, the RSV burden in adults ≥60 y should also be considered. In Brazil, this is generally underrecognized, where greater focus is toward other respiratory pathogens. This article presents insights from a multidisciplinary panel gathered to review epidemiologic data and current diagnostic approaches to RSV in Brazil (and their limitations) and develop communication strategies to improve knowledge and awareness. National surveillance data indicate a steady increase in cases of RSV-related severe acute respiratory illness (RSV-SARI) in those aged ≥60 y in recent years, with high fatality rates (>30%). Routine RSV testing in older individuals with respiratory symptoms is relatively low. Educational activities targeted toward health-care professionals and the general public are critical to raising awareness of the importance of RSV in older individuals, particularly as protective vaccines are now available.

Respiratory syncytial virus knowledge, attitudes, and perceptions among adults in the United States

Respiratory syncytial virus (RSV) is associated with considerable morbidity and mortality among older adults (aged ≥60 years) and adults with certain chronic conditions in the United States (US). Despite this burden, no previous studies have assessed the knowledge, attitudes, and perceptions (KAP) of RSV among these populations. This study evaluates RSV-related KAP among US adults at increased risk of severe RSV infection. A cross-sectional, web-based survey was administered from May to June 2022 to better understand respiratory infection- and RSV-related KAP among US adults who are at risk of severe RSV infection. The survey included ≥200 adults in each of 4 subgroups: adults aged 60-89 years, and adults aged 18-59 years with ≥1 chronic cardiovascular condition, chronic pulmonary condition, or diabetes mellitus. Survey responses were analyzed descriptively overall and by subgroup, with exploratory logistic regression modeling used to evaluate characteristics associated with RSV awareness and concern. Among the 827 survey respondents, only 43.3% had ever heard of RSV (n = 358/827). The study identified key knowledge gaps (e.g. bacterial vs. viral nature of respiratory infections, RSV seasonality, common RSV symptoms, extent to which RSV causes respiratory infections in specific patient populations). Although 33.7% of RSV-aware adults (n = 120/356) reported being worried/very worried about RSV, 67.3% (n = 241/358) rarely consider RSV as a potential cause of their cold/flu-like symptoms. Results from this study highlight important knowledge gaps related to RSV, perceived risk, and severity of RSV. Findings can be used to support the development of tailored education efforts to support RSV prevention.

Infectious Disease Updates for Primary Care

This article summarizes the situation with public health threats for primary care patients as of early 2024 and provides updates on strategies for the prevention, diagnosis, and treatment of common infections where new treatments and vaccines are available. For flu and COVID, an update on treatment is also provided-along with pearls useful for the busy primary care provider. The authors also discuss a new treatment option for drug-resistant vulvovaginal candidiasis and provide a balanced view of the increasingly popular technique of preventing bacterial sexually transmitted infections using doxycycline after condomless sex among men who have sex with men.

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

INTRODUCTION

We aimed to describe the risk profile of respiratory syncytial virus (RSV) infections among adults ≥ 60 years in Valladolid from January 2010 to August 2022, and to compare them with influenza and COVID-19 controls.

METHODS

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 < 30 days) and compared severity between RSV patients vs. influenza and COVID-19 controls using multivariable logistic regression models.

RESULTS

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 (adjusted OR 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.

CONCLUSIONS

RSV especially affects those with comorbidities, coinfections, and living in care institutions. RSV vaccination could have an important public health impact in this population.

Antibody responses to respiratory syncytial virus: a population-based cross-sectional serological study in Southern China, 2021

OBJECTIVES

With remarkable progress in the field of respiratory syncytial virus (RSV) prophylaxis, it is critical to understand population immunity against RSV. We aim to describe the RSV pre-F IgG antibodies across all age groups in Southern China and to evaluate the risk factors associated with lower antibody levels.

METHODS

We performed a community-based cross-sectional sero-epidemiological study in Anhua County, Hunan Province, Southern China, from July 15, 2021, to November 5, 2021. Serum samples were tested for IgG antibodies against the RSV prefusion F (pre-F) protein using an enzyme-linked immunosorbent assay. We estimated the geometric mean titres (GMTs) and seropositivity rates across all age groups. The generalized linear models were built to identify factors associated with antibody levels.

RESULTS

A total of 890 participants aged 4 months to older than 89 years were enrolled. The lowest RSV pre-F IgG GMTs were observed in infants and toddlers aged 4 months to younger than 2 years (3.0; 95% CI, 2.6-3.5). With increasing age, the RSV pre-F IgG GMT increased to 4.3 (95% CI, 4.1-4.4) between the ages of 2 and younger than 5 years and then stabilized at high levels throughout life. All the children had serological evidence of RSV infection by the age of 5 years. Age was associated with RSV pre-F antibody levels in children, with an estimated 1.9-fold (95% CI, 0.8-3.6) increase in titre per year before 5 years of age, although it was not significantly associated with antibody levels in adults aged older than 60 years.

DISCUSSION

Our findings could provide a comprehensive understanding of the gaps in RSV immunity at the population level and inform the prioritization of immunization platforms.

Cold-adapted influenza vaccine carrying three repeats of a respiratory syncytial virus (RSV) fusion glycoprotein epitope site protects BALB/c mice and cotton rats against RSV infection

Respiratory syncytial virus is the major cause of respiratory viral infections, particularly in infants, immunocompromised populations, and the elderly (over 65 years old), the prevention of RSV infection has become a priority. In this study, we generated a chimeric influenza virus, termed LAIV/RSV/HA-3F, using reverse genetics technology which contained three repeats of the RSV fusion protein neutralizing epitope site II to the N terminal in the background of the hemagglutinin (HA) gene of cold adapted influenza vaccine A/California/7/2009 ca. LAIV/RSV/HA-3F exhibited cold-adapted (ca) and attenuated (att) phenotype. BALB/c mice immunized intranasally with LAIV/RSV/HA-3F showed robust immunogenicity, inducing viral-specific antibody responses against both influenza and RSV, eliciting RSV-specific humoral, cellular and mucosal immune responses. LAIV/RSV/HA-3F also conferred protection as indicated by reduced viral titers and improved lung histopathological alterations against live RSV virus challenge. Mechanismly, single-cell RNA sequencing (scRNA-seq) and single-cell T cell antigen receptor (TCR) sequencing were employed to characterize the immune responses triggered by chimeric RSV vaccine, displaying that LAIV/RSV/HA-3F provided protection mainly via interferon-γ (IFN-γ). Moreover, we found that LAIV/RSV/HA-3F significantly inhibited viral replication in the challenged lung and protected against subsequent RSV challenge in cotton rats without causing lung disease. Taken together, our findings demonstrated that LAIV/RSV/HA-3F has potential as a promising bivalent vaccine with dual purpose candidate for the prevention of influenza and RSV, and preclinical and clinical studies warrant further investigations.

Burden of respiratory syncytial virus (RSV) infection in Germany: a systematic review

BACKGROUND

Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory infection and hospitalizations among infants, young children, and the elderly. This systematic literature review aimed to summarize the epidemiological and economic burden estimates of RSV infection at any age in Germany.

METHODS

We conducted a systematic literature search to identify full-text articles published from 2003 to 2023 and reporting data on the epidemiological or economic burden of RSV in Germany. Based on pre-specified eligibility criteria, data on incidence, rates of hospital and intensive care unit (ICU) admission, clinical manifestation, underlying conditions, seasonality, health care resource use and costs were extracted.

RESULTS

After screening 315 full-text articles, we included 42 articles in the review. The characteristics of the included studies were heterogenous regarding study population, setting, age groups and RSV-related outcome measures. The most frequently reported epidemiological outcome measures were RSV detection rate (n = 33), followed by clinical manifestation (n = 19), seasonality (n = 18), and underlying conditions of RSV infection (n = 13). RSV detection rates were reported across heterogenous study populations, ranging from 5.2 to 55.4% in pediatric inpatient cases and from 2.9 to 14% in adult inpatient cases. All articles that reported RSV detection rates across several age groups demonstrated the highest burden in infants and young children. Few articles reported RSV-related outcome measures distinctively for the outpatient setting. Health care resource use, such as hospital length of stay, ICU admission rate and treatment of patients with RSV infection were described in 23 articles, of which only one study quantified associated costs from 1999 to 2003 for children ≤ 3 years. In-hospital ICU admission rates varied between 3.6 and 45%, depending on population characteristics as age and underlying conditions.

