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

Respiratory syncytial virus vaccination in older adults and patients with chronic disorders: A position paper from the Portuguese Society of Pulmonology, the Portuguese Association of General and Family Medicine, the Portuguese Society of Cardiology, the Portuguese Society of Infectious Diseases and Clinical Microbiology, the Portuguese Society of Endocrinology, Diabetes and Metabolism, and the Portuguese Society of Internal Medicine

BACKGROUND

Respiratory syncytial virus (RSV) is an important cause of lower respiratory tract infection, hospitalisation and death in adults.

METHODS

Based on evidence regarding the impact of RSV on adult populations at risk for severe infection and the efficacy and safety of RSV vaccines, the Portuguese Society of Pulmonology, the Portuguese Association of General and Family Medicine, the Portuguese Society of Cardiology, the Portuguese Society of Infectious Diseases and Clinical Microbiology, the Portuguese Society of Endocrinology, Diabetes and Metabolism, and the Portuguese Society of Internal Medicine endorses this position paper with recommendations to prevent RSV-associated disease and its complications in adults through vaccination.

CONCLUSION

The RSV vaccine is recommended for people aged ≥50 years with risk factors (chronic obstructive pulmonary disease, asthma, heart failure, coronary artery disease, diabetes, chronic kidney disease, chronic liver disease, immunocompromise, frailty, dementia, and residence in a nursing home) and all persons aged ≥60 years. If it cannot be made available to this population, then the vaccine should be prioritised for individuals aged ≥75 years and those aged ≥50 years with risk factors. The vaccine should preferably be given between September and November and can be co-administered with the influenza vaccine. Ongoing studies on RSV vaccines may justify extending these recommendations in the future.

Respiratory syncytial virus pulmonary infections in adults - disease burden and prevention

PURPOSE OF REVIEW

We highlight the evolving understanding of the burden of respiratory syncytial virus (RSV) in older adults and recent data on the three new vaccines.

RECENT FINDINGS

As well as a greater recognition of the amount of RSV infection in adults, and especially over 60 years of age, there has been a significant amount of study detailing the postacute burden including excess cardiovascular disease and loss of physical and cognitive functioning. Three new RSV vaccines now have published data for two seasons, and while direct comparison is not possible due to differences in the timing, methodology and populations studies, all show good efficacy with no serious side effects of concern.

SUMMARY

RSV causes a substantial amount of morbidity and mortality in older adults with both acute and longer term impacts. With effective vaccines now available clinicians should be advocating with their patients to prevent RSV infection.

Host immune response to respiratory syncytial virus infection and its contribution to protection and susceptibility in adults: a systematic literature review

INTRODUCTION

Respiratory syncytial virus (RSV) is an important pathogen in infants, children, older adults, and those with comorbidities. Mechanisms involving viral proteins appear to underly the ability of RSV to evade and modulate host immunity. We aimed to understand virus- and host-dependent factors regulating the development and severity of RSV infection, as relate to the prevention and treatment of RSV-associated disease in adults, through a systematic literature review (SLR).

METHODS

An SLR was conducted to identify immune mechanisms involved in the protective response to RSV infection in adults, and responses that may contribute to the development of severe disease. Concurrent searches (MEDLINE/Embase) using embase.com identified relevant papers published between 1990 and 19 April 2023.

RESULTS

Of 1813 records identified, 113 were selected for review. Inclusion criteria were based on relevant patient populations, outcomes, and study methodologies. RSV is common, recurrent, and associated with high morbidity and mortality in older adults and people with underlying chronic diseases. Immune responses differ between younger and older adults. The approval of effective vaccines may protect older individuals from symptomatic RSV infection.

CONCLUSIONS

We established the complexities of RSV immune response, but further research is required to fully understand anti-RSV immunology.

Respiratory syncytial virus vaccine uptake among adults aged ≥60 years in a large, integrated healthcare system in Southern California 2023-2024

During the 2023-2024 respiratory syncytial virus (RSV) season, vaccination was recommended for adults ≥60 years based on shared clinical decision-making with their healthcare providers. We examined RSV vaccine uptake and characteristics associated with uptake among age-eligible Kaiser Permanente Southern California (KPSC) patients. Our study cohort included all patients ≥60 years from September 23, 2023 (i.e., date RSV vaccination first became available at KPSC; N = 1,003,132) to April 9, 2024 (i.e., end of local RSV season). To identify sociodemographic and clinical characteristics associated with RSV vaccination, we used multivariable robust Poisson regression to estimate the adjusted relative risk (aRR) and 95 % CI. Overall, 7.6 % of patients were vaccinated for RSV. In multivariable regression analyses, those aged 70-79.9 years (aRR: 1.36; 95 % CI: 1.34-1.39) and aged ≥80 years (aRR: 1.35; 95 % CI: 1.32-1.38) were more likely to be vaccinated, compared with those aged 60-69.9 years. Compared with Non-Hispanic White patients, Asian (aRR: 0.95; 95 % CI: 0.93-0.97), Hispanic (aRR: 0.52; 95 % CI: 0.51-0.54), Non-Hispanic Black (aRR: 0.69; 95 % CI: 0.67-0.71), Pacific Islander (aRR: 0.91; 95 % CI: 0.84-0.98), and Native American or Alaska Native (aRR: 0.80; 95 % CI: 0.70-0.92) patients were less likely to be vaccinated. Those in higher neighborhood deprivation quartiles were less likely to be vaccinated (Q2: aRR: 0.86; 95 % CI: 0.85-0.88; Q3: aRR: 0.77; 95 % CI: 0.76-0.79; and Q4: aRR: 0.67; 95 % CI: 0.65-0.68), compared with those in the lowest deprivation quartile. We found low vaccination uptake and identified disparities in vaccination that might exacerbate existing disparities in RSV infection and severe RSV disease among certain populations. CDC's ACIP recently updated their recommendations for all adults 75+ years, and this might begin to address these disparities.

Severity and outcomes of adult respiratory syncytial virus inpatient compared with influenza: observational study from Japan

BACKGROUND

Respiratory syncytial virus (RSV) significantly impacts not only children but also adults. However, knowledge of the severity and outcomes among adult RSV inpatients is still limited.

OBJECTIVES

To clarify the short- and long-term health threats associated with adult RSV infections.

METHODS

This retrospective observational study included 56,980 adult inpatients aged 18 years and older due to RSV or influenza infection between April 2010 and March 2022. After inverse probability weighting adjustment, we used Poisson's regression to estimate the risk of outcomes.

RESULTS

The RSV group had a higher risk of requiring mechanical ventilation during hospitalization compared to the influenza group (9.7% vs. 7.0%; risk ratio (RR), 1.35; 95% confidence interval (CI), 1.08-1.67). In-hospital mortality was comparable between RSV and influenza groups (7.5% vs. 6.6%; RR, 1.05; 95% CI, 0.82-1.34). RSV group was associated with increased risk of readmission within 1 year after surviving discharge (34.0% vs. 28.9%; RR, 1.19; 95% CI, 1.07-1.32) and all-cause mortality within 1 year of admission (12.9% vs. 10.3%; RR, 1.17; 95% CI, 1.02-1.36). In the age-stratified analysis, the RSV group aged 60 years and older had a higher risk than the influenza group for in-hospital death, readmission and all-cause mortality within one year.

CONCLUSIONS

RSV infections demonstrated comparable or greater health threats than influenza infections not only during hospitalization but also in long-term outcomes. The findings underscore the threat of RSV in adults, the impact on healthcare systems and the need for continued development of public health counter measures against RSV.

Clinical features of respiratory syncytial virus and influenza infections in hospitalized adults across three Italian regions

Acute respiratory infections (ARIs) are important causes of morbidity and mortality globally. Respiratory syncytial virus (RSV) is a highly transmissible viral pathogen that is associated with ARIs, with both RSV and influenza virus infections being leading causes of hospitalization in older (especially frail) individuals. However, prospectively collected data on the incidence of RSV infection are scarce. This prospective study sought to estimate the prevalence of and characterize RSV and influenza virus infection in hospitalized patients. Adult patients (≥18 years of age) who were admitted to the respiratory ward of three major hospitals in northern Italy were included in the study and, therefore, had a nasal swab and underwent routine clinical, laboratory, and imaging testing. The primary objective was to estimate the prevalence of influenza virus and RSV infection in these patients. A total of 246 patients were recruited, 36 of whom had a viral or bacterial respiratory infection. Of these, 9 (3.7% of the total included patients or 25.0% of those with any infection) tested positive for the influenza virus, 5 (55.6%) of whom developed acute respiratory failure, with one dying by 3 months post-discharge. A further 3 patients (1.2% of the total included patients or 8.3% of those with any infection) tested positive for RSV. The three patients with RSV had a greater level of dyspnea and greater severity than those with any infection, and all had pneumonia and developed acute respiratory failure, with one dying during hospitalization. Influenza and RSV infections were identified in patients hospitalized in respiratory wards in Northern Italy. The severe nature of the disease in these patients, including a high rate of pneumonia, emphasizes the importance of preventative measures to protect this vulnerable population and, in particular, vaccination.

Disparities in Respiratory Syncytial Virus Risk Factors, Diagnosis, and Outcomes in Adults by Race, Ethnicity, and Other Social Determinants of Health in the United States

INTRODUCTION

Respiratory syncytial virus (RSV) vaccination could improve health equity by protecting individuals who are disproportionally at increased risk of RSV infection and severe RSV-related outcomes. However, limited information is available about RSV-related disparities among United States (US) adults.

AREAS COVERED

We reviewed US-specific literature regarding disparities across adult populations in having risk factors for severe RSV disease (cardiopulmonary disease, diabetes, liver disease, kidney disease). We summarize available evidence regarding disparities in having or being diagnosed with RSV, as well as experiencing severe RSV-related health outcomes. Disparities are analyzed by race, ethnicity, socioeconomic status, and other social determinants of health.

