Global Disease Burden Estimates of Respiratory Syncytial Virus-Associated Acute Respiratory Infection in Older Adults in 2015: A Systematic Review and Meta-Analysis

Development and evaluation of ELISA serological immunoassays for influenza and respiratory syncytial viruses

INTRODUCTION

Respiratory syncytial virus (RSV) and influenza are major causes of respiratory infections globally. Although vaccines are available, serological tools to assess population-level immunity and maternal antibody transfer remain limited. This study aimed to develop and evaluate ELISA assays for detecting anti-RSV and anti-influenza antibodies as a basis for future maternal-fetal immunity research.

MATERIALS AND METHODS

In this study, we designed ELISA immunoassays using various influenza and RSV antigens. Sensitivity and specificity were calculated using sera from presumed seronegative infants and seropositive adults.

RESULTS

The influenza vaccine-based ELISA achieved 98.3 % sensitivity and 100 % specificity. The pre-fusion F protein of RSV (Arexvy®) showed 97.5 % sensitivity and 97.4 % specificity. Other antigen combinations performed less optimally.

DISCUSSION

These ELISA assays are scalable tools for seroepidemiological and maternal transfer studies. Future work will include correlation with neutralizing antibodies and paired maternal-infant analyses.

Addressing the Underestimated Burden of RSV in Older Adults in Europe: Epidemiology, Surveillance Gaps, and Public Health Implications

BACKGROUND/OBJECTIVES

Respiratory Syncytial Virus (RSV) is a leading cause of Lower Respiratory Tract Infections (LRTIs), posing a serious threat to vulnerable populations. Although growing evidence highlights its significant impact on older adults, RSV surveillance and data collection remain largely focused on children, underestimating the burden in older and high-risk adults. This review aims to synthesize current evidence on the epidemiological and clinical impact of RSV in older adults in Europe, assess existing surveillance strategies, and identify gaps to guide targeted public health responses.

METHODS

A two-phase research strategy was adopted. First, a comprehensive review of studies published between 2015-2025 was conducted via PubMed, focusing on the RSV burden in high-risk and elderly populations in Europe. Second, a structured web screening was performed to assess the status of existing RSV surveillance systems, focusing on eight selected European countries.

RESULTS

The review reported RSV prevalence rates ranging from 1% to 64.7% among older adults, with a high prevalence of comorbidities that exacerbate disease severity. Hospitalization rates varied between 12.6-55.9%, while mortality ranged from 2.15% to 13%, reaching up to 36% in intensive care settings. Surveillance systems for adult RSV infections across Europe remain limited and fragmented, with only 37.5% (3/8) of analyzed countries having dedicated surveillance for adults.

CONCLUSIONS

RSV represents a substantial and underrecognized threat to older adults, with significant clinical and healthcare implications. Strengthening surveillance, standardizing data collection, and ensuring equitable access to newly available preventive measures are urgent priorities to reduce the disease burden, protect vulnerable populations, and support resilient health systems against future health challenges.

Incidence of common respiratory pathogens among patients with severe acute respiratory infection during COVID-19 pandemic in Egypt

Severe Acute Respiratory Infection poses a significant threat to human health being a major cause of morbidity and mortality. The rate of co-infection among the underlying pathogens is unknown. During COVID-19 pandemic, reports for respiratory pathogens co-circulations in developing countries were limited. Identification of respiratory pathogens is paramount for effective patient management as early detection decreases the risk of mortality and morbidity. This is the first report to investigate the incidence of respiratory pathogens co-infection among patients with SARI during COVID-19 pandemic in Egypt. Clinically SARI patients were recruited from October 2020 to June 2022. Nasopharyngeal swabs were collected to detect SARS-CoV-2 followed by 33 respiratory pathogens identification using RT-PCR. Of 599 samples tested, 27% (158/599) patients were positive for COVID-19, in which 75.9% (120/158) patients were co-infected with other respiratory pathogens. In total, 31 pathogens were identified with a detection rate of 75% (450/599) among positive and negative COVID-19 patients. Bacterial co-infections rate was 39%, in which Klebsiella pneumoniae (5.3%) is the most common, while viral co-infections rate was 61%, in which Human Coronavirus HKU1 (6.2%) is the most common. Adenovirus, human rhinovirus and RSV were only detected in 70/11.7%, 50/8.3% and 41/6.8% of cases, respectively. Early detection and management of respiratory pathogens co-infection are crucial for effective patient management and preparedness for future pandemics.

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 underlie 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 related 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.

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.

Unveiling the Spectrum of Respiratory Syncytial Virus Disease in Adults: From Community to Hospital

BACKGROUND

Respiratory syncytial virus can cause severe disease in the older adult population. Three vaccines for RSV are currently market approved but the risk of RSV-hospitalization in (older) adults from a community level remains elusive. We aimed to estimate the risk of RSV-hospitalization and characterize the patients that end up in hospital.

METHODS

We manually analyzed records of adults aged ≥ 20 with RSV-infection between 2022 and 2024 in three hospitals in the Netherlands. These hospitals implemented routine RSV-testing at emergency departments. Using population-based data in combination with the in-hospital data, we estimated the population risk of RSV-hospitalization. Hospital records were analyzed to characterize the role RSV played in their course of disease.

RESULTS

We analyzed 709 RSV cases of whom 503 (70.9%) were hospitalized. Five hundred twenty-six patients were ≥ 60, and 183 were < 60 years of age. The population RSV-hospitalization rate was 6-20 per 100.000 patients aged 20-59 years and 43-236 per 100.000 for those ≥ 60. The highest risks were observed in those with COPD (1702 per 100.000) and with congestive heart disease (2383 per 100.000). RSV caused clinically relevant infection in 88% of hospitalized cases but was only mentioned using specific ICD-codes in 4.4%. Comorbidity was prevalent (88.5%) and exacerbation of underlying disease caused of 46.3% of RSV-related hospital admissions. ICU admittance was 11.2% and in-hospital mortality was 8.1%.