CONCLUSIONS

This systematic review revealed that RSV imposes substantial disease burden in infants, young children, and the elderly in Germany, whereby infants are particularly affected. To date, there has been limited exploration of the impact of RSV infection on healthy children or the elderly in Germany. Given their notably high reported burden in studies, the medical and economic RSV burden in these groups should move more into focus.

The Annual Economic Burden of Respiratory Syncytial Virus in Adults in the United States

BACKGROUND

Current estimates of the economic burden of respiratory syncytial virus (RSV) are needed for policymakers to evaluate adult RSV vaccination strategies.

METHODS

A cost-of-illness model was developed to estimate the annual societal burden of RSV in US adults aged ≥60 years. Additional analyses were conducted to estimate the burden of hospitalized RSV in all adults aged 50-59 years and in adults aged 18-49 years with potential RSV risk factors.

RESULTS

Among US adults aged ≥60 years, the model estimated 4.0 million annual RSV cases (95% uncertainty interval [UI], 2.7-5.6 million) and an annual economic burden of $6.6 billion (95% UI, $3.1-$12.9 billion; direct medical costs, $2.9 billion; indirect costs, $3.7 billion). The 4% of RSV cases that were hospitalized contributed to 94% of direct medical costs. Additional analyses estimated $422 million in annual hospitalization costs among all adults aged 50-59 years. Among adults aged 18-49 years with RSV risk factors, annual per capita burden was highest among people with congestive heart failure at $51 100 per 1000 people.

DISCUSSION

The economic burden of RSV is substantial among adults aged ≥50 years and among adults aged 18-49 years with RSV risk factors, underscoring the need for preventive interventions for these populations.

Burden of respiratory syncytial virus in older adults in Taiwan: An expert perspective on knowledge gaps

The burden of respiratory syncytial virus (RSV) infection among older adults in Taiwan is not well understood due to a scarcity of published epidemiological data. Nonetheless, the increasing proportion of older adults is anticipated to translate to increased burden of RSV infection, presenting a challenge to the healthcare system. Thus, an expert meeting was convened among a panel of infectious disease specialists from Taiwan to evaluate the existing local evidence and data gaps related to RSV infection in older adults (aged ≥50 years), and propose steps to generating evidence on disease burden among this population. Overall, there are few studies on the clinical and economic burden of RSV infection in Taiwan, and existing data are limited by small sample sizes and highly selected populations. Inconsistent RSV testing practices among older adults contribute to under-diagnosis and under-reporting, driven by limitations to reimbursement policies that discourage proactive RSV testing in older adults, and the lack of appropriate, targeted RSV treatment. Crucially, the paucity of epidemiological data may perpetuate a lack of awareness of RSV among clinicians and the public, hinder investments into RSV testing at a policymaker level, and thereby impede implementation of consistent diagnostic practices, precluding a deeper understanding of RSV. To overcome these challenges, it is imperative to prioritize generation of epidemiological data to establish the burden of RSV infection among older adults in Taiwan. Such data would also support a multi-stakeholder group in assessing the impact of future RSV-related interventions, such as educational initiatives and preventative strategies including vaccines.

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

Background

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.

Methods

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.

Results

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).

Conclusions

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.

Patients With Inflammatory Bowel Disease Are at Increased Risk of Hospitalization Due to Respiratory Syncytial Virus

INTRODUCTION

Patients with inflammatory bowel disease (IBD) are at increased risk of developing respiratory infections. Respiratory syncytial virus (RSV) is a common respiratory virus with adverse outcomes in older adults. This study aimed to determine whether patients with IBD are at increased risk of a serious infection due to RSV.

METHODS

We conducted a retrospective study using the multi-institutional research network TriNetX to assess the risk of hospitalization in a cohort of patients with IBD compared with that in a non-IBD control cohort with RSV infection from January 1, 2007, to February 27, 2023. One-to-one (1:1) propensity score matching was performed for demographic variables and RSV risk factors between the 2 cohorts. Risk was expressed as adjusted odds ratio (aOR) with 95% confidence interval (CI).

RESULTS

There were 794 patients in the IBD-RSV cohort and 93,074 patients in the non-IBD-RSV cohort. The mean age of the IBD-RSV cohort was 55.6 ± 20 years, 59% were female, 80% were White, and 56.9% had Crohn's disease. The IBD-RSV cohort was at an increased risk of hospitalization (aOR 1.30, 95% CI 1.06-1.59). There was no difference in the risk (aOR 0.83, 95% CI 0.58-1.19) of a composite outcome of hospitalization-related complications between the 2 cohorts. Recent systemic corticosteroid use (<3 months) was associated with an increased risk of hospitalization (aOR 1.86, 95% CI 1.30-2.59) in the IBD-RSV cohort.

DISCUSSION

We found that adult patients with IBD and RSV infection are at an increased risk of hospitalization and may benefit from the new RSV vaccine recommended for adults aged 60 years and older.

Immunogenicity and Safety Following 1 Dose of AS01E-Adjuvanted Respiratory Syncytial Virus Prefusion F Protein Vaccine in Older Adults: A Phase 3 Trial

BACKGROUND

The recently approved AS01E-adjuvanted respiratory syncytial virus (RSV) prefusion F protein-based vaccine for older adults (RSVPreF3 OA) demonstrated high efficacy against RSV-related disease in ≥60-year-olds.

METHODS

This ongoing phase 3 study in ≥60-year-olds evaluates immune persistence until 3 years after RSVPreF3 OA vaccination. Here, we describe interim results on humoral and cell-mediated immunogenicity, reactogenicity, and safety until 1 year post-dose 1.

RESULTS

In total, 1653 participants were vaccinated. One month post-dose 1, neutralization titers increased 10.5-fold (RSV-A) and 7.8-fold (RSV-B) vs pre-dose 1. Titers then declined to levels 4.4-fold (RSV-A) and 3.5-fold (RSV-B) above pre-dose 1 at month 6 and remained 3.1-fold (RSV-A) and 2.3-fold (RSV-B) above pre-dose 1 levels after 1 year. RSVPreF3-binding immunoglobulin G levels and CD4+ T-cell frequencies showed similar kinetics. Solicited administration-site and systemic adverse events (mostly mild to moderate and transient) were reported by 62.2% and 49.5% of participants. Serious adverse events were reported by 3.9% of participants within 6 months post-dose 1; 1 case was considered vaccine related.

CONCLUSIONS

One RSVPreF3 OA dose elicited cell-mediated and RSV-A- and RSV-B-specific humoral immune responses that declined over time but remained above pre-dose 1 levels for at least 1 year. The vaccine was well tolerated with an acceptable safety profile. Clinical Trials Registration. NCT04732871 (ClinicalTrials.gov).

Human metapneumovirus infection is associated with a substantial morbidity and mortality burden in adult inpatients

Background

Human metapneumovirus (hMPV) is one of the leading respiratory viruses. This prospective observational study aimed to describe the clinical features and the outcomes of hMPV-associated lower respiratory tract infections in adult inpatients.

Methods

Consecutive adult patients admitted to one of the 31 participating centers with an acute lower respiratory tract infection and a respiratory multiplex PCR positive for hMPV were included. A primary composite end point of complicated course (hospital death and/or the need for invasive mechanical ventilation) was used.

Results

Between March 2018 and May 2019, 208 patients were included. The median age was 74 [62-84] years. Ninety-seven (47 %) patients were men, 187 (90 %) had at least one coexisting illness, and 67 (31 %) were immunocompromised. Median time between first symptoms and hospital admission was 3 [2-7] days. The two most frequent symptoms were dyspnea (86 %) and cough (85 %). The three most frequent clinical diagnoses were pneumonia (42 %), acute bronchitis (20 %) and acute exacerbation of chronic obstructive pulmonary disease (16 %). Among the 52 (25 %) patients who had a lung CT-scan, the most frequent abnormality was ground glass opacity (41 %). While over four-fifths of patients (81 %) received empirical antibiotic therapy, a bacterial coinfection was diagnosed in 61 (29 %) patients. Mixed flora (16 %) and enterobacteria (5 %) were the predominant documentations. The composite criterion of complicated course was assessable in 202 (97 %) patients, and present in 37 (18 %) of them. In the subpopulation of pneumonia patients (42 %), we observed a more complicated course in those with a bacterial coinfection (8/24, 33 %) as compared to those without (5/60, 8 %) (p = 0.02). Sixty (29 %) patients were admitted to the intensive care unit. Among them, 23 (38 %) patients required invasive mechanical ventilation. In multivariable analysis, tachycardia and alteration of consciousness were identified as risk factors for complicated course.