EXPERT OPINION

RSV-related disparities are observed across all outcomes of interest, although RSV-specific data are limited in some cases. Racial and ethnic minority groups and socioeconomically disadvantaged populations are more likely to have risk factors for severe RSV disease, overall and at younger ages, yet individuals from these groups are more often underdiagnosed. Disparities in RSV-related hospitalizations, emergency department visits, and deaths are observed, especially among adults from racial and ethnic minority groups, of lower socioeconomic status, and in poorer or more crowded neighborhoods. Findings highlight the importance of RSV vaccination among these groups to improve health equity.

Healthcare Professionals' Knowledge, Attitudes, and Practices Regarding Respiratory Syncytial Virus Disease and Vaccination in Adults Aged 60 Years and Older

INTRODUCTION

The burden of respiratory syncytial virus (RSV) disease is substantial among adults aged ≥ 60 years and adults with risk factors for severe RSV. This study assessed the knowledge, attitudes, and practices of healthcare professionals (HCPs) related to RSV disease and vaccination, with a focus on adults aged ≥ 60 years.

METHODS

During November 14-30, 2023, a cross-sectional, web-based survey was administered to HCPs, targeting a total of 600 primary care physicians (PCPs), specialist physicians, nurse practitioners (NPs)/physician assistants (PAs), and pharmacists. Survey questions evaluated knowledge about RSV disease, vaccines, and vaccination recommendations; RSV-related attitudes and perceptions; and RSV vaccination practices. Responses were analyzed descriptively, overall and by HCP subgroup. Multivariable logistic regression models were used to explore HCP characteristics associated with RSV vaccination knowledge and practices.

RESULTS

Of the 603 respondents (148 PCPs, 151 specialist physicians, 150 NPs/PAs, and 154 pharmacists), 63.0% were very familiar with RSV disease in patients aged ≥ 60 years. Although most HCPs recognized the benefits of RSV vaccination within this patient population, many HCPs were not fully knowledgeable about RSV vaccine recommendations, and 33.5% had not recommended, prescribed, or administered any RSV vaccine to patients aged ≥ 60 years in the previous 3 months. In multivariable regression analyses, HCP familiarity with RSV disease (among other factors) was consistently associated with RSV vaccination knowledge and practices.

CONCLUSIONS

This study characterized RSV disease- and vaccine-related knowledge, attitudes, and practices among HCPs in the United States during the first season of RSV vaccine availability for adults aged ≥ 60 years. These findings can help to inform HCP and patient education efforts to address potential RSV vaccination knowledge gaps and ensure equitable access to RSV vaccines among older adults.

Comparison of patients presenting to emergency departments infected with respiratory syncytial virus versus influenza virus: A retrospective cohort study

OBJECTIVE

In recent years, there has been increased awareness of the impact of respiratory syncytial virus (RSV) on adult health, especially in elderly patients. Unlike influenza infection, its presentation and patient outcomes are not well studied. The aim of this study was to compare clinical outcomes in emergency department patients infected by RSV vs influenza.

METHODS

This was a multicenter retrospective study in seven emergency departments (ED) in France. Patients with a laboratory-confirmed RSV or influenza infection in the ED were included between January 2017 and December 2022. The primary endpoint was in-hospital mortality truncated at day 28. Secondary endpoints included one year occurrence of thrombo-embolic event, acute coronary syndrome, and stroke.

RESULTS

3397 patient charts were screened, and 3224 were analyzed. Of these, 551 (17 %) patients had RSV-positive PCR, and 2673 (83 %) had influenza-positive PCR. Patients with RSV were older (median age 73 vs. 68; difference, -5.00 % points [CI, -4.0 to -6.0 % points])), and had more comorbidities (15.0 % vs 22.0 % difference, -6.92 % points [CI, -10.6 to -3.21 % points])), compared to those with influenza. There was no significant difference in in-hospital mortality rate at day 28: 3.82 % for influenza vs. 4.72 % for RSV (adjusted OR 0.93, 95 %CI [0.59-1.46] p = 0.73). There was no significant difference in the occurrence of the secondary endpoints.

CONCLUSIONS

In this large study of ED patients, although RSV patients were more fragile, no significant differences were found in in-hospital mortality or the occurrence of cardiovascular or thromboembolic events between RSV and influenza infections.

Short-term and Long-term Mortality Following Hospitalized and Ambulatory Lower Respiratory Tract Illnesses Among US Adults

Background

Lower respiratory tract illness (LRTI) is a significant cause of morbidity among adults, particularly older adults and adults with underlying medical conditions. Evidence on short- and long-term risks of mortality among adults requiring hospitalization or ambulatory care for LRTI, overall and within subgroups, is currently lacking.

Methods

A retrospective observational matched-cohort design and Optum's de-identified Clinformatics Data Mart Database (2012-2019) were used. The study population included adults who were hospitalized or received ambulatory care for LRTI and matched (1:1) comparison patients. All-cause mortality was ascertained during the 30-, 60-, 90-, 180-, and 360-day periods following the beginning of the LRTI episode. Risks of mortality were estimated for all LRTI patients and comparison patients as well as within age/comorbidity-specific subgroups.

Results

Among LRTI-hospitalized patients (n = 60.2K), 30-day mortality risk was 5.8% and 360-day risk was 18.3%, 7.5 and 2.6 times higher than corresponding values for comparison patients. Among LRTI-ambulatory patients (n = 2.4M), 30-day mortality risk was 1.2% and 360-day risk was 3.6%, 6.5 and 2.1 times higher than comparison patients. Among both LRTI-hospitalized and LRTI-ambulatory patients, mortality risk increased with increasing age and was higher for adults with chronic or immunocompromising conditions (vs without medical conditions).

Conclusions

Short- and long-term mortality were higher among patients who were hospitalized or received ambulatory care for LRTI vs matched comparison patients, and risks increased markedly with increasing age and worsening comorbidity profile. Strategies for preventing LRTI, especially among persons at elevated risk, may reduce premature deaths and yield important public health benefits.

Knowledge, attitude, and perception regarding the respiratory syncytial virus vaccine among healthcare professionals

Background

Respiratory syncytial virus (RSV) is a significant respiratory pathogen. Despite vaccine availability, uptake remains low, and healthcare professionals play a key role in promoting immunisation. This study aims to evaluate healthcare providers' knowledge, perceptions and practices regarding the RSV vaccine.

Methods

A validated survey was distributed to healthcare professionals. The study questionnaire contained sections to assess sociodemographic characteristics, knowledge of RSV and its vaccines, healthcare professionals' perception towards RSV and its vaccines, and their perception towards the potential barriers against RSV vaccination. The last section assesses physicians' previous practice in dealing with RSV infection.

Results

Over half of the participants (56.6%) had no prior awareness of RSV, though many recognised its potential severity, particularly in vulnerable populations like children and older adults (52.6%). Awareness of FDA-approved RSV vaccines was limited, with only 28.1% of respondents familiar with vaccines intended for older adults. Views on vaccination recommendations for older age groups were divided; 23.7% supported vaccination for those 75 and older, while 31.1% advocated for vaccination in those aged 60-74 at higher risk. Perceived barriers to RSV vaccination were prominent. Most respondents (85.1%) cited concerns about vaccine safety as a key obstacle, and 81.1% identified out-of-pocket costs as a significant barrier. Testing for RSV was infrequent (24.6%), mainly due to a lack of effective treatment. Most participants (96.9%) called for greater awareness and education about RSV vaccines, and 91.2% supported recommending the vaccine if it was available and free.

Conclusion

This study reveals significant gaps in healthcare professionals' knowledge and practices regarding RSV and its vaccines, with substantial barriers to vaccine adoption. Targeted education, improved diagnostics, and addressing vaccine barriers are essential strategies for improving the healthcare response to RSV.

Costs and Complications of Respiratory Syncytial Virus and Acute Respiratory Infections in the Adult Population: Analysis of a German Claims Database

BACKGROUND

Respiratory syncytial virus (RSV) infections pose health and economic burdens to adults. Using claims data, we estimated RSV-associated costs, healthcare resource utilization (HCRU), and complication rates from patients of a nationwide German health insurance database.

METHODS

We analyzed confirmed RSV, RSV-possible, and acute respiratory infection (ARI) cohorts, plus 1:1 matched control cohorts of individuals ≥ 18 years from 2010 to 2019. Matching was performed separately for patients 18-49, 50-59, and ≥ 60 years. Medical costs, HCRU, and sick leave were assessed for inpatients and outpatients. Complications were compared between cases and controls, and logistic regression assessed odds ratios (ORs) for risk.

RESULTS

Altogether, 2668 confirmed RSV index episodes occurred. In ≥ 60-year-olds, 862 episodes incurred mean excess costs of €3773 (95% confidence interval [CI]: €2956-€4591) per episode during the index quarter and €3286 (95% CI: €1841-€4732) in the following four quarters. Mean costs were €5553 per episode for inpatients and €116 for outpatients. In ≥ 60-year-olds, risk for congestive heart failure hospitalization (OR 2.3; 95% CI: 1.4-3.8), exacerbation of asthma (OR 6.0; 95% CI: 1.7-20.9), and chronic obstructive pulmonary disease (OR 3.9; 95% CI: 2.6-5.8) were higher for confirmed RSV than controls. In younger groups, costs, HCRU, and complications were also higher in cases than controls. The complication frequencies increased with age. RSV-possible episodes incurred mean excess costs of €615 (95% CI: €605-€626) during the index quarter and €610 (95% CI: €583-€637) during the following four quarters, while in the ARI cohort, the excess costs were €1003 (95% CI: €991-€1015) during the index quarter and €1003 (95% CI: €973-€1032) in the following four quarters. For all three cohorts, individuals who had comorbidities, were immunocompromised, or living in long-term care facilities incurred higher costs.