CONCLUSION

The risk of RSV-hospitalization from the community is low but is increased substantially in those with underlying disease. RSV is often clinically relevant in hospitalized patients by causing exacerbation of underlying disease but is infrequently mentioned in specific ICD-codes.

Relationship Between Frailty and Respiratory Syncytial Virus Infection in Hospitalized Older Adults

Background

This study aimed to evaluate the impact of frailty on clinical outcomes and disease severity of respiratory syncytial virus (RSV) infection in older adults using data from the CIRN SOS Network (Serious Outcomes Surveillance Network; Canadian Immunization Research Network).

Methods

This cohort study used data from the CIRN SOS Network collected during the 2012-2013, 2013-2014, and 2014-2015 influenza seasons. Patients aged ≥50 years who were hospitalized for acute respiratory illness were tested for RSV by multiplex reverse transcription-polymerase chain reaction. The analysis focused on frailty to assess its association with RSV disease severity and clinical outcomes. Frailty was categorized as nonfrail, prefrail, and frail according to validated cutoffs based on baseline frailty index.

Results

Among 365 older adults hospitalized for RSV-related acute respiratory infections, most were classified as frail (61.1%), with fewer classified as prefrail (28.5%) or nonfrail (10.4%). Frailty was significantly associated with severe RSV outcomes, such as prolonged hospitalization and increased oxygen therapy requirements. Specifically, frail patients experienced longer hospitalizations and higher intensive care unit admission rates, with an odds ratio of 3.48 (95% CI, 1.30-9.12) for the association between frailty and severe disease. While RSV types A and B showed no significant differences in clinical outcomes, chronic obstructive pulmonary disease and chronic kidney disease emerged as factors associated with disease severity, alongside frailty.

Conclusions

Frailty is an important predictor of RSV severity in older adults and is associated with longer hospital stays and increased health care needs. This highlights the need to consider frailty in RSV vaccine and therapeutic trials and suggests the potential benefits of interventions and public health and programmatic messaging tailored to older adults living with frailty.

Smartphone-based mobile digital pressure sensor for quantitative point-of-care testing of respiratory syncytial virus infection

Respiratory syncytial virus (RSV) is a major cause of acute respiratory tract infections in infants and elderly individuals, leading to hospitalisation and potentially fatal outcomes, posing a serious threat to global health and economy. This study proposes a smartphone-based mobile digital pressure sensor (smartphone-MDPS) for the quantitative detection of the RSV fusion protein (RSV-F) in clinical nasopharyngeal samples. The smartphone-MDPS utilized two monoclonal antibodies (mAbs) specific to the F protein, of which mAb1 was conjugated with Au@PtNPs (Au@PtNPs-mAb1) as the detection antibody and mAb2 was coupled with magnetic beads (MB-mAb2) as a coating antibody to establish a novel sandwich immunoassay. During the immune reaction, the substrate H2O2 was catalyzed to release O2 gas by the Au@PtNPs nanozyme within the Au@PtNPs-mAb1-RSV-F-mAb2-MB immunocomplexes. The pressure intensity of O2 was measured using a mobile digital pressure sensor and transmitted wirelessly to a smartphone application for analysis. The programming codes for the sensor module and Android app were developed considering the performance requirements of the smartphone-MDPS. With a quantitation range of 0.09-1.953 ng/mL, the system had a limit of quantitation (LOQ) of 0.09 ng/mL and a limit of detection (LOD) of 0.03 ng/mL. When nasopharyngeal samples from 27 patients with RSV infection and 46 healthy individuals were tested, the smartphone-MDPS and enzyme-linked immunosorbent assays (ELISA) exhibited 100 % positivity and specificity as well as a strong correlation coefficient (R2 = 0.991) for quantitative measurements between these two assays. In conclusion, the smartphone-MDPS has high portability, affordability, efficiency, sensitivity, and specificity, making it a promising immunoassay for quantitative point-of-care testing of RSV infection.

Insights in the RSV L polymerase function and structure

Respiratory syncytial virus (RSV) continues to have a large medical and economic impact worldwide, mainly in infants, elderly, and immunocompromised patients. While several vaccines and prophylactic antibodies are now available, effective treatment options are still needed. A highly interesting target for treatment is the replication process of the virus, in which the viral polymerase complex is critical. A critical protein of this complex is the RSV large (L) protein, which harbors multiple enzymatic functions that are all interesting targets for antiviral drug discovery. Unfortunately, not all structural parts of this L protein are currently resolved, which makes antiviral drug design and optimization challenging. In this review, an overview is given of current knowledge on the RSV L structure. Furthermore, a comparison is made between the L proteins of RSV and human metapneumovirus (hMPV), which, based on their sequence similarity, could shed light on missing structural gaps. New insights into the RSV and hMPV L protein structures are given, by modeling unresolved domains with AlphaFold2 and Alphafold3. While more structural studies are needed to confirm the modeling data, there is clearly potential for development of treatments targeting the L protein, for RSV and closely related viruses.