Conclusion

hMPV-associated lower respiratory tract infections in adult inpatients mostly involved elderly people with pre-existing conditions. Bacterial coinfection was present in nearly 30 % of the patients. The need for mechanical ventilation and/or the hospital death were observed in almost 20 % of the patients.

Respiratory Syncytial Virus Sequelae Among Adults in High-Income Countries: A Systematic Literature Review and Meta-analysis

INTRODUCTION

Respiratory syncytial virus (RSV) can cause severe respiratory infections in adults; however, information on associated sequelae is limited. This systematic literature review aimed to identify sequelae in adults within 1 year following RSV-related hospitalization or resolution of acute infection.

METHODS

Studies were identified from Embase, MEDLINE, LILACS, SciELO, and grey literature. Random-effects meta-analyses using restricted maximum likelihood were used to calculate the proportions and relative risks of sequelae in patients with RSV compared with controls (patients with RSV-negative influenza-like illness, influenza, and parainfluenza) per follow-up period, population, and treatment setting, where possible.

RESULTS

Twenty-one relevant studies covering the period from 1990 to 2019 were included. Among the general population, the most frequent clinical sequela was sustained function loss (33.5% [95% CI 27.6-39.9]). Decline in lung function and cardiovascular event or congestive heart failure were also identified. Utilization sequelae were readmission (highest at > 6 months after discharge) and placement in a skilled nursing facility. The only subpopulation with data regarding sequelae was transplant patients. Among lung transplant patients, the most frequently reported clinical sequelae were decline in lung function, followed by graft dysfunction and bronchiolitis obliterans syndrome. Pooled relative risks were calculated for the following sequela with controls (primarily influenza-positive patients): cardiovascular event (general population) and pulmonary impairment (hematogenic-transplant patients) both 1.4 (95% CI 1.0-2.0) and for readmission (general population) 1.2 (95% CI 1.1-1.3).

CONCLUSIONS

Although less data are available for RSV than for influenza or other lower respiratory tract infections, RSV infection among adults is associated with medically important sequelae, with a prevalence similar to other respiratory pathogens. RSV sequelae should be included in disease burden estimates.

Clinical characteristics and outcomes of respiratory syncytial virus-associated ARF in immunocompetent patients: A seven-year experience at a tertiary hospital in France

BACKGROUND

Respiratory syncytial virus (RSV) is widely recognized as a cause of acute respiratory failure in infants and immunocompromised patients. However, RSV can also contribute to acute respiratory failure in adults, particularly among the elderly population. The objective of this study was to analyze the clinical characteristics and outcomes of immunocompetent adults hospitalized for RSV infection.

METHODS

This retrospective study included all immunocompetent adult patients consecutively admitted to a tertiary care hospital with RSV-related acute respiratory failure over a seven-year period (2016-2023). Diagnosis of RSV infection was made through nasal swabs or pulmonary samples, with multiplex reverse transcription polymerase chain reaction (RT-PCR). Patients were eligible for inclusion if they required supplemental oxygen therapy for at least 48 h.

RESULTS

One hundred and four patients met the inclusion criteria. Median age [IQR] was 77 years [67-85]. Ninety-seven patients had at least one comorbidity (97/104, 93%). At the time of RSV diagnosis, 67 patients (67/104, 64%) experienced acute decompensation of a pre-existing chronic comorbidity. Antibiotics were started in 80% (77/104) of patients; however, only 16 patients had a confirmed diagnosis of bacterial superinfection. Twenty-six patients needed ventilatory support (26/104, 25%) and 21 were admitted to the intensive care unit (21/104, 20%). The median duration of oxygen therapy [IQR] was 6 days [3-9], while the median hospital length of stay [IQR] was 11 days [6-15]. The overall mortality rate within 1 month of hospital admission was 13% (14/104). The sole variables associated with one-month mortality were age and maximum oxygen flow during hospitalization.

CONCLUSION

RSV-associated acute respiratory failure affected elderly individuals with multiple comorbidities and was associated with prolonged hospitalization and a high mortality rate.

Model correction of diagnostic coding-based RSV incidence for children 0-4 years in the US

BACKGROUND

Although administrative claims data have a high degree of completeness, not all medically attended Respiratory Syncytial Virus-associated lower respiratory tract infections (RSV-LRTIs) are tested or coded for their causative agent. We sought to determine the attribution of RSV to LRTI in claims data via modeling of temporal changes in LRTI rates against surveillance data.

METHODS

We estimated the weekly incidence of LRTI (inpatient, outpatient, and total) for children 0-4 years using 2011-2019 commercial insurance claims, stratified by HHS region, matched to the corresponding weekly NREVSS RSV and influenza positivity data for each region, and modelled against RSV, influenza positivity rates, and harmonic functions of time assuming negative binomial distribution. LRTI events attributable to RSV were estimated as predicted events from the full model minus predicted events with RSV positivity rate set to 0.

RESULTS

Approximately 42% of predicted RSV cases were coded in claims data. Across all regions, the percentage of LRTI attributable to RSV were 15-43%, 10-31%, and 10-31% of inpatient, outpatient, and combined settings, respectively. However, when compared to coded inpatient RSV-LRTI, 9 of 10 regions had improbable corrected inpatient LRTI estimates (predicted RSV/coded RSV ratio < 1). Sensitivity analysis based on separate models for PCR and antigen-based positivity showed similar results.

CONCLUSIONS

Underestimation based on coding in claims data may be addressed by NREVSS-based adjustment of claims-based RSV incidence. However, where setting-specific positivity rates is unavailable, we recommend modeling across settings to mirror NREVSS's positivity rates which are similarly aggregated, to avoid inaccurate adjustments.

Respiratory Syncytial Virus Vaccination in the Adult Pulmonary Patient

TOPIC IMPORTANCE

Since its discovery in 1957, respiratory syncytial virus (RSV) has been widely recognized as a common and deadly pathogen. Although early studies focused on the impact of RSV on the health of children, more recent data show that RSV imposes a significant burden on individuals aged ≥ 70 years. RSV also substantially harms the health of individuals with cardiopulmonary diseases.

REVIEW FINDINGS

Early efforts to develop an RSV vaccine were hampered by toxicity due to antibody-enhanced viral pneumonia and a lack of efficacy in vaccines that targeted the postfusion configuration of the F fusion protein, which is crucial to the pathogenesis of RSV-mediated injury. A newer wave of vaccines has targeted a stabilized prefusion F protein, generating effective neutralizing antibodies and reducing the burden of mild and severe RSV lower respiratory tract injury. This review focuses on the burden of RSV in patients with pulmonary diseases, highlights the tumultuous path from the early days of RSV vaccine development to the modern era, and offers insights into key gaps in knowledge that must be addressed to adequately protect the vulnerable population of patients with severe pulmonary diseases.

SUMMARY

RSV vaccination with bivalent RSVPreF or RSVPreF3OA, which target the stabilized prefusion F protein, can be broadly recommended to adults with pulmonary diseases aged ≥ 60 years. However, more data are needed to understand how these vaccinations affect key clinical outcomes in individuals with pulmonary disease.

Electronic Health Record-Based Algorithm for Monitoring Respiratory Virus-Like Illness

Viral respiratory illness surveillance has traditionally focused on single pathogens (e.g., influenza) and required fever to identify influenza-like illness (ILI). We developed an automated system applying both laboratory test and syndrome criteria to electronic health records from 3 practice groups in Massachusetts, USA, to monitor trends in respiratory viral-like illness (RAVIOLI) across multiple pathogens. We identified RAVIOLI syndrome using diagnosis codes associated with respiratory viral testing or positive respiratory viral assays or fever. After retrospectively applying RAVIOLI criteria to electronic health records, we observed annual winter peaks during 2015-2019, predominantly caused by influenza, followed by cyclic peaks corresponding to SARS-CoV-2 surges during 2020-2024, spikes in RSV in mid-2021 and late 2022, and recrudescent influenza in late 2022 and 2023. RAVIOLI rates were higher and fluctuations more pronounced compared with traditional ILI surveillance. RAVIOLI broadens the scope, granularity, sensitivity, and specificity of respiratory viral illness surveillance compared with traditional ILI surveillance.

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.