CONCLUSIONS

Confirmed RSV is associated with high excess costs - especially in hospital settings - and HCRU. Complication risk increased with RSV presence.

RSV F evolution escapes some monoclonal antibodies but does not strongly erode neutralization by human polyclonal sera

Vaccines and monoclonal antibodies targeting the respiratory syncytial virus (RSV) fusion protein (F) have recently begun to be widely used to protect infants and high-risk adults. Some other viral proteins evolve to erode polyclonal antibody neutralization and escape individual monoclonal antibodies. However, little is known about how RSV F evolution affects antibodies. Here we develop an experimental system for measuring neutralization titers against RSV F using pseudotyped lentiviral particles. This system is easily adaptable to evaluate neutralization of relevant clinical strains. We apply this system to demonstrate that natural evolution of RSV F leads to escape from some monoclonal antibodies, but at most modestly affects neutralization by polyclonal serum antibodies. Overall, our work sheds light on RSV antigenic evolution and describes a tool to measure the ability of antibodies and sera to neutralize contemporary RSV strains.

Update on vaccines against respiratory syncytial virus (RSV): A narrative review

Respiratory syncytial virus (RSV) infections pose a significant challenge to healthcare systems due to their impact on older adults, particularly those who are frail. Implementing an appropriate vaccination policy for these patients could help reduce healthcare resource utilization and costs while enhancing the quality of life for elderly individuals and their families. This narrative review aims to present the latest evidence on RSV and the available vaccines. Of the five vaccines evaluated, three have demonstrated significant efficacy in individuals over 60 years of age. Based on the current evidence, it is recommended that individuals over 75 be offered RSV vaccination, with priority given to those with chronic heart or lung conditions, frailty, or who reside in long-term care facilities.

Burden of Respiratory Syncytial Virus Disease in Adults with Asthma and Chronic Obstructive Pulmonary Disease: A Systematic Literature Review

PURPOSE OF REVIEW

Accumulating data indicate that asthma and chronic obstructive pulmonary disease (COPD) increase the risk of severe respiratory syncytial virus (RSV) infection. This systematic literature review assessed the burden of RSV disease among adults ≥ 18 years with asthma or COPD.

RECENT FINDINGS

Data on the prevalence of asthma or COPD among RSV-infected adults, RSV-related hospitalizations, complications, and mortality were collected from studies published between January 1, 2000 and November 28, 2023 in PubMed, Embase, and grey literature. All extracted data were analyzed descriptively. Pooled estimates of asthma or COPD prevalence among RSV-infected adults were calculated from generalized linear mixed effects model meta-analyses. Forty studies were included. The prevalence of asthma and COPD among RSV-infected adults was high, especially in inpatient settings with pooled estimates (95% confidence interval) of 19.3% (15.0-24.6) for asthma and 30.8% (26.1-36.0) for COPD. Adults with asthma or COPD were more likely to be hospitalized following RSV infection than those without these conditions. The incidence rate ratios of hospitalization were 2.0-3.6 (crude) and 6.7-8.2 (adjusted) for asthma and 3.2-13.4 (crude) and 9.6-9.7 (adjusted) for COPD. The most frequently reported RSV-related complications were exacerbation of asthma (up to 64.9%) and COPD (up to ≥ 83.0%). In-hospital case fatality rates were 2.6-4.3% (asthma) and 2.8-17.8% (COPD). These comprehensive data showing a high RSV disease burden in adults with asthma or COPD can be used to inform policy decisions around RSV vaccines and improve preventive care in this high-risk population.

Mexican Interdisciplinary Consensus on the Diagnosis and Preventive Measures for Respiratory Syncytial Virus Infections

BACKGROUND

Respiratory syncytial virus (RSV) is a common cause of respiratory illness in children and adults in Latin America and Mexico. RSV circulates with seasonal peaks in fall and winter. Individuals at highest risk for severe infection are premature infants and those with comorbidities, as well as older adults with cardiopulmonary pathologies and/or varying degrees of immunocompromise.

OBJECTIVE

To provide an updated landscape of the epidemiology, risk groups, diagnostic methods, and prevention of RSV infection in Mexico.

METHODS

Convened by the Asociación Mexicana de Infectología y Microbiología Clínica, 28 interdisciplinary experts participated in a consensus meeting held in November 2023. Four groups, each with seven experts and a medical writer, were formed to discuss epidemiology and diagnosis, risk groups, vaccines, and monoclonal antibodies (mABs). Predefined questions, formulated by a team of four experts, were discussed within each group, and consensus was reached on the answers. These responses were then analyzed and organized into recommendations based on national and international evidence.

RESULTS

Evidence-based recommendations for epidemiological surveillance, diagnosis, and prevention of RSV infection were proposed. Future perspectives regarding the usefulness of new vaccines and passive immunoprophylaxis were analyzed.

CONCLUSIONS

Timely identification of at-risk populations, diagnosis and treatment of RSV infection, and particularly the rational use of mABs and vaccines are key strategies to reduce the clinical and epidemiological burden of RSV infection.

Sewage surveillance revealed the seasonality and prevalence of respiratory syncytial virus and its implications for seasonal immunization strategy in low and middle-income regions of China

Respiratory syncytial virus (RSV) represents a significant global health threat, with a disproportionately high disease burden in low and middle-income regions (LMIRs). Estimating the prevalence of RSV infection at the community levels remains a huge challenge, particularly in LMIRs where clinical data are scarce. In this study, we first detected RSV RNA in the fecal samples from 300 patients to understand the fecal shedding patterns of RSV. Meanwhile, we conducted sewage surveillance of RSV in four geographically distinct LMIRs in China from April 2023 to June 2024. Real-time reverse transcription quantitative Polymerase Chain Reaction (RT-qPCR) was employed to monitor the dynamics of sewage RSV concentration in a typical sewershed from Yingkou, Xi'an, Nanchang, and Nanning, respectively. Subsequent amplicon sequencing was conducted to understand the genotype and mutations of sewage RSV. Through RT-qPCR, we observed two RSV epidemics that lasted from late April to May and October to February in both Yingkou and Xi'an. For Nanchang, only one RSV epidemic was observed which emerged from September to February. Notably, in Nanning, a prolonged RSV epidemic was observed from August to April, suggesting RSV vaccination in Nanning faced more challenges. Amplicon sequencing revealed that sewage RSV found in four LMIRs is genetically distinct, highlighting the need for local initiatives for wastewater monitoring of RSV. This study filled the gaps in previous assessment of suitability of RSV vaccination in LMIRs based on clinical surveillance, demonstrating the effectiveness of wastewater surveillance in guiding public health interventions.

Hospitalization cost estimates of respiratory syncytial virus and influenza infections in adults in Spain, 2016-2019

Respiratory syncytial virus (RSV) is increasingly a recognized cause of severe respiratory infection among adults. This retrospective observational study compared the costs of RSV and influenza hospitalizations in adults aged ≥18 years admitted to the Spanish National Healthcare System between 2016 and 2019. Mean costs per hospitalization episode were compared using a multivariable log-gamma generalized linear model adjusted by age, risk group and calendar year. Total annual hospitalization costs were estimated from population incidence rates (for RSV we used model-based rates reported in a published study due to the substantial under-ascertainment of cases) and the mean cost per episode. ICD-10 codes identified a total of 11,662 adults hospitalized with RSV and 79,319 with influenza. The mean length of stay was longer for RSV than for influenza in low-risk patients aged 60-79 years, moderate-risk patients (those with chronic medical conditions) aged ≥50 years and in high-risk (those with immunocompromising conditions) patients aged <80 years. There were no differences in intensive care unit (ICU) admission (except for higher admission in high-risk RSV patients aged 70-79 years), ICU stay or in-hospital case fatality rate. Mean costs per hospitalization episode were also similar: RSV €3870 (95 % CI 3773-3942) vs influenza €3888 (95 % CI 3836-3931). Total annual costs for RSV-attributable hospitalizations were estimated at M€194, twice than that of influenza (M€83). Annual costs increased by 11 % over the study period for RSV and by 47 % for influenza. In 2019, adults aged ≥60 years and ≥ 70 years contributed 91 % and 82 %, respectively, of the total RSV-attributable hospitalization costs in adults. RSV has a significant economic burden to the Spanish National Healthcare System, likely greater than influenza. Efficacious RSV vaccines and antivirals have the potential for high public health impact.

Laboratory Confirmation of Respiratory Syncytial Virus Infection Is Not Associated With an Increased Risk of Death in Adults With Acute Respiratory Illness

Background

Limited data have described the testing patterns and outcomes of adults (≥18 years) with acute respiratory illness (ARI) in the emergency department setting.

Methods

This prospective cohort study includes patients with ARI from a program sponsored by the Centers for Disease Control and Prevention entitled Respiratory Virus Laboratory Emergency Department Network Surveillance (RESP-LENS) from August 2021 until March 2024 (91 hospitals). Patients with ARIs were identified weekly by electronic surveillance for 1 or more of 130 ICD-10 codes that defined ARI. Patients were followed for 30 days for the primary outcomes of hospitalization and mortality. Testing for RSV with nasopharyngeal swabbing followed by reverse transcription polymerase chain reaction was done as part of usual care. Risk of 30-day mortality and RSV positivity was tested in a generalized estimating equation.

Results

From 1 210 394 patients with ARI, 345 185 (28.5%) adults underwent RSV testing, which was positive in 2.4%. In adults who were RSV+, the overall mortality rate was 1.9% as compared with 2.9% in adults who were RSV-. Mortality with RSV+ status increased with age ≥65 years to 3.8% (95% CI, 3.1%-4.5%). However, in the generalized estimating equation, RSV+ status was not associated with a higher rate of hospitalization (adjusted odds, 0.79; 95% CI, .75-.84) or 30-day mortality (odds, 0.62; 95% CI, .53-.74) relative to those who were RSV-. Age ≥65 years, incremental worsening of vital signs, male sex, and heart failure were independently associated with death.