Risk analysis for outpatient experimental infection as a pathway for affordable RSV vaccine development

Controlled human infection models (CHIMs) are an important tool for accelerating clinical development of vaccines. CHIM costs are driven by quarantine facilities but may be reduced by performing CHIM in the outpatient setting. Furthermore, outpatient CHIMs offer benefits beyond costs, such as a participant-friendly approach and increased real-world aspect. We analyze safety, logistic and ethical risks of respiratory syncytial virus (RSV) CHIM in the outpatient setting. A review of the literature identified outpatient CHIMs involving respiratory pathogens. RSV transmission risk was assessed using data from our inpatient and outpatient RSV CHIMs (EudraCT 020-004137-21). Fifty-nine outpatient CHIMs using RSV, Streptococcus pneumoniae, rhinovirus, and an ongoing Bordetella Pertussis outpatient CHIM were included. One transmission event was recorded. In an inpatient RSV CHIM, standard droplet and isolation measures were sufficient to limit RSV transmission and no symptomatic third-party transmission was measured in the first outpatient RSV CHIM. Logistic and ethical advantages support outpatient CHIM adoption. We propose a framework for outpatient RSV CHIM with risk mitigation strategies to enhance affordable vaccine development.

Prevention of respiratory syncytial virus disease across the lifespan in Italy

Respiratory syncytial virus (RSV) causes substantial morbidity and mortality across the lifespan, with the highest burden seen in infants and older adults. Recently approved immunizing agents, including long-acting neutralizing monoclonal antibodies and a maternal vaccine for passive immunization of newborns, and three vaccines for adults aged 60 years and older who are vulnerable to RSV disease, have the potential to prevent severe RSV-associated disease if implemented successfully. The use of these agents will be implemented in some Italian regions over the next few months, although no consistent timelines or decisions for adoption at the national level are expected. A multidisciplinary group of experts in neonatology, obstetrics and gynecology, respiratory medicine, geriatric medicine, hygiene, and public health reviewed the evidence on RSV prevention and present here their considerations on implementing an RSV prevention strategy in Italy. Given the associated disease burden, it is essential to move quickly to deploy these agents in vulnerable populations, enhance surveillance to accurately detect/predict seasonal trends in RSV activity and measure the impact of prevention strategies. Continuing research combined with widespread use of more sensitive testing is needed to identify vulnerable populations and risk factors. Policies are needed to support these preventive measures in the Italian healthcare system, and access must be accompanied by educational initiatives and advocacy to promote acceptance by HCPs and the target population.

General practice antibiotic prescriptions attributable to respiratory syncytial virus by age and antibiotic class: an ecological analysis of the English population

BACKGROUND

Respiratory syncytial virus (RSV) may contribute to a substantial volume of antibiotic prescriptions in primary care. However, data on the type of antibiotics prescribed for such infections are only available for children <5 years in the UK. Understanding the contribution of RSV to antibiotic prescribing would facilitate predicting the impact of RSV preventative measures on antibiotic use and resistance. The objective of this study was to estimate the proportion of antibiotic prescriptions in English general practice attributable to RSV by age and antibiotic class.

METHODS

Generalized additive models examined associations between weekly counts of general practice antibiotic prescriptions and laboratory-confirmed respiratory infections from 2015 to 2018, adjusting for temperature, practice holidays and remaining seasonal confounders. We used general practice records from the Clinical Practice Research Datalink and microbiology tests for RSV, influenza, rhinovirus, adenovirus, parainfluenza, human metapneumovirus, Mycoplasma pneumoniae and Streptococcus pneumoniae from England's Second Generation Surveillance System.

RESULTS

An estimated 2.1% of antibiotics were attributable to RSV, equating to an average of 640 000 prescriptions annually. Of these, adults ≥75 years contributed to the greatest volume, with an annual average of 149 078 (95% credible interval: 93 733-206 045). Infants 6-23 months had the highest average annual rate at 6580 prescriptions per 100 000 individuals (95% credible interval: 4522-8651). Most RSV-attributable antibiotic prescriptions were penicillins, macrolides or tetracyclines. Adults ≥65 years had a wider range of antibiotic classes associated with RSV compared with younger age groups.

CONCLUSIONS

Interventions to reduce the burden of RSV, particularly in older adults, could complement current strategies to reduce antibiotic use in England.

Estimation of respiratory syncytial virus-associated hospital admissions in five European countries: a modelling study

Background

Respiratory syncytial virus (RSV) can cause severe disease, notably among infants, older adults, and individuals with comorbidities. Non-systematic testing and differences in coding practices affect direct measures of the hospital disease burden. We aim to tackle this issue and estimate RSV-associated respiratory hospital admissions through time series modelling of hospital admissions.

Methods

The number of RSV hospital admissions in Denmark, England, Finland, the Netherlands, and Spain were estimated with attribution analyses, using age-specific respiratory tract infection (RTI) admissions combined with virological data, both from routinely collected healthcare data. Analyses covered the years 2016-2023.

Findings

The attributed incidence of RSV per 100,000 children 0-2 months ranged from 1715 in Denmark to 3842 in England. In older adults, substantial differences in the incidence of ICD-10 coded RSV hospitalisations were found, while the attributed RSV incidence was more comparable, ranging from approximately 100 per 100,000 in adults 65-74 years to 200 per 100,000 persons 75-84 years and 500 per 100,000 persons 85 years and older.

Interpretation

RSV-attributed time series exhibit a high degree of synchronicity between participating countries, suggesting that this method for attribution addresses the known issues with underdiagnosis and misclassification. In the older age groups, a substantial proportion of RTI hospitalisations is attributed to RSV, underscoring the relevance of RSV as a cause of severe respiratory infections.

Funding

This project has received funding from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement 101034339. This Joint Undertaking receives support from the European Union's Horizon 2020 research and innovation programme and EFPIA.

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.

Safety and immunogenicity of mRNA-1345 RSV vaccine coadministered with an influenza or COVID-19 vaccine in adults aged 50 years or older: an observer-blinded, placebo-controlled, randomised, phase 3 trial

BACKGROUND

Coadministration of a respiratory syncytial virus (RSV) vaccine with seasonal influenza or SARS-CoV-2 vaccines could reduce health-care visits and increase vaccination uptake in older adults who are at high risk for severe respiratory disease. The RSV mRNA-1345 vaccine demonstrated efficacy against RSV disease with acceptable safety in the ConquerRSV trial in adults aged 60 years and older. We aimed to evaluate the safety and immunogenicity of mRNA-1345 coadministered with a seasonal influenza vaccine or SARS-CoV-2 mRNA vaccine.