Safety and Immunogenicity of Bivalent RSVpreF Vaccine Coadministered With Seasonal Inactivated Influenza Vaccine in Older Adults

BACKGROUND

Respiratory syncytial virus (RSV) and influenza are both typically seasonal diseases, with winter peaks in temperate climates. Coadministration of an RSV vaccine and influenza vaccine could be a benefit, requiring 1 rather than 2 visits to a healthcare provider for individuals receiving both vaccines.

METHODS

The primary immunogenicity objective of this phase 3, 1:1 randomized, double-blind, placebo-controlled study in healthy adults aged ≥65 years in Australia was to demonstrate noninferiority of immune responses with coadministration of the stabilized RSV prefusion F protein-based vaccine (RSVpreF) and seasonal inactivated influenza vaccine (SIIV) versus SIIV or RSVpreF administered alone, using a 1.5-fold noninferiority margin (lower bound 95% confidence interval >.667). Safety and tolerability were evaluated by collecting reactogenicity and adverse event data.

RESULTS

Of 1403 participants randomized, 1399 received vaccinations (median age, 70; range, 65‒91 years). Local reactions and systemic events were mostly mild or moderate when RSVpreF was coadministered with SIIV or administered alone. No vaccine-related serious adverse events were reported. Geometric mean ratios were 0.86 for RSV-A and 0.85 for RSV-B neutralizing titers at 1 month after RSVpreF administration and 0.77 to 0.90 for strain-specific hemagglutination inhibition assay titers at 1 month after SIIV. All comparisons achieved the prespecified 1.5-fold noninferiority margin.

CONCLUSIONS

The primary study objectives were met, demonstrating noninferiority of RSVpreF and SIIV immune responses when RSVpreF was coadministered with SIIV and that RSVpreF had an acceptable safety and tolerability profile when coadministered with SIIV. The results of this study support coadministration of RSVpreF and SIIV in an older-adult population.

CLINICAL TRIALS REGISTRATION

https://clinicaltrials.gov/study/NCT05301322.

Cost-effectiveness of Prefusion F Protein-based Vaccines Against Respiratory Syncytial Virus Disease for Older Adults in the United States

BACKGROUND

Two prefusion F protein-based vaccines, Arexvy and Abrysvo, have been authorized by the US Food and Drug Administration for protecting older adults against respiratory syncytial virus (RSV)-associated lower respiratory tract illness. We evaluated the health benefits and cost-effectiveness of these vaccines.

METHODS

We developed a discrete-event simulation model, parameterized with the burden of RSV disease including outpatient care, hospitalization, and death for adults aged 60 years or older in the United States. Taking into account the costs associated with these RSV-related outcomes, we calculated the net monetary benefit using quality-adjusted life-year (QALY) gained as a measure of effectiveness and determined the range of price-per-dose (PPD) for Arexvy and Abrysvo vaccination programs to be cost-effective from a societal perspective.

RESULTS

Using a willingness-to-pay of $95 000 per QALY gained, we found that vaccination programs could be cost-effective for a PPD up to $127 with Arexvy and $118 with Abrysvo over the first RSV season. Achieving an influenza-like vaccination coverage of 66% for the population of older adults in the United States, the budget impact of these programs at the maximum PPD ranged from $6.48 to $6.78 billion. If the benefits of vaccination extend to a second RSV season as reported in clinical trials, we estimated a maximum PPD of $235 for Arexvy and $245 for Abrysvo, with 2-year budget impacts of $11.78 and $12.25 billion, respectively.

CONCLUSIONS

Vaccination of older adults would provide substantial direct health benefits by reducing outcomes associated with RSV-related illness in this population.

Respiratory Syncytial Virus Hospitalizations Associated With Social Vulnerability by Census Tract: An Opportunity for Intervention?

Background

Respiratory syncytial virus (RSV) can cause hospitalization in young children and older adults. With vaccines and monoclonal antibody prophylaxis increasingly available, identifying social factors associated with severe illnesses can guide mitigation efforts.

Methods

Using data collected by the RSV Hospitalization Surveillance Network from 2016 to 2023, we identified RSV hospitalizations in Tennessee. We linked hospitalization information (eg, patient demographic characteristics and outcome) with population-level variables (eg, social vulnerability and health care insurance coverage) from publicly available data sets using census tract of residence. Hospitalization incidence was calculated and stratified by period (2016-2020 and 2020-2023). We modeled social vulnerability effect on hospitalization incidence using Poisson regression.

Results

Among 2687 RSV hospitalizations, there were 677 (25.2%) intensive care unit admissions and 38 (1.4%) deaths. The highest RSV hospitalization incidences occurred among children aged <5 years and adults aged ≥65 years: 272.8 per 100 000 person-years (95% CI, 258.6-287.0) and 60.6 (95% CI, 56.0-65.2), respectively. Having public health insurance was associated with higher hospitalization incidence as compared with not having public insurance: 60.5 per 100 000 person-years (95% CI, 57.6-63.4) vs 14.3 (95% CI, 13.4-15.2). Higher hospitalization incidence was associated with residing in a census tract in the most socially vulnerable quartile vs the least vulnerable quartile after adjusting for age, sex, and period (incidence rate ratio, 1.4; 95% CI, 1.3-1.6).

Conclusions

RSV hospitalization was associated with living in more socially vulnerable census tracts. Population measures of social vulnerability might help guide mitigation strategies, including vaccine and monoclonal antibody promotion and provision to reduce RSV hospitalization.

Melatonin improves influenza virus infection-induced acute exacerbation of COPD by suppressing macrophage M1 polarization and apoptosis

BACKGROUND

Influenza A viruses (IAV) are extremely common respiratory viruses for the acute exacerbation of chronic obstructive pulmonary disease (AECOPD), in which IAV infection may further evoke abnormal macrophage polarization, amplify cytokine storms. Melatonin exerts potential effects of anti-inflammation and anti-IAV infection, while its effects on IAV infection-induced AECOPD are poorly understood.

METHODS

COPD mice models were established through cigarette smoke exposure for consecutive 24 weeks, evaluated by the detection of lung function. AECOPD mice models were established through the intratracheal atomization of influenza A/H3N2 stocks in COPD mice, and were injected intraperitoneally with melatonin (Mel). Then, The polarization of alveolar macrophages (AMs) was assayed by flow cytometry of bronchoalveolar lavage (BAL) cells. In vitro, the effects of melatonin on macrophage polarization were analyzed in IAV-infected Cigarette smoking extract (CSE)-stimulated Raw264.7 macrophages. Moreover, the roles of the melatonin receptors (MTs) in regulating macrophage polarization and apoptosis were determined using MTs antagonist luzindole.

RESULTS

The present results demonstrated that IAV/H3N2 infection deteriorated lung function (reduced FEV20,50/FVC), exacerbated lung damages in COPD mice with higher dual polarization of AMs. Melatonin therapy improved airflow limitation and lung damages of AECOPD mice by decreasing IAV nucleoprotein (IAV-NP) protein levels and the M1 polarization of pulmonary macrophages. Furthermore, in CSE-stimulated Raw264.7 cells, IAV infection further promoted the dual polarization of macrophages accompanied with decreased MT1 expression. Melatonin decreased STAT1 phosphorylation, the levels of M1 markers and IAV-NP via MTs reflected by the addition of luzindole. Recombinant IL-1β attenuated the inhibitory effects of melatonin on IAV infection and STAT1-driven M1 polarization, while its converting enzyme inhibitor VX765 potentiated the inhibitory effects of melatonin on them. Moreover, melatonin inhibited IAV infection-induced apoptosis by suppressing IL-1β/STAT1 signaling via MTs.

CONCLUSIONS

These findings suggested that melatonin inhibited IAV infection, improved lung function and lung damages of AECOPD via suppressing IL-1β/STAT1-driven macrophage M1 polarization and apoptosis in a MTs-dependent manner. Melatonin may be considered as a potential therapeutic agent for influenza virus infection-induced AECOPD.

Predictors of prolonged length of stay in adult patients with respiratory syncytial virus infections - a multi-center historical cohort study

Objectives

Several studies have reported risk factors for severe disease and mortality in hospitalized adults with RSV infections. There is limited information available regarding the factors that affect the duration of a patient's hospital length of stay (LOS).

Methods

This was a multicenter historical cohort study of adult patients hospitalized for laboratory-confirmed RSV in Southeast Michigan between January 2017 and December 2021. Hospitalized patients were identified using the International Classification of Diseases, Tenth Revision 10 codes for RSV infection. Mean LOS was computed; prolonged LOS was defined as greater than the mean.