Conclusions

Among adults with ARI presenting to an emergency department who were tested for RSV as part of their usual care, laboratory-confirmed RSV positivity was not associated with increased risk, including hospitalization, intensive care unit requirement, or death.

Respiratory syncytial virus: Characteristics, complications and mortality in immunocompetent versus immunocompromised hospitalized adults in Northern Denmark

BACKGROUND

Respiratory syncytial virus (RSV) is an increasingly well-known cause of severe respiratory symptoms in adults. We aimed to describe characteristics, complications and in-hospital mortality of adults admitted to hospital with RSV-related respiratory symptoms.

METHODS

Data were collected from electronic health records in the North Denmark Region for hospitalized adults diagnosed with RSV between April 1st - December 31st 2021. We collected data on characteristics, complications and mortality. Results were compared between immunocompromised and -competent patients.

RESULTS

We included 111 patients. Sixty-five percent had comorbidities and 20 % received immunosuppressive drugs. Fifty-three percent had bacterial pneumonia and 61 % needed oxygen support. Mortality was 12 %. There were no differences in complications between the compared groups.

CONCLUSION

Severe respiratory symptoms were frequent among RSV-patients. Bacterial co-infections were common in the study population and mortality was considerable, regardless of known immunosuppression, thus warranting thorough and early investigations in RSV-positive patients.

[Mechanism and significance of cell senescence induced by viral infection]

Virus-induced senescence (VIS) is a significant biological phenomenon, which is associated with declining immune function, accelerating aging process and causing aging-related diseases. A variety of common viruses, including RNA viruses (such as SARS-CoV-2), DNA viruses (such as herpesviruses and hepatitis B virus), and prions can cause VIS in host cells. The primary mechanisms include abnormal activation of the cGAS-STING signaling pathway, DNA damage response, and potential correlations with the integrated stress response due to intracellular phase separation. Viral infection and cellular senescence influence each other: cellular senescence serves as a defense to restrict viral replication and transmission, while some viruses exploit cellular senescence to enhance their infectivity and replication. Understanding the mechanisms of VIS is conducive to the development of therapeutic strategies for viral infections and promotion of healthy aging. However, there is lack of research on therapeutic targets and drug development in this field so far. Although senolytics may be effective for anti-senescent cells therapy, their efficacy for VIS needs evidence from further clinical trials. This article reviews the research progress on the connection between viral infection and cellular senescence, to provide insights for the prevention and treatment of aging related diseases.

Prevalence of Respiratory Syncytial Virus Infection in Hospitalized COPD Patients in Spain Between 2018-2022

BACKGROUND

Respiratory syncytial virus (RSV) infection is a common cause of hospital admission. The association between chronic obstructive pulmonary disease (COPD) exacerbation and RSV infection is not well studied.

OBJECTIVE

To analyze the hospitalizations of patients with COPD and RSV infection in Spain between 2018 and 2022.

METHODS

The data used were obtained from the Spanish Hospital Discharge Database. We selected subjects aged ≥40 years diagnosed with COPD, admitted to the hospital from 1 January 2018 to 31 December 2022. The COPD population that met the selection criteria was subdivided based on the presence of an ICD-10 code for RSV infection. To obtain comparable populations, for each subject with COPD and RSV infection, a subject without an RSV code was selected, with the COPD code in the same diagnostic position (1 to 20), as well as the same year of admission, sex, and age.

RESULTS

Among subjects aged ≥40 years, 1,429,288 were identified as having COPD, of whom 5673 also had RSV infection. The number of hospitalizations with COPD and RSV infection increased during the study period. The proportion of RSV infection among patients admitted for COPD increased significantly over time, from 0.32% in 2018 to 0.65% in 2022, p < 0.001. In-hospital mortality (IHM) increased over time, but the differences were not significant (6.23% in 2018 vs. 6.79% in 2022). Patients with COPD and RSV infection had, compared with those without RSV infection, a higher use of mechanical ventilation, both invasive (3.44% vs. 1.34%, p < 0.001) and noninvasive (8.09% vs. 4.51%, p < 0.001) and a higher proportion of intensive care unit (ICU) admission (7.21% vs. 3.9%, p < 0.001). After multivariate adjustment, a significant increase in IHM was found from 2018 to 2022 in subjects with and without RSV infection. The presence of RSV infection was associated with a higher mortality (OR 1.22; 95% CI 1.01-1.46).

CONCLUSIONS

The proportion of RSV infection among patients admitted for COPD increased significantly over time. Patients with COPD and RSV infection had, compared with those without RSV infection, a higher severity, a higher use of mechanical ventilation, and a higher proportion of ICU admission. The presence of RSV infection was associated with IHM. These results can help to identify patients at higher risk and make decisions to avoid the increased risk of hospitalization and mortality in this population.

The Saudi thoracic society guidelines for vaccinations in adult patients with chronic respiratory diseases

Adult patients with chronic respiratory diseases (CRDs) are considered high risk group who are more likely to experience worse clinical outcomes if they acquire viral or bacterial infections. Vaccination is the best preventive tool to reduce the risk of infection and disease occurrence and to reduce the level of severity of complications associated with the various vaccine-preventable infections. These guidelines were developed by the Saudi Thoracic Society task force to emphasize the critical importance of improving the vaccine coverage rates in adult patients with CRD. They are intended to serve as a reference for healthcare practitioners managing CRD patients. The guidelines aimed to review the current knowledge related to vaccination efficacy in adult patients with CRD, based on the recent evidence and recommendations. Integrating the administration of the recommended vaccines in routine healthcare, such as during outpatient visits or before hospital discharge, is crucial for improving the vaccination rates in high-risk patients. The key strategies to address this public health priority include simplifying vaccination guidelines to enhance their accessibility and implementation by healthcare providers, increasing awareness in both the patients and healthcare providers that vaccines are not only intended for children. Additional strategies include maintaining continuous surveillance and advance research to discover novel vaccines. This approach aims to expand the range of preventable diseases and improve overall health and well-being. Vaccine hesitancy remains a significant challenge that necessitates a clear understanding of the community concerns. Providing appropriate education and communication, as well as addressing these concerns, are the crucial steps toward improving vaccine acceptance and uptake. By implementing these guidelines and multifaceted strategies, healthcare systems can optimize vaccine coverage and protection for patients with CRD, reduce the burden of vaccine-preventable complications, and improve the clinical outcomes in this vulnerable population.

The Impact of Vaccination on COVID-19, Influenza, and Respiratory Syncytial Virus-Related Outcomes: A Narrative Review

Vaccination represents a core preventive strategy for public health, with interrelated and multifaceted effects across health and socioeconomic domains. Beyond immediate disease prevention, immunization positively influences downstream health outcomes by mitigating complications of preexisting comorbidities and promoting healthy aging. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza virus, and respiratory syncytial virus (RSV) are common respiratory viruses responsible for broad societal cost and substantial morbidity and mortality, particularly among at-risk individuals, including older adults and people with frailty or certain comorbid conditions. In this narrative review, we summarize the overall impact of vaccination for these 3 viruses, focusing on mRNA vaccines, each of which exhibits unique patterns of infection, risk, and transmission dynamics, but collectively represent a target for preventive strategies. Vaccines for COVID-19 (caused by SARS-CoV-2) and influenza are effective against the most severe outcomes, such as hospitalization and death; these vaccines represent the most potent and cost-effective interventions for the protection of population and individual health against COVID-19 and influenza, particularly for older adults and those with comorbid conditions. Based on promising results of efficacy for the prevention of RSV-associated lower respiratory tract disease, the first RSV vaccines were approved in 2023. Immunization strategies should account for various factors leading to poor uptake, including vaccine hesitancy, socioeconomic barriers to access, cultural beliefs, and lack of knowledge of vaccines and disease states. Coadministration of vaccines and combination vaccines, such as multicomponent mRNA vaccines, offer potential advantages in logistics and delivery, thus improving uptake and reducing barriers to adoption of new vaccines. The success of the mRNA vaccine platform was powerfully demonstrated during the COVID-19 pandemic; these and other new approaches show promise as a means to overcome existing challenges in vaccine development and to sustain protection against viral changes over time.A graphical abstract and video abstract is available with this article.

Favorable Nonclinical Safety Profile of RSVpreF Bivalent Vaccine in Rats and Rabbits

Background: Respiratory syncytial virus (RSV) infections usually cause mild, cold-like symptoms in most people, but are a leading infectious disease causing infant death and hospitalization and can result in increased morbidity and mortality in older adults and at-risk individuals. Pfizer has developed Abrysvo®, an unadjuvanted bivalent recombinant protein subunit vaccine containing prefusion-stabilized fusion (F) proteins representing RSV A and RSV B subgroups (RSVpreF). It is the only RSV vaccine approved for both maternal immunization to protect infants and active immunization of older adults (≥60 years) and 18-59-year-old individuals with high-risk conditions for prevention of RSV disease. Methods: Nonclinical safety studies, including a repeat-dose toxicity (RDT) study in rats and a combined developmental and reproductive toxicity (DART) study in rabbits, were conducted to support early clinical development. Study designs and parameters evaluated in these studies were consistent with principles and practices as outlined in relevant regulatory guidelines. RSVpreF bivalent vaccine, with or without Al(OH)3, was administered intramuscularly (IM) at 2× the human dose to animals in both studies. Results: Locally tolerated, reversible, inflammatory responses at the injection sites and the draining lymph nodes were observed as typical findings following vaccination. No effect of RSVpreF, with or without Al(OH)3, was observed on female fertility or on embryo-fetal or postnatal survival, growth, or development in the DART study. In both studies, robust immune responses to both RSV A and B antigens were observed, especially with the Al(OH)3 formulation. Conclusions: RSVpreF was well-tolerated both locally and systemically without any adverse effects on reproductive and developmental endpoints.