METHODS

We conducted a two-part, phase 3, observer-blinded, placebo-controlled, randomised trial in medically stable adults aged 50 years or older in the USA. In part A, participants were randomly assigned in a 7:10:10 ratio to receive 50 μg mRNA-1345 plus placebo (0·9% sodium chloride) or coadministered with 60 μg of a standard-dose quadrivalent inactivated influenza vaccine (SIIV4), or SIIV4 plus placebo. In part B, participants were randomly assigned in a 1:1:1 ratio to receive 50 μg mRNA-1345 plus placebo or coadministered with 50 μg SARS-CoV-2 mRNA-1273.214 (bivalent [Wuhan-Hu-1 plus omicron BA.1]), or mRNA-1273.214 plus placebo. Random allocation in both parts was stratified by age group (50-59 years, 60-74 years, and ≥75 years) and used interactive response technology. The coprimary objectives in each part were safety in the safety set throughout the study and non-inferiority for six immunogenicity endpoints in the per-protocol set comparing coadministered versus individual vaccines on day 29. Immunogenicity endpoints were geometric mean titre (GMT) ratios (GMRs) of RSV-A neutralising antibodies (nAbs; in parts A and B), GMRs of haemagglutination inhibition (HAI) titres to each of the four influenza strains in SIIV4 (A/Victoria/2570/2019 [H1N1]pdm09-like virus [A/H1N1], A/Cambodia/e0826360/2020 [H3N2]-like virus [A/H3N2], B/Washington/02/2019-like virus [B/Victoria], and B/Phuket/3073/2013-like virus [B/Yamagata]; in part A), GMRs of nAbs against SARS-CoV-2 (ancestral [D614G] and omicron BA.1; part B), and differences in seroresponse rates for nAbs against RSV-A (parts A and B) and SARS-CoV-2 (ancestral [D614G] and omicron BA.1; part B). Non-inferiority was declared when the lower bound of the 95% CI for GMRs was greater than 0·667 and for seroresponse rate differences was greater than -10%. This trial is registered with ClinicalTrials.gov (NCT05330975) and is ongoing.

FINDINGS

Between April 1 and June 9, 2022, 1631 participants were randomly allocated in part A and 1623 received vaccinations on day 1 (685 [42%] received mRNA-1345 plus SIIV4, 249 [15%] mRNA-1345 plus placebo, and 689 [42%] SIIV4 plus placebo). Due to an interactive response technology error, the mRNA-1345 plus placebo group was smaller than planned (249 vs 420 participants). Of the 1623 participants in the safety set, 877 (54%) were female and 746 (46%) were male. Between July 27 and Sept 28, 2022, 1691 participants were randomly allocated in part B and 1681 received vaccinations on day 1 (564 [34%] received mRNA-1345 plus mRNA-1273.214, 558 [33%] mRNA-1345 plus placebo, and 559 [33%] mRNA-1273.214 plus placebo). Among the 1681 participants in the safety set, 924 (55%) were female and 757 (45%) were male. The reactogenicity profiles of the coadministered regimens were generally similar to the profiles when the vaccines were administered alone. As of the 6-month and 7-month follow-up times for parts A and B, respectively, no serious adverse events, adverse events of special interest, discontinuations due to adverse events, or fatal events considered related to study vaccination were reported. In part A, the GMR of nAbs against RSV-A in the mRNA-1345 plus SIIV4 group versus the mRNA-1345 alone group was 0·81 (95% CI 0·67 to 0·97), and the seroresponse rate difference in nAbs against RSV-A between the groups was -11·2% (95% CI -17·9 to -4·1). GMRs of anti-HAI titres in the mRNA-1345 plus SIIV4 versus SIIV4 alone groups were 0·89 (0·77 to 1·03) for A/H1N1, 0·97 (0·86 to 1·09) for A/H3N2, 0·93 (0·82 to 1·05) for B/Victoria, and 0·91 (0·81 to 1·02) for B/Yamagata. In part B, the GMR of nAbs against RSV-A in the mRNA-1345 plus mRNA-1273.214 versus the mRNA-1345 alone groups was 0·80 (95% CI 0·70 to 0·90), and the seroresponse rate difference was -4·4% (95% CI -9·9 to 1·0). Comparing the mRNA-1345 plus mRNA-1273.214 group with the mRNA-1273.214 alone group, the GMR of nAbs was 0·96 (0·87 to 1·06) for the ancestral (D614G) virus and 1·00 (0·89 to 1·14) for omicron BA.1; seroresponse rate differences were 0·2% (95% CI -6·0 to 6·3) for SARS-CoV-2 ancestral and -0·9% (-6·6 to 4·7) for omicron BA.1.

INTERPRETATION

Coadministered mRNA-1345 plus SIIV4 or mRNA-1273.214 vaccines had acceptable safety profiles and elicited mostly non-inferior immune responses compared to individual vaccines in adults aged 50 years or older; only the seroresponse rate difference in nAbs against RSV-A in part A did not meet the non-inferiority criterion. Overall, these data support coadministration of mRNA-1345 with these vaccines in this population; longer-term evaluation continues in this study.

FUNDING

Moderna.