Results

We included 360 patients with a mean age (SD) of 69.9 ± 14.7 years, 63.6% (229) were female and 63.3% (228) of white race. The mean hospital LOS was 7.1 ± 5.4 days. Factors associated with prolonged LOS in univariable analysis were old age, body mass index (BMI), smoking status, Charlson Weighted Index of Comorbidity (CWIC), home oxygen, abnormal chest x-ray (CXR), presence of sepsis, use of oxygen, and antibiotics at the time of presentation. Predictors for prolonged LOS on admission in multivariable analysis were age on admission (p < 0.001), smoking status (p = 0.001), CWIC (p = 0.038) and abnormal CXR (p = 0.043).

Interpretation

Our study found that age on admission, smoking history, higher CWIC and abnormal CXR on admission were significantly associated with prolonged LOS among adult patients hospitalized with RSV infection. These findings highlight the significance of promptly recognizing and implementing early interventions to mitigate the duration of hospitalization for adult patients suffering from RSV infection.

Severity of Respiratory Syncytial Virus vs COVID-19 and Influenza Among Hospitalized US Adults

Importance

On June 21, 2023, the Centers for Disease Control and Prevention recommended the first respiratory syncytial virus (RSV) vaccines for adults aged 60 years and older using shared clinical decision-making. Understanding the severity of RSV disease in adults can help guide this clinical decision-making.

Objective

To describe disease severity among adults hospitalized with RSV and compare it with the severity of COVID-19 and influenza disease by vaccination status.

Design, Setting, and Participants

In this cohort study, adults aged 18 years and older admitted to the hospital with acute respiratory illness and laboratory-confirmed RSV, SARS-CoV-2, or influenza infection were prospectively enrolled from 25 hospitals in 20 US states from February 1, 2022, to May 31, 2023. Clinical data during each patient's hospitalization were collected using standardized forms. Data were analyzed from August to October 2023.

Exposures

RSV, SARS-CoV-2, or influenza infection.

Main Outcomes and Measures

Using multivariable logistic regression, severity of RSV disease was compared with COVID-19 and influenza severity, by COVID-19 and influenza vaccination status, for a range of clinical outcomes, including the composite of invasive mechanical ventilation (IMV) and in-hospital death.

Results

Of 7998 adults (median [IQR] age, 67 [54-78] years; 4047 [50.6%] female) included, 484 (6.1%) were hospitalized with RSV, 6422 (80.3%) were hospitalized with COVID-19, and 1092 (13.7%) were hospitalized with influenza. Among patients with RSV, 58 (12.0%) experienced IMV or death, compared with 201 of 1422 unvaccinated patients with COVID-19 (14.1%) and 458 of 5000 vaccinated patients with COVID-19 (9.2%), as well as 72 of 699 unvaccinated patients with influenza (10.3%) and 20 of 393 vaccinated patients with influenza (5.1%). In adjusted analyses, the odds of IMV or in-hospital death were not significantly different among patients hospitalized with RSV and unvaccinated patients hospitalized with COVID-19 (adjusted odds ratio [aOR], 0.82; 95% CI, 0.59-1.13; P = .22) or influenza (aOR, 1.20; 95% CI, 0.82-1.76; P = .35); however, the odds of IMV or death were significantly higher among patients hospitalized with RSV compared with vaccinated patients hospitalized with COVID-19 (aOR, 1.38; 95% CI, 1.02-1.86; P = .03) or influenza disease (aOR, 2.81; 95% CI, 1.62-4.86; P < .001).

Conclusions and Relevance

Among adults hospitalized in this US cohort during the 16 months before the first RSV vaccine recommendations, RSV disease was less common but similar in severity compared with COVID-19 or influenza disease among unvaccinated patients and more severe than COVID-19 or influenza disease among vaccinated patients for the most serious outcomes of IMV or death.

Public Health Impact of the Adjuvanted RSVPreF3 Vaccine for Respiratory Syncytial Virus Prevention Among Older Adults in the United States

INTRODUCTION

Respiratory syncytial virus (RSV) is an important cause of lower respiratory tract disease in older adults, resulting in substantial morbidity and mortality.

METHODS

This study estimates the public health impact of vaccination with the adjuvanted RSVPreF3 vaccine among adults aged ≥ 60 years in the United States (US). A static, multi-cohort Markov model was used to estimate RSV-related outcomes over a 3-year time horizon for scenarios with and without one-time RSV vaccination. The base-case analysis assumed the same vaccination coverage as for influenza vaccines, with key epidemiology and vaccine inputs obtained from the published literature and phase 3 clinical trial results for the adjuvanted RSVPreF3 vaccine. Model outcomes included the clinical burden of RSV (symptomatic RSV acute respiratory illness [RSV-ARI] cases [classified as upper or lower respiratory tract disease], pneumonia complications, and mortality) and RSV-related healthcare resource use (hospitalizations, emergency department visits, outpatient visits, and antibiotic prescriptions).

RESULTS

In the base-case analysis, approximately 56.7 million adults aged ≥ 60 years received the vaccine, resulting in 2,954,465 fewer symptomatic RSV-ARI cases over 3 years compared with no vaccination, including 321,019 fewer X-ray confirmed pneumonia cases and 16,660 fewer RSV-related deaths. Vaccination also prevented a substantial number of RSV-related hospitalizations (203,891), emergency department visits (164,060), outpatient visits (1,577,586), and antibiotic prescriptions (1,343,915) over the 3-year period. A considerable public health impact was observed across a range of sensitivity analyses.

CONCLUSIONS

These findings highlight the potential of the adjuvanted RSVPreF3 vaccine to substantially reduce RSV disease burden among US older adults aged ≥ 60 years.

Respiratory syncytial virus-related hospital stays in adults in France from 2012 to 2021: A national hospital database study

BACKGROUND

Respiratory syncytial virus (RSV) causes lower respiratory tract infections (LRTI) that may lead to hospitalization or death. The present study aimed to assess the burden of RSV infections in hospitalized adults.

METHODS

RSV-related hospitalizations were identified from the nationwide hospital claims database in France (PMSI) from 2012 to 2021 using ICD-10 codes J12.1, J20.5, J21.0 or B97.4, and outcomes assessment focused on 2016-2020. In-hospital outcomes included length of stay, need for intensive care (ICU) and in-hospital all-cause mortality. Post-discharge outcomes included 30-day readmission for decompensation, 90-day RSV-related readmission, and 30 and 60-day in-hospital mortality.

RESULTS

A cumulated number of 17 483 RSV-related stays were identified representing a rate of 72.0 cases per million stays. The outcomes assessment included 12,987 patients: 55.8 % were females and the mean age was 74.1 ± 16.4 years, with 57 % ≥ 75 years. Most of patients (78.6 %) had at least one comorbidity, mainly chronic respiratory (56.3 %) and cardiovascular diseases (41.3 %), or diabetes (23.5 %). A co-infection was found in 22.4 %, primarily bacterial (12 %). The mean length of stay was 12.3 ± 13.1 days. Overall, 10.9 % were admitted to an ICU and in-hospital mortality was 7.3 %. In-hospital outcomes were higher in cases of co-infection. Among 12 033 patients alive at discharge from the index stay, 6.5 % were readmitted with RSV within 90 days, 8.1 % for decompensation within 30 days, and 5.6 % died within 60-day.

CONCLUSION

This study demonstrated the high burden of RSV infections in older adults and those with chronic conditions, and the need for preventive strategies.

From Forgotten Pathogen to Target for New Vaccines: What Clinicians Need to Know about Respiratory Syncytial Virus Infection in Older Adults

Respiratory syncytial virus (RSV) is increasingly recognized as being implicated in acute illness in older adults, with a significant weight in hospitalizations for respiratory illness and death. By means of a best-evidence review, this paper aims to investigate whether RSV can be considered a forgotten pathogen in older patients, looking at trends in the literature volume and exploring possible epidemiological and clinical features underlying the focus given to it. We then present an assessment of its disease burden and present and future strategies for its reduction, particularly in light of the recent availability of new vaccines.