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.

Cost-effectiveness of the adjuvanted RSVPreF3 vaccine among adults aged ≥60 years in the United States

Respiratory syncytial virus (RSV) is a common cause of acute respiratory illness in individuals of all ages, with adults aged ≥60 years and adults with certain chronic conditions at increased risk of severe RSV-related outcomes. This study evaluates the cost-effectiveness of the adjuvanted RSVPreF3 vaccine versus no vaccine in adults aged ≥60 years in the United States (US). A multi-cohort Markov model was developed with a 5-year time horizon and 1-month cycle length to compare outcomes for no vaccination and one-time adjuvanted RSVPreF3 vaccination (assuming the same vaccination as for influenza vaccines). Clinical parameters (e.g., vaccine efficacy) were based on phase 3 clinical trial data over 3 seasons, with all other inputs obtained from public US sources and scientific literature. Outcomes included total and incremental quality-adjusted life year (QALY) losses and costs, as well as incremental cost-effectiveness ratios (ICERs). Sensitivity analyses were conducted to evaluate the sensitivity of results to inputs. In the base case, the model estimated that vaccinating 52.7 million adults aged ≥60 years with the adjuvanted RSVPreF3 vaccine once would result in 244,424 fewer QALY losses and an incremental societal cost of $4.5 billion over 5 years, with vaccination costs partially offset by reduced disease-related costs. From the societal perspective, adjuvanted RSVPreF3 vaccination resulted in an ICER of $18,430 per QALY gained. Results were relatively robust across sensitivity analyses and indicate that adjuvanted RSVPreF3 vaccination is a cost-effective option for the prevention of RSV in US adults aged ≥ 60 years, reducing the substantial burden within this population.

Design, synthesis and antiviral evaluation of triazole-linked 7-hydroxycoumarin-monoterpene conjugates as inhibitors of RSV replication

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory infections in babies across the world. Irrespective of progress in the development of RSV vaccines, effective small molecule drugs are still not available on the market. Based on our previous data we designed and synthesized triazole-linked coumarin-monoterpene hybrids and showed that they are indeed effective in inhibiting the RSV replication. The most effective compounds are active against both RSV serotypes, A and B, with IC50 in the low micromolar or submicromolar range of concentrations. These are the most active coumarin derivatives found so far. Compound 45 combining 3,7-dimethyloctane and cyclopentane-annealed coumarin fragments has a selectivity index of 160 for serotype A and 1147 for serotype B. According to the results of the time-of-addition experiments, the conjugates are active at the early stages of the virus cycle. Based on biological evaluation and molecular modeling data, RSV F protein is a possible target.

Annual public health and economic burden of medically attended respiratory syncytial virus illnesses among US adults

BACKGROUND

Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract disease (LRTD) among adults and can lead to serious morbidity and mortality; however, evidence on the magnitude of the public health and economic burden of adult RSV-LRTD is limited. This study was undertaken to project annual clinical outcomes and economic costs of medically attended RSV-LRTD among US adults, and to identify subgroups responsible for a disproportionate share of disease burden.

METHODS

Clinical outcomes of RSV-LRTD were projected for subgroups of US adults defined by age and comorbidity profile (with vs. without chronic/immunocompromising medical conditions) based on corresponding population sizes, episode (disease) rates, and case-fatality rates. Economic costs comprised medical (i.e., direct) costs and non-medical (i.e., indirect) costs of RSV-LRTD, and were generated based on numbers of episodes and unit costs in relation to setting of care, age, and comorbidity profile.

RESULTS

Among 265 million US adults aged ≥18 years in 2023, 6.5 million medically attended episodes of RSV-LRTD were projected to occur including 349,260 requiring hospitalization, 357,892 requiring an emergency department visit (not leading to hospitalization), and 5.8 million requiring other ambulatory care. Direct costs ($15.2 billion) and indirect costs ($9.7 billion) were projected to total $25.0 billion. Persons aged 60-99 years accounted for 31 % of the adult population and over 50 % of the economic burden of RSV-LRTD, while adults aged <60 years with chronic/immunocompromising medical conditions accounted for 10 % of the population and 27 % of the economic burden.

CONCLUSIONS

Annual burden of RSV-LRTD among US adults-especially older adults and those of all ages with underlying medical conditions-is substantial. Preventive measures, such as recently approved RSV vaccines, have the potential to yield important improvements in public and patient health, and to reduce the economic burden of RSV-LRTD from the US healthcare system and societal perspectives.

RSV vaccination as the optimal prevention strategy for older adults

Respiratory syncytial virus (RSV) is a respiratory virus that usually causes mild upper respiratory tract symptoms. However, it can lead to a severe lower respiratory tract disease in high-risk populations, with severe complications such as pneumonia and respiratory failure. RSV poses a significant public health threat not only to children, but also to adults, particularly those over 75 years of age and individuals with comorbidities. The high incidence and severity of RSV infections in these vulnerable groups highlights the urgent need for effective preventive strategies. Despite advancements in the clinical management of respiratory infections, preventing RSV remains a significant challenge. The symptoms of RSV are often underestimated and misdiagnosed due to their similarity to other respiratory infections like influenza and COVID-19. This leads to a substantial disease burden not only for patients but also for healthcare systems, due to increased hospitalizations and prolonged treatments. In recent years, there has been a significant progress in the development of RSV vaccines, offering new hope for disease prevention. Our aim is to promote RSV vaccination, emphasizing the importance of large-scale prevention efforts to enhance the quality of life for at-risk individuals and optimize healthcare resource allocation. This paper will report efficacy and safety data for the three main vaccines currently available for healthcare practitioners, providing a comprehensive and balanced overview of vaccine options and supporting informed decision-making by healthcare professionals and regulatory authorities.

RSV Disease Burden in Older Adults: An Italian Multiregion Pilot Study of Acute Respiratory Infections in Primary Care Setting, Winter Season 2022-2023

BACKGROUND

Respiratory syncytial virus (RSV) is a major cause of hospital admission in adults over 65, leading to severe complications and death. However, the disease burden in primary care for older adults in Europe is poorly understood. This pilot study aims to test a study protocol for evaluating the clinical burden of RSV in older adults in primary care settings in Italy.

METHODS

In the 2022-23 winter season, we designed a study on RSV burden in individuals over 65 with acute respiratory infections (ARIs) in Liguria, Apulia, and Tuscany, Italy. Recruited patients underwent nasopharyngeal swabs for RSV confirmation and provided epidemiological and clinical data. RSV-positive patients completed follow-up questionnaires after 14 and 30 days regarding their clinical conditions, healthcare utilization, and socio-economic impact.

RESULTS

We enrolled 152 patients with ARIs; 33 (21.7%) tested positive for RSV. The median disease duration was 14 days, with 3% hospitalized. Among RSV-positive patients, 87% received drug treatment, 52% of whom received antibiotics. After diagnosis, 74% required further GP consultations within 2 weeks. Additionally, 48% incurred extra costs. On day 30, 21% reported health complications or deterioration.

CONCLUSIONS

Our pilot study highlights the need for an ARIs surveillance system for older adults in primary care. This is crucial for defining vaccination strategies to reduce the disease burden on these patients and the healthcare system. Moreover, these data are essential for assessing costs and parameters for cost-effectiveness models, facilitating informed decisions in public health planning and resource allocation.

Integration of nanobiosensors into organ-on-chip systems for monitoring viral infections

The integration of nanobiosensors into organ-on-chip (OoC) models offers a promising advancement in the study of viral infections and therapeutic development. Conventional research methods for studying viral infection, such as two-dimensional cell cultures and animal models, face challenges in replicating the complex and dynamic nature of human tissues. In contrast, OoC systems provide more accurate, physiologically relevant models for investigating viral infections, disease mechanisms, and host responses. Nanobiosensors, with their miniaturized designs and enhanced sensitivity, enable real-time, continuous, in situ monitoring of key biomarkers, such as cytokines and proteins within these systems. This review highlights the need for integrating nanobiosensors into OoC systems to advance virological research and improve therapeutic outcomes. Although there is extensive literature on biosensors for viral infection detection and OoC models for replicating infections, real integration of biosensors into OoCs for continuous monitoring remains unachieved. We discuss the advantages of nanobiosensor integration for real-time tracking of critical biomarkers within OoC models, key biosensor technologies, and current OoC systems relevant to viral infection studies. Additionally, we address the main technical challenges and propose solutions for successful integration. This review aims to guide the development of biosensor-integrated OoCs, paving the way for precise diagnostics and personalized treatments in virological research.

Humoral Immunogenicity of mRNA-1345 RSV Vaccine in Older Adults

BACKGROUND

The mRNA-1345 vaccine demonstrated efficacy against respiratory syncytial virus (RSV) disease with acceptable safety in adults aged ≥60 years in the ConquerRSV trial. Here, humoral immunogenicity results from the trial are presented.

METHODS

This phase 2/3 trial randomly assigned adults (≥60 years) to mRNA-1345 50-µg encoding prefusion F (preF) glycoprotein (n = 17 793) vaccine or placebo (n = 17 748). RSV-A and RSV-B neutralizing antibody (nAb) and preF binding antibody (bAb) levels at baseline and day 29 postvaccination were assessed in a per-protocol immunogenicity subset (PPIS; mRNA-1345, n = 1515; placebo, n = 333).