Aging enhances pro-atrogenic gene expression and skeletal muscle loss following respiratory syncytial virus infection

Aging and many age-related health conditions are associated with skeletal muscle loss. Furthermore, older adults are more susceptible to severe respiratory infections, which can in turn lead to muscle wasting. The mechanisms by which respiratory viral infection can impact skeletal muscle in older adults are not well understood. We determined the effects of acute infection with respiratory syncytial virus (RSV) on the lung and skeletal muscle of aged mice. RSV infection caused more severe disease in aged mice with enhanced weight loss, reduced feeding, higher viral load, and greater airway inflammation. Aged but not young mice showed decreased leg muscle weight at the peak of illness and decreased size of leg muscle fibers. Aged mice increased muscle-specific expression of atrophy-promoting enzymes (Atrogin-1 and MuRF-1) and failed to increase the rate of muscle protein synthesis during RSV infection. In aged mice, the changes in Atrogin-1 and MuRF-1 gene expression in skeletal muscle correlated with IL-6 levels in the lungs. These findings indicate that RSV infection of aged mice provides a model for studying the diverse adverse systemic consequences of respiratory viral infections on health and wellbeing in older adults.

Viral community-acquired pneumonia: what's new since COVID-19 emerged?

INTRODUCTION

All over the world, viral pneumonia has a significant impact on morbidity and mortality, especially among vulnerable populations. The most common respiratory viruses causing pneumonia include influenza virus, respiratory syncytial virus, adenoviruses and rhinovirus. The COVID-19 pandemic has changed the landscape of viral pneumonia and has reshaped our understanding of the role of viruses in this disease. We are now more aware of the importance of early diagnosis, the impact of co-infections, the effects of viral variants, and the long-term consequences of post-viral pneumonia.

AREAS COVERED

We discuss the latest scientific evidence regarding epidemiology, diagnosis, treatment, and prevention of viral pneumonia. This review summarizes findings from a PubMed search on respiratory viruses in community-acquired pneumonia.

EXPERT OPINION

Our experience during the COVID-19 pandemic has changed our perspective on respiratory viruses and their role in viral pneumonia. Diagnostic advances have been made, co-infections have received greater recognition, immune responses to viral infections are better understood, and approaches to treating viral pneumonia have expanded. Despite this progress, however, research on the impact of respiratory viruses on pneumonia must continue to pursue the development of new antivirals and vaccines, and investigate the long-term sequelae, especially in cases of severe viral pneumonia.

DNA-Encoded Library Screen Identifies Novel Series of Respiratory Syncytial Virus Polymerase Inhibitors

Respiratory syncytial virus (RSV) remains a public health burden due to unmet therapeutic needs. We recently reported the discovery of a non-nucleoside inhibitor of the RSV polymerase and characterized its binding to a novel pocket within the capping domain of the polymerase. Here, we describe our strategy to diversify the chemical matter targeting this site by screening our DNA-encoded chemical libraries, leading to the discovery of a novel and potent series of molecules that inhibits RSV polymerase's biochemical activity, as well as its viral replication in cells. Structural analysis via cryo-EM revealed novel contacts made within the capping domain binding pocket. By leveraging these structural insights for preliminary SAR exploration, we generated analogues for which potency and metabolic stability were improved more than 60- and 40-fold, respectively, over the initial hit. This work provides a path forward for further advanced SAR exploration and development of therapeutics against RSV.

Sex differences in acute respiratory tract infections-multi-year analysis based on data from a large tertiary care medical center in Israel

Introduction

Acute respiratory tract infections impose a considerable burden on the health services. The development of improved prevention and treatment measures requires a better understanding of the mechanisms of infection. Since sex has been shown to be an important biological variable in the immune response to infections, we aimed to assess sex differences in the incidence rates of respiratory infections.

Materials and methods

We obtained data on cases hospitalized with diagnosed respiratory tract infections by sex and age group over a period of 11 years (2012-2022) from the Sheba Medical Center (SMC), the largest tertiary care medical center in Israel. Nasopharyngeal samples collected from the patients with symptoms of a respiratory tract infection were examined for adenovirus, influenza, rhinovirus, parainfluenza-3, human metapneumovirus (hMPV) and respiratory syncitial virus (RSV) in the Central Virology Laboratory and Viral RNA/DNA was extracted and tested using a real-time reverse transcription-PCR (rRT-PCR) assay. We calculated annual male to female incidence rate ratios (IRRs) which were combined over the period of the study using meta-analysis methodology.

Results

There was a male excess in infection rates for all viruses, particularly in the youngest age groups of <0 and 1-4 years. Our analyses revealed that the influenza incidence rates were 42 and 28% higher in males in infants and toddlers. The male dominance was similar for adenovirus with 33 and 38% in infancy and age group 1-4. For RSV, the male to female IRR was higher at ages <1 and 1-4 (22 and 21% respectively). Males were more likely to be positive for rhinovirus in infancy and toddlers, by 40 and 25%, respectively.

Conclusion

There is evidence of an excess incidence of respiratory diseases in males. The mechanism is unclear. Other than behavioral factors, there is a need to study the role of sex hormones and genetic factors.

High bacterial coinfection rates and associated mortality among hospitalized older adults with laboratory-confirmed respiratory syncytial virus infection

BACKGROUND

Emerging evidence highlights that respiratory syncytial virus (RSV) poses a significant risk to older adults. However, detailed clinical data on elderly patients hospitalized with RSV remains limited. This study investigates the clinical characteristics and outcomes of older adults (aged ≥50 years) hospitalized with RSV infection.

METHODS

This retrospective cohort study included hospitalized patients aged ≥50 years with respiratory symptoms and laboratory-confirmed RSV infection at China Medical University Hospital between January 1, 2011, and December 31, 2023. Data on demographic characteristics and clinical presentations were collected. RSV infection-related outcomes were analyzed across various subgroups.