Prevalence of Respiratory Viral Infections in Deceased Persons during the COVID-19 Pandemic Season 2021-2022: A Population-Based Observational Study

Although the omicron variant of SARS-CoV-2 circulated intensely during the 2021-2022 season, many patients with severe acute respiratory disease tested negative for COVID-19. The aim of this study was to assess the presence of different respiratory viruses in deceased persons. The proportion of deceased persons with respiratory viral infections in the 2021-2022 season in Navarre, Spain, was estimated considering all deaths caused by confirmed COVID-19 according to the epidemiological surveillance and the results of multiplex PCR tests for respiratory viruses performed in a sample of deceased persons with a cause of death other than COVID-19. Of 3578 deaths, 324 (9.1%) were initially reported as caused by pre-mortem confirmed COVID-19. A sample of 242 persons who died by causes other than COVID-19 were tested post-mortem; 64 (26.4%) of them were positive for any respiratory virus: 11.2% for SARS-CoV-2, 5.8% for rhinovirus, 3.7% for human coronavirus, 2.5% for metapneumovirus, 1.7% for respiratory syncytial virus, 1.7% for parainfluenza, 1.2% for influenza, and less than 1% each for adenovirus and bocavirus. Combining both approaches, we estimated that 34.4% of all deceased persons during the study period had a respiratory viral infection and 19.2% had SARS-CoV-2. Only 33.3% (9/27) of SARS-CoV-2 and 5.0% (2/40) of other viruses detected post-mortem had previously been confirmed pre-mortem. In a period with very intense circulation of SARS-CoV-2 during the pandemic, other respiratory viruses were also frequently present in deceased persons. Some SARS-CoV-2 infections and most other viral infections were not diagnosed pre-mortem. Several respiratory viruses may contribute to excess mortality in winter.

Comparison of mortality and outcomes of four respiratory viruses in the intensive care unit: a multicenter retrospective study

This retrospective study aimed to compare the mortality and burden of respiratory syncytial virus (RSV group), SARS-CoV-2 (COVID-19 group), non-H1N1 (Seasonal influenza group) and H1N1 influenza (H1N1 group) in adult patients admitted to intensive care unit (ICU) with respiratory failure. A total of 807 patients were included. Mortality was compared between the four following groups: RSV, COVID-19, seasonal influenza, and H1N1 groups. Patients in the RSV group had significantly more comorbidities than the other patients. At admission, patients in the COVID-19 group were significantly less severe than the others according to the simplified acute physiology score-2 (SAPS-II) and sepsis-related organ failure assessment (SOFA) scores. Using competing risk regression, COVID-19 (sHR = 1.61; 95% CI 1.10; 2.36) and H1N1 (sHR = 1.87; 95% CI 1.20; 2.93) were associated with a statistically significant higher mortality while seasonal influenza was not (sHR = 0.93; 95% CI 0.65; 1.31), when compared to RSV. Despite occurring in more severe patients, RSV and seasonal influenza group appear to be associated with a more favorable outcome than COVID-19 and H1N1 groups.

Understanding the Burden of Respiratory Syncytial Virus in Older Adults in Latin America: An Expert Perspective on Knowledge Gaps

Respiratory syncytial virus (RSV) is a significant global health concern and major cause of hospitalization, particularly among infants and older adults. The clinical impact of RSV is well characterized in infants; however, in many countries, the burden and risk of RSV in older populations are overlooked. In Latin America, there are limited data on RSV epidemiology and disease management in older adults. Therefore, the impact of RSV in this region needs to be addressed. Here, current insights on RSV infections in older populations in Latin America, including those with underlying health conditions, are discussed. We also outline the key challenges limiting our understanding of the burden of RSV in Latin America in a worldwide context and propose an expert consensus to improve our understanding of the burden of RSV in the region. By so doing, we aim to ultimately improve disease management and outcomes of those at risk and to alleviate the impact on healthcare systems.A graphical plain language summary is available with this article.

Resurgence of human respiratory syncytial virus during COVID-19 pandemic in Southern Brazil

Respiratory Syncytial Virus (RSV) is an important cause of respiratory infection in humans. Severe cases are common in children ≤2 years old, immunocompromised individuals, and the elderly. In 2020, RSV infection reduced in Rio Grande do Sul (RS), southern Brazil; however, in 2021 resurgence of RSV was observed. This study analyzed epidemiological and genetic features of RSV infection cases reported in 2021 in RS. Nasopharyngeal samples collected from individuals with respiratory infection negative for SARS-CoV-2, Influenza A and B viruses were assessed for the presence of RSV by real time RT-qPCR. RSV-A and RSV-B genomic sequencing and phylogenetic reconstructions were performed for genotyping and clade characterization. Among 21,035 respiratory samples analyzed, 2,947 were positive for RSV, 947 of which were hospitalized patients. Positive cases were detected year-round, with the highest number in June-July (winter). Children <1 year comprised 56.28% (n = 533) of the hospitalized patients infected with RSV, whereas 14.46% (n = 137) were individuals >60 years. Of a total of 361 deaths, 14.68% (n = 53) were RSV positive, mostly patients >60 years old (73.58%, n = 39). Chronic kidney disease, cardiopathy, Down syndrome and neurological diseases were associated with RSV infection. RSV-A was identified in 58.5% (n = 117/200) of the patients, and RSV-B in 41.5% (n = 83/200). Of 95 RSV genomes recovered from SARI cases, 66 were RSV-A GA.2.3.5 genotype, while 29 were RSV-B GB.5.0.5a genotype. This study provides epidemiological and molecular data on RSV cases in RS during the COVID-19 pandemic and highlights that investigation of different respiratory viruses is essential for decision-making and disease prevention and control measures.

Epidemiology and Disease Burden of Respiratory Syncytial Virus Infection in Adults

Respiratory syncytial virus (RSV) constitutes a significant cause of respiratory illness and mortality among older adults, a demographic that is expanding with considerable impact on healthcare systems worldwide. The actual burden of RSV in this population may still be underestimated, owing to factors such as low awareness and suboptimal diagnostic sensitivity in adults, the lack of robust RSV surveillance systems, and the infrequent use of diagnostic testing. Recent advancements in respiratory virus detection have spurred further exploration into appropriate preventive and therapeutic strategies. The recent approval of two vaccines highlights the critical need for the precise estimation of the RSV disease burden to optimize the effectiveness and cost-efficiency of immunization programs. This narrative review aimed to summarize the existing knowledge of the RSV burden in adults with a particular focus on older adults, incorporating data from Korea. Overall, current estimates indicate that the annual RSV attack rate in the general adult population ranges from 1 - 7%, increasing to approximately 4 - 10% among elderly and high-risk groups. The in-hospital mortality rate can be estimated to be around 7 - 10%, rising up to 40% among intensive care unit-admitted patients. To elucidate RSV's disease burden, further continuing research, including population-based studies, is necessary.

Respiratory syncytial virus incidence and typing in the last six seasons in the north of Spain (Asturias). Genetic characterization during the SARS-CoV-2 pandemic

Respiratory syncytial virus is associated with lower respiratory tract infections. As several types and genotypes can circulate at the same time, genomic characterization is important for timely epidemiological control and treatment measures. In the last 6 seasons (2017-2023), 191 236 nasopharyngeal swabs were processed for respiratory viruses to determine the etiology of acute respiratory infections, describe the incidence and distribution of RSV types and enrich the data of epidemiological molecular studies on RSV in Spain. The incidence of RSV reached 7% in the pre-pandemic season. RSV was most frequent in children under 5 years of age (12.6%), but was also significant in those over 70 years of age (5.63%). The measures taken to control SARS-CoV-2 infection were useful for RSV control and the incidence decreased to 1.8%, but caused a change in the types. Pre-pandemic, the majority circulating types were RSV-B/RSV-B/RSV-A and in the pandemic it was RSV-B/RSV-B. In the last season, RSV-B and RSV-A were detected in the same proportion. Genetic characterization showed three new clades. This has been taken into account to understand the epidemiology as well as the development of therapeutic and preventive strategies.

Respiratory syncytial virus infection in adults: Differences with influenza

INTRODUCTION

Respiratory syncytial virus (RSV) causes an acute respiratory illness similar to influenza, although there are few data comparing both of them in adults. The existence of clinical differences between these two infections could have implications for their management.

MATERIALS AND METHODS

Retrospective observational cohort study including 63 adults with positive PCR for RSV and 221 for influenza during winter 2018-2019. Epidemiological, clinical characteristics and outcomes were contrasted between both groups.