RESULTS

Day 29 nAb geometric mean titers (GMTs) increased 8.4-fold against RSV-A and 5.1-fold against RSV-B from baseline. Seroresponses (4-fold rise from baseline) in the mRNA-1345 groups were 74.2% and 56.5% for RSV-A and RSV-B, respectively. Baseline GMTs were lower among participants who met the seroresponse criteria than those who did not. mRNA-1345 induced preF bAbs at day 29, with a pattern similar to nAbs. Day 29 antibody responses across demographic and risk subgroups were generally consistent with the overall PPIS.

CONCLUSIONS

mRNA-1345 enhanced RSV-A and RSV-B nAbs and preF bAbs in adults (≥60 years) across various subgroups, including those at risk for severe disease, consistent with its demonstrated efficacy in the prevention of RSV disease.

CLINICAL TRIALS REGISTRATION

NCT05127434.

Respiratory Syncytial Virus vs Influenza Virus Infection: Mortality and Morbidity Comparison Over 7 Epidemic Seasons in an Elderly Population

BACKGROUND

Respiratory syncytial virus (RSV) infection is gaining interest due to the recent development of vaccines but is still misdiagnosed in the elderly. The primary objective was to compare all-cause mortality at day 30. Secondary objectives were to compare clinical presentation and rates of consolidative pneumonia, hospitalization, and intensive care unit (ICU) admission.

METHODS

A single-center retrospective study was conducted in a French university hospital during 7 epidemic seasons including 558 patients aged ≥75 years: 125 with RSV and 433 with influenza (median age, 84.8 years).

RESULTS

Patients with RSV had more respiratory symptoms (wheezing, dyspnea) whereas patients with influenza had more general symptoms (fever, asthenia, myalgia). The following were higher in the RSV group: consolidative pneumonia (28.8% vs 17.2%, P = .004), hospitalization (83.2% vs 70%, P = .003), ICU admission (7.2% vs 3.0%, P = .034), and length of stay (median [IQR], 9 days [2-16] vs 5 days [0-12]; P = .002). Mortality rates at day 30 were comparable (9.6% vs 9.7%, P = .973).

CONCLUSIONS

This study included the largest cohort of patients infected with RSV aged >75 years documented in-depth thus far. RSV shares a comparable mortality rate with influenza but is associated with higher rates of consolidative pneumonia, hospitalization, ICU admissions, and extended hospital stays.

Hospitalization Following Outpatient Diagnosis of Respiratory Syncytial Virus in Adults

Importance

Respiratory syncytial virus (RSV) is a leading cause of acute respiratory tract infections among adults and is estimated to cause approximately 159 000 hospitalizations among adults aged 65 years and older in the US each year. Estimates of hospitalization among adults with outpatient medically attended RSV (MA-RSV) infections are required to design interventional studies that aim to prevent hospitalization.

Objective

To assess absolute risk of 28-day, all-cause hospitalization following outpatient MA-RSV infections in adults.

Design, Setting, and Participants

In this cohort study, data from 3 different deidentified databases containing electronic health records (EHR) linked to closed claims data (Optum's deidentified Integrated Claims-Clinical dataset, TriNetX Linked, and Veradigm Network EHR [VNEHR] database linked with claims) were analyzed separately across 6 RSV years (October 1, 2016, to September 30, 2022) in adults with commercial or government insurance. Outpatient (eg, clinics and emergency departments) MA-RSV infections were identified based on clinical laboratory data or RSV-specific International Statistical Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnosis codes. Data were analyzed from March 2023 to April 2024.

Main Outcomes and Measures

The main outcome was all-cause 28-day hospitalization following outpatient MA-RSV infections among all adults and a high-risk subgroup (defined as age ≥65 years or with asthma, chronic obstructive pulmonary disease [COPD], or congestive heart failure [CHF]).

Results

In this cohort study of 67 239 MA-RSV infections in adults (2771 from Optum, 7442 from TriNetX, and 57 026 from VNEHR), most occurred among females (62%-67%) and comorbidity prevalences were 20.0% to 30.5% for COPD, 14.6% to 24.4% for CHF, 14.6% to 24.4% for asthma; 14.0% to 54.5% of individuals were aged 65 years or older. The proportion hospitalized was 6.2% (95% CI, 5.3%-7.1%) in Optum, 6.0% (95% CI, 5.4% to 6.5%) in TriNetX, and 4.5% (95% CI, 4.3%-4.6%) in VNEHR. Among the high-risk subgroup, the proportion hospitalized was 7.6% (95% CI, 6.5%-8.9%) in Optum, 8.5% (95% CI, 7.6%-9.4%) in TriNetX, and 6.5% (95% CI, 6.2%-6.8%) in VNEHR.

Conclusions and Relevance

In this cohort study of adults with outpatient MA-RSV infections from 3 large deidentified US databases across 6 RSV seasons, approximately 1 in 20 adults experienced all-cause hospitalization within 28 days. The results of this study highlight the public health need for RSV prevention and treatment.

Severity of respiratory syncytial virus compared with SARS-CoV-2 and influenza among hospitalised adults ≥65 years

INTRODUCTION

Our aim was to estimate the risk of pneumonia, admission to intensive care unit (ICU) or death in individuals ≥65 years old admitted to hospital with RSV, compared to influenza or COVID-19.

METHODS

We included hospitalised patients from Severe Acute Respiratory Infection Surveillance in Spain between 2021-2024, aged ≥65 years, laboratory confirmed for RSV, influenza or SARS-CoV-2. Using a binomial regression with logarithmic link, we estimated the relative risk (RR) of pneumonia, ICU admission and in-hospital mortality, in patients with RSV compared to influenza or SARS-CoV-2, adjusting for age, sex, season and comorbidities. We stratified the estimates by vaccination status for influenza or SARS-CoV2.

RESULTS

Among patients unvaccinated for influenza or SARS-CoV-2, those with RSV had similar or lower risk of pneumonia [vs. influenza: RR= 0.91 (95% Confidence Interval: 0.72-1.16); vs. SARS-CoV-2: 0.81 (0.67-0.98)], ICU admission [vs. influenza: 0.93 (0.41-2.08); vs. SARS-CoV-2: 1.10 (0.61-1.99)] and mortality [vs. influenza: 0.64 (0.32-1.28); vs. SARS-CoV-2: 0.56 (0.30-1.04)]. Among the vaccinated, results were largely similar except for a higher risk of ICU admission with RSV [vs. influenza: 2.13(1.16-3.89); vs. SARS-CoV-2: 1.83 (1.02-3.28)] CONCLUSIONS: RSV presented similar or lower intrinsic severity than influenza or SARS-CoV2. Among vaccinated patients, RSV was associated to higher ICU-admission, suggesting the potential for preventive RSV vaccination.

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 aged ≥ 60 years with pulmonary diseases. However, more data are needed to understand how these vaccinations affect key clinical outcomes in individuals with pulmonary disease.

Short-Term Immunogenicity of Licensed Subunit RSV Vaccines in Residents of Long-Term Care Facilities (LTCF) Compared to Community-Dwelling Older Adults

OBJECTIVES

Phase 3 licensing trials for the recently approved respiratory syncytial virus (RSV) vaccines did not include many residents of long-term care facilities (LTCF). Our primary objective was to assess humoral immune responses in LTCF residents, aged 60 and older, to the RSV vaccines, and demonstrate noninferiority to antibody responses in community-dwelling (CD) adults who were representative of the phase 3 trial participants in whom the vaccines were highly efficacious.

DESIGN

Prospective non-randomized intervention trial of RSV vaccines in LTCF residents.

SETTING AND PARTICIPANTS

Research clinic and 2 LTCFs. Adults aged ≥60 years old, free of immunosuppression and planning to receive an RSV vaccine were eligible.

METHODS

LTCF and CD participants received either the GSK or Pfizer RSV vaccine in equal numbers. Blood was collected before and 30 days after vaccination. Total immunoglobulin (Ig)G to the prefusion F protein of RSV group A (FA) and B (FB), and neutralizing activity were measured, and geometric mean titer (GMT) and geometric mean fold rise (GMFR) calculated. Intercurrent respiratory illnesses were tracked.

RESULTS

A total of 76 LTCF residents and 76 CD adults were enrolled. Day 30 blood was unavailable from 3 residents and 3 had RSV infection and vaccination was deferred, leaving data for 76 CD and 70 LTCF adults for analysis. Serum IgG GMFR prefusion FA (9.9 vs 12.5, P = .14), prefusion FB (8.7 vs 11.0, P = .17) were not statistically different in CD and LTCF cohorts, respectively, and also equivalent for GMFR in viral neutralization titers (12.8 vs. 15.5, P = .32). As measured by GMT or GMFR, RSV vaccine responses of LTCF residents met noninferiority criteria compared with the CD cohort.

CONCLUSIONS AND IMPLICATIONS

This small immunobridging study demonstrates robust antibody responses to RSV vaccines in LTCF residents providing support for their use in this high-risk population.

Safety and immunogenicity of an mRNA-based RSV vaccine in Japanese older adults aged ≥60 years: A phase 1, randomized, observer-blind, placebo-controlled trial

BACKGROUND

Respiratory syncytial virus (RSV) represents a global health concern, including in older adults. This study assessed the safety and immunogenicity of mRNA-1345, an investigational mRNA RSV vaccine, in adults aged ≥60 years of Japanese descent.

METHODS

In this phase 1, randomized, observer-blind, placebo-controlled study, participants were randomized to receive one injection of mRNA-1345 100 μg or placebo. Solicited local and systemic adverse reactions (ARs) were collected within 7 days following injection. Unsolicited adverse events (AEs) were collected up to 28 days after injection; AEs of special interest, medically attended AEs, and serious AEs were collected through end of study. Immunogenicity was assessed at baseline and months 1, 2, 3, and 6 following injection.