RESULTS

This study included 36 patients, with the most prevalent comorbidities being diabetes mellitus (47.2 %), immunocompromised status (36.1 %), and chronic lung disease (30.6 %). Pneumonia was identified in 72.2 % of patients, while 41.7 % required invasive mechanical ventilation, and the hospital mortality rate was 33.3 %. Non-survivors had higher rates of comorbidities, particularly chronic lung disease (66.7 % vs. 12.5 %, p = 0.002), higher disease severity, elevated procalcitonin levels, and were more likely to develop septic shock and acute respiratory distress syndrome. A bacterial coinfection rate of 33.3 % was observed, with patients experiencing pneumonia or bacterial coinfection showing poorer outcomes. Moreover, patients with chronic lung disease exhibited significantly worse day-28 survival (log-rank p < 0.001).

CONCLUSIONS

The disease burden of RSV in older adults is amplified by comorbidities such as chronic lung disease, with pneumonia and bacterial coinfections further worsening outcomes. Our findings highlight the need for a more comprehensive understanding and effective preventive strategies to protect this vulnerable population.

Epidemiological and Clinical Characteristics of Adult RSV Infections: A Retrospective Analysis at University Hospital Center Zagreb (2022-2024)

Respiratory syncytial virus (RSV) is a significant cause of respiratory infections in adults, particularly among older adults and individuals with chronic diseases. While traditionally linked to pediatric populations, RSV's impact on adults, especially the elderly, is increasingly recognized but remains understudied in many regions. This retrospective study, conducted at the University Hospital Center Zagreb from October 2022 to April 2024, is the first to analyze RSV-positive adults in Croatia. Using RT-PCR testing, we evaluated clinical and epidemiological characteristics in both hospitalized and outpatient populations, focusing on those aged > 65 years. Among 2631 tested individuals, the RSV prevalence was 5.25%, with older adults experiencing the most severe outcomes, including pneumonia, COPD exacerbation, and intensive care admissions. Seasonal analysis confirmed a winter peak in RSV cases, while chronic conditions such as cardiovascular and respiratory diseases were strongly associated with higher complication rates. These findings demonstrate that older adults with comorbidities bear the greatest burden of RSV infection, highlighting the need for the early identification of high-risk patients. By providing detailed insights into RSV-related outcomes in this population, this study supports the development of targeted prevention and management strategies to reduce the burden of RSV in vulnerable groups.

Autophagy and Respiratory Viruses: Mechanisms, Viral Exploitation, and Therapeutic Insights

Respiratory viruses, such as influenza virus, rhinovirus, coronavirus, and respiratory syncytial virus (RSV), continue to impose a heavy global health burden. Despite existing vaccination programs, these infections remain leading causes of morbidity and mortality, especially among vulnerable populations like children, older adults, and immunocompromised individuals. However, the current therapeutic options for respiratory viral infections are often limited to supportive care, underscoring the need for novel treatment strategies. Autophagy, particularly macroautophagy, has emerged as a fundamental cellular process in the host response to respiratory viral infections. This process not only supports cellular homeostasis by degrading damaged organelles and pathogens but also enables xenophagy, which selectively targets viral particles for degradation and enhances cellular defense. However, viruses have evolved mechanisms to manipulate the autophagy pathways, using them to evade immune detection and promote viral replication. This review examines the dual role of autophagy in viral manipulation and host defense, focusing on the complex interplay between respiratory viruses and autophagy-related pathways. By elucidating these mechanisms, we aim to highlight the therapeutic potential of targeting autophagy to enhance antiviral responses, offering promising directions for the development of effective treatments against respiratory viral infections.

Exploring case definitions and the natural history of respiratory syncytial virus in adult outpatients: First-season results of the RESPIRA-50 study

BACKGROUND

Data on the natural history of the community-acquired RSV in adult outpatients are limited. It is also unclear whether the existing influenza surveillance platforms based on influenza-like illness (ILI) case definitions are efficient for RSV. The two-season RESPIRA-50 study was established in 2023 to identify an optimal RSV case definition and to explore the natural history of RSV. Here, the first-season results are reported.

METHODS

The study was conducted in Genoa (Italy) during the 2023/2024 RSV season. Twenty-four general practitioners were randomized 1:1 to enroll adults aged ≥ 50 years seeking care for acute respiratory infection (ARI) or ILI, respectively. Both syndromes were defined according to the European criteria. All subjects were tested by real-time polymerase chain reaction (RT-PCR) for RSV and other pathogens. RSV-positive adults were followed for up to 30 days.

RESULTS

Of 517 subjects included, 7.0 % [95 % confidence interval (CI): 4.9-9.5 %)] tested positive for RSV. RSV prevalence in the ARI group (8.0 %; 95 % CI: 5.0-12.1 %) was higher than in the ILI group (6.0 %; 95 % CI: 3.5-9.5 %) with an odds ratio of 1.36 (95 % CI: 0.69-2.70). Conversely, positivity for influenza (10.4 % vs 12.4 %) and SARS-CoV-2 (12.4 % vs 16.9 %) were lower in the ARI group and the corresponding ORs were 0.82 (95 % CI: 0.48-1.42) and 0.70 (95 % CI: 0.43-1.15), respectively. The mean duration of an RSV episode was 18.8 ± 8.0 days and two thirds of individuals were prescribed antibiotics. A total of 33.3 % (95 % CI: 18.6-51.0 %) of RSV-positive individuals developed complications, of which bronchitis (13.9 %) and pneumonia (8.3 %) were the most frequent.

CONCLUSIONS

Compared with ARI, ILI-based surveillance may underestimate the burden of RSV in community-dwelling adults aged ≥ 50 years. A high proportion of RSV-positive adult outpatients develops complications, which lead to substantial resource consumption.