RESULTS

Compared to influenza, RSV-positive patients presented a higher association with active neoplasia (OR=2.9; 95% CI: 1.2-6.9), dependence for basic activities of daily living (OR=3.4; 95% CI: 1.4-8.2) and immunosuppression due to chronic glucocorticoid administration (OR=7.6; 95% CI: 1.6-36.1). At diagnosis, fever was less common (OR=0.3; 95% CI: 0.2-0.7), and C-reactive protein level ≥100mg/l was more frequent (OR=2.1; 95% CI: 1.0-4.5). They developed bacterial co-infection by Staphylococcus aureus in a higher proportion (OR=8.3; 95% CI: 1.5-46.9) and presented a greater need for admission to the intensive care unit (OR=5.4; 95% CI: 1.4-19.2).

CONCLUSION

RSV is an important cause of respiratory illness in adults during the influenza season. It especially affects vulnerable patients with chronic underlying diseases, and has a higher morbidity than influenza. For all these reasons, specific detection, prevention and treatment of RSV is necessary in order to reduce the consumption of health care resources due to RSV disease in adults.

Clinical features and outcomes of influenza and RSV coinfections: a report from Canadian immunization research network serious outcomes surveillance network

BACKGROUND

Influenza and RSV coinfections are not commonly seen but are concerning as they can lead to serious illness and adverse clinical outcomes among vulnerable populations. Here we describe the clinical features and outcomes of influenza and RSV coinfections in hospitalized adults.

METHODS

A cohort study was performed with pooled active surveillance in hospitalized adults ≥ 50 years from the Serious Outcomes Surveillance Network of the Canadian Immunization Research Network (CIRN SOS) during the 2012/13, 2013/14, and 2014/15 influenza seasons. Descriptive statistics summarized the characteristics of influenza/RSV coinfections. Kaplan-Meier estimated the probability of survival over the first 30 days of hospitalization.

RESULTS

Over three influenza seasons, we identified 33 cases of RSV and influenza coinfection, accounting for 2.39 cases per 1,000 hospitalizations of patients with acute respiratory illnesses. Adults aged 50 + years commonly reported cough (81.8%), shortness of breath (66.7%), sputum production (45.5%), weakness (33.3%), fever (27.3%), and nasal congestion (24.2%) as constitutional and lower respiratory tract infection symptoms. The mortality rate was substantial (12.1%), and age, comorbidity burden, and frailty were associated with a higher risk for adverse clinical outcomes.

CONCLUSIONS

Older adults are at higher risk for complications from influenza and RSV coinfections, especially those over 65 with a high comorbidity burden and frailty.

All Eyes on the Prefusion-Stabilized F Construct, but Are We Missing the Potential of Alternative Targets for Respiratory Syncytial Virus Vaccine Design?

Respiratory Syncytial Virus (RSV) poses a significant global health concern as a major cause of lower respiratory tract infections (LRTIs). Over the last few years, substantial efforts have been directed towards developing vaccines and therapeutics to combat RSV, leading to a diverse landscape of vaccine candidates. Notably, two vaccines targeting the elderly and the first maternal vaccine have recently been approved. The majority of the vaccines and vaccine candidates rely solely on a prefusion-stabilized conformation known for its highly neutralizing epitopes. Although, so far, this antigen design appears to be successful for the elderly, our current understanding remains incomplete, requiring further improvement and refinement in this field. Pediatric vaccines still have a long journey ahead, and we must ensure that vaccines currently entering the market do not lose efficacy due to the emergence of mutations in RSV's circulating strains. This review will provide an overview of the current status of vaccine designs and what to focus on in the future. Further research into antigen design is essential, including the exploration of the potential of alternative RSV proteins to address these challenges and pave the way for the development of novel and effective vaccines, especially in the pediatric population.

Current state and challenges in respiratory syncytial virus drug discovery and development

Human respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections (LRTI) in young children and elderly people worldwide. Recent significant progress in our understanding of the structure and function of RSV proteins has led to the discovery of several clinical candidates targeting RSV fusion and replication. These include both the development of novel small molecule interventions and the isolation of potent monoclonal antibodies. In this review, we summarize the state-of-the-art of RSV drug discovery, with a focus on the characteristics of the candidates that reached the clinical stage of development. We also discuss the lessons learned from failed and discontinued clinical developments and highlight the challenges that remain for development of RSV therapies.

Economic burden of respiratory syncytial virus in adults in Germany - a health claims analysis between 2015 and 2018

AIMS

Respiratory syncytial virus (RSV) causes severe lower respiratory tract infections (LRTI) in infants and adults. While the clinical burden was recently estimated in adults in Germany, little is known about the economic burden. To fill this gap, this study aimed to assess hospital and outpatient healthcare resource utilization (HRU) and costs of RSV infections in adults in Germany.

METHODS

In this retrospective, observational study on nationwide, representative, anonymized claims data (2015-2018), we identified patients ≥18 years with ICD-10-GM-codes specific to RSV ("RSV-specific"). To increase sensitivity, patients with unspecified LRTIs (including unspecified bronchitis, bronchiolitis, bronchopneumonia, and pneumonia) during RSV seasons were also included as cases potentially caused by RSV ("RSV-possible"). RSV-related HRU (hospital days, ICU and ventilation treatment, drug dispensation) and direct costs were estimated per episode. Excess costs per episode and for follow-up periods were compared to a matched control cohort. All outcomes were reported per healthcare sector and stratified by age and risk groups as well as disease severity (ICU admission/ventilation).

RESULTS

Direct inpatient and outpatient mean episode costs were 3,473€ and 82€, respectively, with substantially higher costs for severe cases requiring intensive care and/or ventilation (10,801€). Direct costs for RSV-specific cases were higher than for RSV-possible cases (inpatients: 6,247€ vs. 3,450€; outpatients: 127€ vs. 82€). Moreover, costs were significantly higher for RSV patients than for controls and increased over time (inpatients: 5,140€ per episode vs 10,093€ per year; outpatients: 46€ per quarter vs 114€ per year).

LIMITATIONS

While the number of RSV-specific cases was low, inclusion of seasonal LRTI cases likely increased the sensitivity to detect RSV cases and allowed a better estimation of the total costs of RSV.

CONCLUSIONS

The economic burden of RSV-LRTI in adults in Germany is substantial, persists long-term, and is particularly high in the elderly. This highlights the need for cost-effective prevention measures.

RSV vaccination in older adults: Addressing vaccine hesitancy using the 3C model

The first vaccine against respiratory syncytial virus (RSV) targeting older adults was approved for use in Canada in August 2023. As a frequent first point of contact for Canadians seeking advice on vaccination and the most common setting for the administration of influenza vaccines, community pharmacies will also play a role in RSV vaccination efforts. To address vaccine hesitancy confidently and effectively, pharmacists must be equipped with knowledge of the factors that affect a person's decision on whether to be vaccinated or not. The 3C Model of Vaccine Hesitancy summarizes these as complacency, confidence and convenience. This article introduces the model and describes the often-underrecognized relevance of RSV to older adults, including risk factors and burden of disease. It also reviews the history and status of vaccine development and approval and presents clinical trial data to equip pharmacists to discuss RSV vaccination with older adults who express vaccine hesitancy.

Comparative analysis of mortality in patients admitted with an infection with influenza A/B virus, respiratory syncytial virus, rhinovirus, metapneumovirus or SARS-CoV-2

Background

While influenza virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are recognised as a cause of severe illness and mortality, clinical interest for respiratory syncytial virus (RSV), rhinovirus and human metapneumovirus (hMPV) infections is still limited.

Methods

We conducted a retrospective database study comparing baseline characteristics and 30-day mortality in a large cohort of adult patients admitted for an overnight stay or longer with an influenza virus (A/B), rhinovirus, hMPV, RSV or SARS-CoV-2 infection. For non-SARS-CoV-2 viruses, data were included for the period July 2017-February 2020. For SARS-CoV-2, data between March 2020 and March 2022 were included.

Results

Covariate-adjusted 30-day mortality following RSV, hMPV or rhinovirus infections was substantial (crude mortality 8-10%) and comparable with mortality following hospitalisation with an influenza A virus infection. Mortality following a SARS-CoV-2 infection was consistently higher than for any other respiratory virus, at any point in time (crude mortality 14-25%). Odds of mortality for SARS-CoV-2 compared with influenza A declined from 4.9 to 1.7 over the course of the pandemic. Patients with SARS-CoV-2 infection had less comorbidity than patients with other respiratory virus infections and were more often male. In this cohort, age was related to mortality following hospitalisation, while an association with comorbidity was not apparent.