RESULTS

Twenty-five adults of Japanese descent aged ≥60 years received one injection of mRNA-1345 100 μg (n = 21) or placebo (n = 4). mRNA-1345 was well-tolerated; the most common local and systemic solicited ARs were injection site pain, and fatigue and myalgia, respectively, which were generally mild to moderate and transient. No serious AEs were reported. Neutralizing (nAb) and binding (bAb) antibodies were detectable at baseline, consistent with prior RSV exposure. mRNA-1345 boosted RSV nAb titers and preF bAb concentrations 1 month post-injection (geometric mean fold rise: RSV-A nAb, 11.2; RSV-B nAb, 6.6; preF bAb, 9.1). Titers among mRNA-1345 recipients remained above baseline through 6 months.

CONCLUSIONS

mRNA-1345 100 μg was well-tolerated among older adults of Japanese descent and induced nAbs and bAbs which were durable through 6 months, supporting its continued development.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04528719.

Cost-Effectiveness of Bivalent Respiratory Syncytial Virus Prefusion F Vaccine for Prevention of Respiratory Syncytial Virus Among Older Adults in Greece

BACKGROUND/OBJECTIVES

To evaluate the health benefits, costs, and cost-effectiveness of vaccination with bivalent respiratory syncytial virus stabilized prefusion F vaccine (RSVpreF) for the prevention of lower respiratory tract disease caused by respiratory syncytial virus (RSV) in Greek adults 60 years of age and older.

METHODS

A Markov model was adapted to simulate lifetime risk of health and economic outcomes from the public payer's perspective over a lifetime horizon. Epidemiology, vaccine effectiveness, utilities, and direct medical costs (EUR, 2024) were obtained from published studies, official sources, and local experts. Model outcomes included the number of medically attended RSV cases, stratified by care setting (i.e., hospital, emergency department [ED], outpatient visits [OV]), and attributable RSV-related deaths, costs, life years (LY), quality-adjusted life-years (QALY), and incremental cost-effectiveness ratios (ICERs) of RSVpreF vaccination compared with no vaccination.

RESULTS

The model projected 258,170 hospitalizations, 112,248 ED encounters, 1,201,604 OV, and 25,463 deaths related to RSV in Greek older adults resulting in direct medical costs of EUR 1.6 billion over the lifetime horizon. Assuming RSV vaccination would reach the same coverage rates as pneumococcal and influenza programmes, 18,118 hospitalizations, 7874 ED encounters, 48,079 OV, and 1706 deaths could be prevented over the modelled time horizon. The health benefits associated with RSVpreF contributed to an incremental gain of 10,976 LYs and 7230 QALYs compared with no vaccination. The incremental analysis reported that vaccination with RSVpreF was estimated to be a cost-effective strategy resulting in ICERs of EUR 12,991 per LY gained, EUR 19,723 per QALY gained, and EUR 7870 per hospitalized RSV case avoided compared with no vaccination.

CONCLUSIONS

Vaccination with RSVpreF was a cost-effective strategy for the prevention of RSV disease in Greek adults over 60 years of age. The introduction of RSV vaccination can improve public health by averting RSV cases and deaths and has the potential to fulfil an unmet medical need.

Characteristics and outcomes of patients hospitalized for infection with Influenza A, SARS-CoV-2 or respiratory syncytial virus in the season 2023/2024 in a large German primary care centre

BACKGROUND

In addition to the persistence of SARS-CoV-2 infections, those with Influenza A/B and RSV have reappeared in 2022/23. To compare the development of prevalence, clinical outcomes and risk factors, we analysed data of the season 2023/24 from the same region/hospital as for 2022/23.

METHODS

Patients covering the whole age range with a positive polymerase chain reaction (PCR) test for SARS-CoV-2, Influenza A/B, RSV were included from the internal, neurological and paediatric units of the RoMed hospital Rosenheim, Germany/Bavaria, from August 1st 2023 to 29th February 2024.

RESULTS

Of 932 patients included, 912 showed single infections with SARS-CoV-2, Influenza A or RSV (47.9% female, median age 68.0 years; 52.9% SARS-CoV-2, 23.2% Influenza A, 21.8% RSV). Co-infections (2.0%) and Influenza B (0.1%) were negligible. In patients of age ≥ 18 years (n = 628, 68.5% SARS-CoV-2, 26.0% Influenza A, 5.6% RSV), patients with Influenza A were younger compared to SARS-CoV-2 (p < 0.001), with RSV similar to SARS-CoV-2. Heart failure and asthma were the most prevalent comorbidities for RSV, immunosuppression for Influenza A. Admission to Intensive Care Unit (ICU) occurred in 111 patients (17.0% of SARS-CoV-2, 17.2% Influenza A, 28.6% RSV), and 59 patients died (8.8% SARS-CoV-2, 8.6% Influenza A, 20.0% RSV). Low-flow oxygen supplementation and non-invasive ventilation (NIV) were most frequent for RSV (68.6% and 20.0%, respectively), oxygen demand upon admission for Influenza A (39.3%), without differences in high-flow oxygen supply or length of hospital stay. Among patients aged < 18 years (n = 284, 21.4% SARS-CoV-2, 18.0% Influenza A, 57.1% RSV), 15 were admitted to ICU (4.8% SARS-CoV-2, 3.8% Influenza A, 6.0% RSV); none of them died. Oxygen supply via high-flow, low-flow or upon admission was highest for RSV (23.8%, 70.2%, 21.4%, respectively), as well as the length of hospital stay.

CONCLUSION

Between 8/2023 to 2/2024, a large population of patients hospitalized due to respiratory tract infection, showed relative contributions of SARS-CoV-2, Influenza A or RSV similar to those in 2022/23. The findings underline that in both, adults and children, RSV posed a relatively higher clinical risk than Influenza A and SARS-CoV-2, though absolute numbers remained highest for SARS-CoV-2.

Respiratory Syncytial Virus-related Community Chronic Obstructive Pulmonary Disease Exacerbations and Novel Diagnostics: A Binational Prospective Cohort Study

Rationale: Respiratory syncytial virus (RSV) is a common global respiratory virus that is increasingly recognized as a major pathogen in frail older adults and as a cause of chronic obstructive pulmonary disease (COPD) exacerbations. There is no single test for RSV in adults that has acceptable diagnostic accuracy. Trials of RSV vaccines have recently shown excellent safety and efficacy against RSV in older adults; defining the frequency of RSV-related community infections and COPD exacerbations is important for vaccine deployment decisions. Objectives: This prospective study aimed to establish the frequency of outpatient-managed RSV-related exacerbations of COPD in two well-characterized patient cohorts using a combination of diagnostic methods. Methods: Participants were recruited at specialist clinics in London, United Kingdom, and Groningen, the Netherlands, beginning in 2017 and observed for three consecutive RSV seasons, during exacerbations, and at least twice yearly. RSV infections were detected by RT-PCR and serologic testing. Measurements and Main Results: A total of 377 patients with COPD attended 1,999 clinic visits and reported 310 exacerbations. There were 27 RSV-related exacerbations (8.7% of the total); of these, seven were detected only by PCR, 16 only by serology, and four by both methods. Increases in RSV-specific Nucleoprotein antibody were as sensitive as those in the antibody to Pre-Fusion or Post-Fusion for serodiagnosis of RSV-related exacerbations. Conclusions: RSV is associated with 8.7% of outpatient-managed COPD exacerbations in this study. Antibodies to RSV Nucleoprotein may have diagnostic value and are potentially important in a vaccinated population. The introduction of vaccines that prevent RSV is expected to benefit patients with COPD.

Induction of neutralizing antibody responses by AAV5-based vaccine for respiratory syncytial virus in mice

Introduction

Respiratory Syncytial Virus (RSV) is a significant cause of respiratory illnesses worldwide, particularly in infants and elderly individuals. Despite the burden RSV imposes, effective preventive measures are limited. The research application of adeno-associated virus (AAV) in vaccine platforms has been expanding, and its potential in prevention and treatment has garnered much attention.

Methods

In this study, we explored the potential application of a recombinant adeno-associated virus 5 (rAAV5) vector-based RSV vaccine, focusing on the expression of the pre-fusion (Pre-F) protein structure. Through intramuscular immunization in mice. The immunogenicity of the vaccine was evaluated in Balb/c mice immunized intramuscularly and intranasal, respectively.

Results

The rAAV5-RSV-Fm vaccine demonstrated positive humoral and induced antibody titers against RSV strains A and B for up to 120 days post-immunization. Notably, intranasal administration also elicited protective antibodies. Characterization studies confirmed the ability of the vac-cine to express the Pre-F protein and its superior immunogenicity compared to that of full-length F protein.

Conclusion

These findings underscore the potential application of rAAV5 vector platforms in RSV vaccine development and further investigation into their protective efficacy is warranted.

Comparative study on the epidemiological characteristics and hazards of respiratory syncytial virus and influenza virus infections among elderly people

OBJECTIVE

To investigate the epidemiological characteristics and infections of respiratory syncytial virus (RSV) and influenza viruses in hospitalized elderly patients with respiratory tract infections in Suzhou City, China, and to compare the differences in clinical characteristics and economic burden associated with these two infections.

METHODS

In this prospective study, pathogenetic testing and clinical data for hospitalized patients aged 60 years and older with respiratory tract infections were collected in five hospitals through stratified cluster sampling from December 2023 to May 2024. Comparative study on epidemic characteristics, clinical features and costs of cases who infected RSV alone and influenza alone were conducted.