Perceived benefits, information, vaccination history, and conspiracy beliefs as significant determinants of RSV vaccine acceptance among Arab seniors

Background

Respiratory syncytial virus (RSV) poses a significant respiratory health risk to senior citizens, contributing substantially to hospitalizations and mortality. With the recent approval of three RSV vaccines for the elderly, it is critical to understand the factors that can shape the RSV vaccination attitudes to inform public health strategies that can enhance uptake among this vulnerable population.

Objectives

This study aimed to investigate the potential factors that could influence the attitudes toward RSV vaccination among senior citizens in Arab countries.

Design

A multinational cross-sectional study, adhering to STROBE guidelines, was conducted using a survey instrument previously validated through exploratory factor analysis to assess attitudes toward the newly approved RSV vaccine.

Methods

A self-administered online survey was distributed conveniently among senior citizens mainly across five Arab countries. The survey collected data on demographics, vaccination history, and key constructs related to RSV vaccine attitude, including "Fear," "Information," "Accessibility," "Benefits," and "Conspiracy."

Results

A total of 483 participants were included in the study, with the majority from five Arab countries: Jordan (n = 239, 49.5%), Kuwait (n = 74, 15.3%), Egypt (n = 68, 14.1%), Saudi Arabia (n = 51, 10.6%), and the UAE (n = 23, 4.8%), alongside participants from other Arab nations (n = 28, 5.8%). Among the respondents, 51.1% (n = 247) expressed acceptance of the RSV vaccine, 22.4% (n = 108) were hesitant, and 26.5% (n = 128) exhibited refusal. Multivariate analysis identified perceived benefits (β = 0.484, p < 0.001), information needs (β = 0.229, p < 0.001), and previous vaccination history (β = 0.087, p = 0.016) as significant positive predictors of vaccine acceptance. Conversely, stronger conspiracy beliefs (β = -0.083, p = 0.035) were associated with vaccine resistance. Fear and accessibility were not significant predictors of vaccine attitudes.

Conclusion

The findings showed that perceived benefits, access to reliable information, previous vaccination history, and conspiracy beliefs are essential to promote RSV vaccine acceptance among Arab seniors. These factors are recommended to improve RSV vaccine uptake in this vulnerable population.

Vaccination in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is often exacerbated by various viruses and bacteria, leading to acute episodes of worsening respiratory symptoms, which contribute significantly to the morbidity and mortality associated with COPD. Consequently, vaccination against these pathogens is recommended by numerous guidelines to safeguard COPD patients from adverse health outcomes. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommendation advocates for vaccination against influenza, Streptococcus pneumoniae, respiratory syncytial virus (RSV), severe acute respiratory syndrome coronavirus (SARS-CoV2), pertussis, and varicella zoster. This review article will examine the current vaccination strategies recommended for adult COPD patients and will discuss the clinical benefits associated with these vaccines.

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.

Meeting summary: Global vaccine and immunization research forum, 2023

At the 2023 Global Vaccine and Immunization Research Forum (GVIRF), researchers from around the world gathered in the Republic of Korea to discuss advances and opportunities in vaccines and immunization. Many stakeholders are applying the lessons of Covid-19 to future emergencies, by advancing early-stage development of prototype vaccines to accelerate response to the next emerging infectious disease, and by building regional vaccine research, development, and manufacturing capacity to speed equitable access to vaccines in the next emergency. Recent vaccine licensures include: respiratory syncytial virus vaccines, both for the elderly and to protect infants through maternal immunization; a new dengue virus vaccine; and licensure of Covid-19 vaccines previously marketed under emergency use authorizations. Malaria vaccine implementation is expanding and a second malaria vaccine has been recommended by the World Health Organization. In a setback for human immunodeficiency virus vaccine development, the only remaining Phase 3 trial has been discontinued. In immunization, greater clarity is emerging on the challenges of achieving access and equity, along with strategies to address those challenges. A better understanding of behavioral and social determinants of vaccine uptake and a validated toolkit for measuring and modifying the drivers of vaccination is informing program design and service delivery, contributing to improved uptake. Implementation research, which has been essential for human papillomavirus and malaria vaccine delivery, will be critical for delivering the new respiratory syncytial virus vaccines and for many other vaccines currently in development. The growing diversity of vaccines and complexity of immunization programs are leading to greater interest in simplified regimens, combination vaccines, and other innovations to facilitate delivery. Collaboration emerged as the unifying theme of GVIRF 2023, underscoring that the combined efforts of many contributors have enabled progress thus far, and going forward will continue to be essential to ensure equitable access to vaccines for all.

Knowledge and Attitudes Regarding Respiratory Syncytial Virus (RSV) Prevention: A Systematic Review

Background: New strategies for respiratory syncytial virus (RSV) prevention are available and are in development, but their acceptance is crucial to their effectiveness. Objectives: This systematic review aims to summarize current quantitative and qualitative evidence regarding knowledge and attitudes relating to RSV prevention. Methods: Six databases (PubMed, Scopus, APA PsycArticles; APA PsycInfo; CINAHL Complete; Psychology and Behavioral Sciences Collection) and two preprint repositories (medRxiv and Preprints) were searched up until 23 December 2024 (PROSPERO: CRD42024602351). Results: Sixty-one articles were included, focusing on vaccination for the elderly and adults at risk (n = 10) or pregnant people (n = 24, of which 8 also examined preferences for maternal vs. infant immunization) and infant immunization (n = 27, of which 16 focused on palivizumab, with 6 focusing on adherence to its monthly administration). Eighteen articles assessed attitudes in healthcare professionals. Overall, findings showed limited knowledge and awareness of RSV but generally positive attitudes towards prevention strategies and moderate to high intentions and uptake rates. Protection against the disease and perceived severity promoted acceptance, whereas concerns about side effects hindered it. Maternal vaccination was more acceptable than infant immunization. Conclusions: Attitudes towards RSV prevention options were generally favorable. Should more options become available, preferences may depend on which options are available, their characteristics, and how they are framed and presented. These insights highlight the importance of education on RSV grounded in decision-making literature, while recognizing the likely favorable reception of preventive measures across target age-populations.