Conclusions

With the exception of SARS-CoV-2 infections, we find the clinical outcome of common respiratory virus infections requiring hospitalisation more similar than often assumed. The observed mortality from SARS-CoV-2 was significantly higher, but the difference with other respiratory viruses became less distinct over time.

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

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.

Respiratory syncytial virus among hospitalized patients of severe acute respiratory infection in Bhutan: Cross-sectional study

Introduction

Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections worldwide, particularly in young children. In Bhutan, respiratory disease continues to be among the top 10 diseases of morbidity for several years. This study aimed to estimate the prevalence of RSV among hospitalized patients with severe acute respiratory infection (SARI) in Bhutan.

Method

Respiratory specimens were collected from SARI patients of all ages in 2016 and 2018 following influenza surveillance guidelines. Specimens were tested for influenza and RSV, human metapneumovirus, adenovirus, and human parainfluenza virus types 1, 2, and 3 using real-time reverse-transcription polymerase chain reaction assay. Descriptive statistics were used to analyze the result in STATA 16.1.

Result

Of the 1339 SARI specimens tested, 34.8% were positive for at least one viral pathogen. RSV was detected in 18.5% of SARI cases, followed by influenza in 13.4% and other respiratory viruses in 3%. The median age of SARI cases was 3 (IQR: 0.8-21 years) years. RSV detection was higher among children aged 0-6 (Adj OR: 3.03; 95% CI: 1.7-5.39) and 7-23 months (Adj OR: 3.01; 95% CI: 1.77-5.12) compared with the children aged 5-15 years. RSV was also associated with breathing difficulty (Adj OR: 1.73; 95% CI: 1.17-2.56) and pre-existing lung disease, including asthma (Adj OR: 2.78; 95% CI: 0.99-7.8).

Conclusion

Respiratory viruses were detected in a substantial proportion of SARI hospitalizations in Bhutan.

Characteristics and outcomes of patients hospitalized for infection with influenza, SARS-CoV-2 or respiratory syncytial virus in the season 2022/2023 in a large German primary care centre

BACKGROUND

In 2022/2023, Influenza A and Respiratory Syncytial Virus (RSV) reappeared in hospitalized patients, which was in parallel to ongoing SARS-CoV-2 infections. The aim of our study was to compare the characteristics and outcomes of these infections during the same time.

METHODS

We included patients of all ages with a positive polymerase chain reaction (PCR) test for Influenza A/B, RSV, or SARS-CoV-2 virus hospitalized in the neurological, internal or paediatric units of the RoMed Hospital Rosenheim, Germany, between October 1st 2022 and February 28th 2023.

RESULTS

A total of 906 patients were included (45.6% female; median age 68.0 years; 21.9% Influenza A, 48.2% SARS-CoV-2, 28.3% RSV). Influenza B (0.2%) and co-infections (1.5%) played a minor role. In patients aged ≥ 18 years (n = 637, 71%), Influenza A, SARS-CoV-2 and RSV groups differed in age (median 72, 79, 76 years, respectively; p < 0.001). Comorbidities, particularly asthma and COPD, were most prevalent for RSV. 103 patients were admitted to the intensive care unit (ICU) (16.3% Influenza A, 15.3% SARS-CoV-2, 19.2% RSV; p = 0.649), 56 died (6.8% Influenza A, 9% SARS-CoV-2, 11.1% RSV; p = 0.496). RSV showed the highest frequencies of low-flow oxygen supplementation for admission and stay. Differences in the length of stay were minor (median 7 days). Conversely, in patients aged < 18 years (n = 261, 28,8%), 19.5%, 17.6% and 60.2% were in the Influenza A, SARS-CoV-2 and RSV groups, respectively; 0.4% showed Influenza B and 2.3% co-infections. 17 patients were admitted to ICU (3.9% Influenza A, 9.6% RSV, 0% SARS-CoV-2); none died. RSV showed the highest frequencies of high- and low-flow oxygen supplementation, SARS-CoV-2 the lowest.

CONCLUSION

When comparing infections with Influenza, SARS-CoV-2 and RSV in the winter 2022/2023 in hospitalized adult patients, rates of ICU admission and mortality were similar. RSV showed the highest frequencies of obstructive airway diseases, and of oxygen supplementation. The latter was also true in children/adolescents, in whom RSV dominated. Thus, in the situation of declining importance of SARS-CoV-2, RSV showed a disease burden that was relatively higher than that from Influenza and SARS-CoV-2 across ages, and this might be relevant for the seasons coming.

Respiratory syncytial virus in adults with comorbidities: an update on epidemiology, vaccines, and treatments

BACKGROUND

Respiratory syncytial virus (RSV) is widely known as a frequent cause of respiratory distress among adults, particularly in older people. Recent years have witnessed several improvements in respiratory virus detection, leading to more questions about therapeutic management strategies.

OBJECTIVES

This narrative review focuses on the RSV burden in older people and adults with risk factors and provides an update on the main recent developments regarding managing this infection.

SOURCES

A comprehensive PubMed search was conducted till August 2023 to identify studies on RSV among the adult population. We included observational studies, RCTs on vaccines, and different therapies.

CONTENT

This review should give clinicians an overview of RSV epidemiology and burden among older people and adults with pre-existing risk factors, the most recent randomized clinical trials on RSV vaccines, and the existing data on the different therapeutics existing and under development.

IMPLICATIONS

There is a growing body of evidence on RSV burden in adults. The landscape of preventive and curative treatments is quickly evolving.

Respiratory syncytial virus burden and risk factors for severe disease in patients presenting to the emergency department with flu-like symptoms or acute respiratory failure

BACKGROUND

Predictors of Respiratory Syncytial Virus (RSV) infection and determinants of RSV unfavorable outcomes are still unclear. We assessed RSV burden and investigated the risk factors associated with RSV positive swab and RSV severe disease.

METHODS

A retrospective, single center, cohort study included all consecutive patients referred to the emergency department of L. Sacco University Hospital (Milan) with flu-like symptoms or acute respiratory failure (aRF) tested per protocol for SARS-CoV-2, RSV, Influenza A (InvA) during the 2022-2023 autumn/winter season. Clinical characteristics and patients' outcomes were registered. Respiratory failure, need for respiratory support, shock, sepsis or in-hospital death defined severe disease.

MAIN FINDINGS

The analysis included 717 patients (65.1% negative swab, 14.1% InvA, 8.5% RSV, 8.6% SARS-CoV-2, 3.6% other viruses). Compared with the study cohort, RSV patients had the highest occurrence of aRF (62.7%) and severe disease (70.5%); mortality was similar to InvA (6.6% vs 5.9%, p = 0.874). Compared with InvA patients, RSV patients were older (p = 0.009), had higher Charlson index (p = 0.001), higher prevalence of chronic heart failure (p = 0.001) and were more frequently on ICS (p = 0.026) and immunosuppressants (p = 0.018). Heart failure [OR (95%CI):3.286 (1.031-10.835); p = 0.041], chronic exposure to ICS [OR (95%CI):2.377 (1.254-4.505); p = 0.008] and immunosuppressants [OR (95%CI):3.661 (1.246-10.754); p = 0.018] predicted RSV infection. Glycaemia ≥120 mg/dL [OR (95%CI):5.839 (1.155-29.519); p = 0.033], leucocytes ≥8000 cells/μL [OR (95%CI):5.929 (1.090-32.268); p = 0.039], and past/active smoking [OR (95%CI):7.347 (1.301-41.500); p = 0.024] predicted severe RSV disease.

CONCLUSIONS

RSV infection is associated with significant mortality and morbidity. Preventive strategies for RSV infection such as vaccination are highly warranted, especially in older patients with cardiovascular and chronic respiratory conditions.

Reply to Standaert, B. Comment on "Postma et al. Predicted Public Health and Economic Impact of Respiratory Syncytial Virus Vaccination with Variable Duration of Protection for Adults ≥60 Years in Belgium"

We have read the commentary from Baudouin Standaert [...].

Comment on Postma et al. Predicted Public Health and Economic Impact of Respiratory Syncytial Virus Vaccination with Variable Duration of Protection for Adults ≥60 Years in Belgium. Vaccines 2023, 11, 990

Presently, there are at least five important vaccine producers that have already launched or intend to launch a new vaccine designed to prevent infections caused by the Respiratory Syncytial Virus (RSV), which is highly prevalent in the youngest as well as the oldest age groups [...].