RESULTS

Among 1,894 cases included, the RSV positivity rate was 5.91% during the 2023-2024 winter-spring season, while the influenza positivity rate was 9.61%. RSV-B was the predominant subtype of RSV, and influenza A (primarily H3N2) was the dominant strain among the influenza-positive cases. Compared with cases infected influenza virus alone, those infected RSV alone had lower occurrence frequency of fever (18.8% vs. 35.7%, P = 0.004), higher occurrence frequency of complications of lower respiratory tract infections (70.8% vs. 54.8%, P = 0.011), higher direct medical costs ($996.2 vs. $841.1, P = 0.017) and total costs ($1019.7 vs. $888.1, P = 0.036). RSV single infection is more common in female cases (P = 0.007) and diabetic cases (P = 0.007) than influenza virus single infection.

CONCLUSIONS

During the winter and spring months, RSV is the second most common pathogen after influenza virus among older adults hospitalized for respiratory infections in Suzhou, China. Patients infected RSV are more likely to develop complications with lower respiratory tract infections and have higher medical costs than the influenza. RSV infection in the elderly should be emphasized, especially in female patients and diabetic patients.

Clinical symptoms, comorbidities and health outcomes among outpatients infected with the common cold coronaviruses versus influenza virus

BACKGROUND

Common cold coronaviruses (ccCoVs) and influenza virus are common infectious agents causing upper respiratory tract infections (RTIs). However, clinical symptoms, comorbidities, and health effects of ccCoV infection remain understudied.

METHODS

A retrospective study evaluated 3,935 outpatients with acute upper RTI at a tertiary teaching hospital. The presence of ccCoV and influenza virus was determined by multiplex molecular assay. The demographic, clinical symptoms, and health outcomes were compared between patients with ccCoV (n = 205) and influenza (n = 417) infections. Multivariable logistic regression was employed to evaluate predictors and health outcomes over a one-year follow-up.

RESULTS

Sore throat, nasal discharge, headache, and myalgia were more predominant in ccCoV infection; fever was common in influenza. Most patients reported moderate symptoms severity (49.8% ccCoV, 56.1% influenza). Subsequent primary care visits with symptoms of RTI within a year were comparable for both infections (27.3% ccCoV vs. 27.6% influenza). However, patients with influenza reported increased primary care visits for non-RTI episodes and all-cause hospital admission. Baseline comorbidities were associated with increased primary care visits with symptoms of RTI in either ccCoV (adjusted odds ratio [aOR] 2.5; 95% confidence interval [CI] 1.1-5.9; P = 0.034) or influenza (OR 1.9; 95% CI 1.1-3.1; P = 0.017) infections, due probably to the dysregulation of the host immune response following acute infections. In patients infected with influenza infection, dyslipidemia was a predictor for subsequent primary care visits with symptoms of RTI (unadjusted OR 1.8; 95% CI 1.0-3.0; P = 0.040).

CONCLUSIONS

Both influenza and ccCoV infection pose significant disease burden, especially in patients with comorbidities. The management of comorbidities should be prioritized to mitigate poor health outcomes in infected individuals.

Immediate post-discharge care among US adults hospitalized with respiratory syncytial virus infection

BACKGROUND

Respiratory Syncytial Virus (RSV) is an important pathogen causing acute respiratory illnesses in adults. RSV infection can lead to severe outcomes, including hospitalizations and even death. Despite the increased recognition of the burden in older adults, immediate post-discharge care needs among adults hospitalized with RSV are not well characterized and have not been compared to other serious medical conditions (such as influenza, acute myocardial infarction (MI), and stroke) for which there have been long-standing disease prevention efforts.

OBJECTIVES

This study aims to describe the immediate post-discharge care needs among adults hospitalized with RSV in the United States and descriptively compare it to those hospitalized with influenza, acute MI, or stroke.

DESIGN

Retrospective observational cohort study.

PATIENTS

Adults aged ≥ 18 years, hospitalized with a primary diagnosis of RSV, influenza, acute MI, or stroke from January 01, 2016, to December 31, 2019, were identified from the Premier Healthcare Database using the International Classification of Diseases (ICD-10) codes.

MAIN MEASURES

Immediate post-discharge care was categorized into three different levels of care based on the discharge dispositions. Descriptive analyses were performed.

KEY RESULTS

In total, 3,629 RSV, 303,577 influenza, 388,682 acute MI, and 416,750 stroke hospitalizations were identified, the majority occurred among patients aged ≥ 65 years. Professional home care needs were the highest for RSV hospitalizations (19.1%), followed by influenza (17.7%), stroke (15.4%), and acute MI (9.8%). Additionally, institutional care needs immediately following discharge were similar for RSV, influenza, and acute MI hospitalizations (14.2%, 15.8%, and 14.1%, respectively).

CONCLUSIONS

Immediate post-discharge care needs among adults hospitalized with RSV, especially in older adults, can be considerable and comparable to influenza and acute MI discharges. With recently approved RSV vaccines, efforts to increase vaccination in older adults are needed to prevent RSV and associated healthcare consequences.

A multi-center study on genetic variations in the fusion protein of respiratory syncytial virus from children with Acute Lower Respiratory Tract Infections in China during 2017-2021

Respiratory syncytial virus (RSV) is a significant cause of acute lower respiratory tract infection (ALRTI) in children under five years of age. Between 2017 and 2021, 396 complete sequences of the RSV F gene were obtained from 500 RSV-positive throat swabs collected from ten hospitals across nine provinces in China. In addition, 151 sequences from China were sourced from GenBank and GISAID, making a total of 549 RSV F gene sequences subjected to analysis. Phylogenetic and genetic diversity analyses revealed that the RSV F genes circulating in China from 2017 to 2021 have remained relatively conserved, although some amino acids (AAs) have undergone changes. AA mutations with frequencies ≥ 10% were identified at six sites and the p27 region: V384I (site I), N276S (site II), R213S (site Ø), and K124N (p27) for RSV A; F45L (site I), M152I/L172Q/S173 ​L/I185V/K191R (site V), and R202Q/I206M/Q209R (site Ø) for RSV B. Comparing mutational frequencies in RSV-F before and after 2020 revealed minor changes for RSV A, while the K191R, I206M, and Q209R frequencies increased by over 10% in RSV B. Notably, the nirsevimab-resistant mutation, S211N in RSV B, increased in frequency from 0% to 1.15%. Both representative strains aligned with the predicted RSV-F structures of their respective prototypes exhibited similar conformations, with low root-mean-square deviation values. These results could provide foundational data from China for the development of RSV mAbs and vaccines.

Efficacy of anti-RSV vaccination in preventing respiratory syncytial virus disease and severe illness in older adults: a systematic review of randomized controlled trials

PURPOSE

Several vaccines against respiratory syncytial virus (RSV) are being developed. The objective of this systematic review is to determine the efficacy of these vaccines in preventing RSV disease in adults over 60 years of age, especially regarding severe illness.

METHODS

We researched MEDLINE, CENTRAL, Scopus, medRxiv, bioRxiv and ClinicalTrials.gov until April/2024. Randomized controlled trials studying an anti-RSV vaccine in adults above 60 years and reporting RSV-related acute respiratory infection/disease (ARI/ARD), lower respiratory tract infection/disease (LRTI/LRTD) and severe LRTI/LRTD were included. Vaccine efficacy was calculated as ([1 - risk ratio] × 100). Risk of bias and certainty of evidence were assessed by RoB2 tool and GRADE approach. The meta-analytical relative risk of ARI/ARD and LRTI/LRTD was estimated, with a subgroup analysis performed according to the vaccine type. The random effects model was used.

RESULTS

We included seven studies, five addressing prefusion vaccines and two regarding non-prefusion ones. The number of RSV-related LRTI/LRTD cases was reduced by vaccination, with a relative risk of 0.39 [CI 95% 0.22 to 0.69] and a vaccine efficacy of 61%. Considering the subgroup of prefusion vaccines alone, there is a relative risk of 0.27 [CI 95% 0.19 to 0.36] for LRTI/LRTD and a vaccine efficacy of 73%. ARI/ARD incidence presented a similar pattern. Only one trial reports results for severe LRTI/LRTD, with a vaccine efficacy of 94.1% [95% CI 62.4 to 99.9].

CONCLUSIONS

Prefusion anti-RSV vaccines are efficacious in the prevention of LTRI/LTRD and ARI/ARD cases. More studies regarding severe LTRI/LTRD are necessary in the future.

Clinical Manifestations and Outcomes in Adults Hospitalized With Respiratory Syncytial Virus and Influenza a/B: A Multicenter Observational Cohort Study

Background

Respiratory syncytial virus (RSV) and influenza cause significant health challenges, particularly for individuals with comorbid conditions and older adults. However, information on the clinical manifestations and outcomes of adults hospitalized with RSV in Europe remains limited.

Methods

This multicenter observational cohort study of adults hospitalized with RSV or influenza A or B from March 2016 to April 2020 investigated the clinical manifestations, mortality risk factors, and association with 90-day mortality rates by logistic regression analysis after adjustment for covariates.

Results

Of 988 patients hospitalized with either virus, 353 had RSV, 347 had influenza A, and 288 had influenza B infection. Patients with RSV, compared with those with influenza A or B, were more likely to have comorbid conditions (83% for RSV vs 72% for influenza A [P = .03] and 74% for influenza B [P = .001]) or pneumonia (41% vs 29% [P = .03] and 24% [P < .001], respectively). After adjustment for covariates, RSV infection was associated with an increased all-cause mortality rate within 90 days compared with influenza B (odds ratio, 2.16 [95% confidence interval, 1.20-3.87]; P = .01) but not influenza A (1.38 [.84-2.29]; P = .21). Increasing age and present pneumonia were identified as independent mortality risk factors in patients with RSV.

Conclusions

Older adults hospitalized with RSV infections are at a higher risk of dying within 90 days of hospitalization than patients admitted with influenza B but at a similar risk as those admitted with influenza A, emphasizing the detrimental effects and severity of older patients being infected with RSV. Our findings underscore the need for strategic testing and vaccination approaches to mitigate the impact of RSV among older adults.