Estimating the cost-effectiveness of maternal respiratory syncytial virus (RSV) vaccination in Australia: A dynamic and economic modelling analysis

BACKGROUND

Respiratory syncytial virus (RSV) is a major cause of respiratory illness, with younger infants at greatest risk of hospitalisation. With the recent approval of a maternal RSV vaccine in Australia, it is timely to evaluate its potential costs and health benefits in Australia.

METHODS

We applied an integrated dynamic and economic evaluation model to estimate specific outcomes of RSV disease and the cost-effectiveness of a year-round maternal RSV vaccination program in Australia. Cost-effectiveness was estimated using the incremental cost-effectiveness ratio (ICER) per quality-adjusted life year (QALY) gained.

RESULTS

From a healthcare system perspective, the maternal vaccination program was estimated to be cost-effective at a vaccine price less than approximately 120 Australian dollars ($AU), assuming a willingness-to-pay (WTP) threshold of $AU 50,000/QALY gained. Most of the estimated cost-savings were from preventing RSV hospitalisations in infants aged <6 months. However, while 82% of the cost-savings were from preventing RSV hospitalisations in infants aged <6 months, only about 25% of the QALY gains were in this age group. The majority of the other QALY gains came via herd effects from prevention of death in older adults and to a lesser extent, prevention of nonmedically-attended illness in older teens and adults. When predicted cost-savings and QALY gains in those ≥6 months of age were excluded, the vaccine price required to meet the assumed WTP threshold fell to $AU 63.

CONCLUSIONS

A maternal RSV vaccination program in Australia could provide value for money by reducing hospitalisations and associated costs among infants aged <6 months, depending on the vaccine price. We have provided evidence that herd effects beyond the target population may be an important consideration in assessing cost-effectiveness of maternal RSV vaccination.

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.

The global burden of human metapneumovirus-associated acute respiratory infections in older adults: a systematic review and meta-analysis

BACKGROUND

The human metapneumovirus (hMPV)-associated disease burden in older adults remains under-researched. We aimed to systematically estimate the global burden of hMPV-associated disease in older adults.

METHODS

We searched MEDLINE, Embase, Global Health, CINAHL, Web of Science, and Global Index Medicus in February, 2023, November, 2023, and October, 2024; and CNKI, Wanfang, and CQVip, in April, 2024, and October, 2024. We included studies conducted over at least 12 consecutive months, reporting on adults aged 60 years or older, and with laboratory-confirmed hMPV infections. Critical appraisal of included studies was conducted using the Joanna Briggs Institute critical appraisal tools. To estimate the hMPV pooled proportions positive in acute respiratory infections (ARIs), random effects meta-analyses were conducted. Using Monte Carlo simulation, we estimated the hMPV-associated hospitalisations globally and separately in high-income countries, low-income and middle-income countries, and the USA in individuals aged 65 years or older in 2019, as most studies reported on this age group. The hMPV-associated ARI incidence in countries other than the USA and in outpatient or community settings in the USA was summarised narratively due to scarcity of data. The review protocol was registered on PROSPERO (CRD42023422325).

FINDINGS

46 studies conducted between 2005 and 2023, and reporting on hMPV proportion positive estimates (n=36, with 29 866 laboratory tests), hospitalisation rates in the USA (n=4), and hMPV incidence (n=6) were included. We estimated 473 000 (95% CI 396 000-777 000) hMPV-associated hospitalisations globally, of which 185 000 (105 000-340 000) were in high-income countries (n=6 studies), and 288 000 (193 000-436 000) in low-income and middle-income countries (n=10 studies) in people aged 65 years or older in 2019. In the USA, the pooled hMPV-associated hospitalisation rate was 231 (95% CI 41-421) per 100 000 people in adults aged 65 years or older, representing approximately 122 000 (41 000-398 000) hospital admissions in this population in 2019.

INTERPRETATION

hMPV-associated ARIs contribute to a substantial disease and hospitalisation burden in older adults. However, more large-scale surveillance studies and greater investment in research and diagnostic methods are required to develop reliable estimates.

FUNDING

Icosavax, a member of the AstraZeneca group.

Recommendation for the use of respiratory syncytial virus vaccines

Respiratory syncytial virus (RSV) is the most common pathogen for young children hospitalized with bronchiolitis and pneumonia. Most infections occur below 1 year of age. RSV is also a significant viral pathogen for adults with respiratory tract infection. Vaccines targeting the pre-fusion protein of RSV, including recombinant and mRNA vaccines, are now available. A committee of experts from related fields was convened by the Taiwan Immunization Vision and Strategy to develop recommendations for RSV vaccination in the elderly and pregnant women. The recommendation is not intended as a sole source of guidance in the prevention of RSV infection in children. The provisions listed in this recommendation are comprehensive suggestions made by experts in Taiwan based on existing medical evidence. This recommendation should be subject to modification in light of additional medical research findings in the future, and these provisions should not be cited as a basis for dispute resolution.

Vaccination against Respiratory Infections in the Immunosenescent Older Adult Population: Challenges and Opportunities

Respiratory infections are associated with a huge burden of disease every year and disproportionately affect older adults, namely those aged 65 years and older. Older adults are at increased risk of infections compared with their younger counterparts, and once infected, have a higher risk of experiencing severe disease course, complications, and long-term sequelae. Therefore, vaccination is clearly a key strategy to prevent infection and its attendant negative consequences. We review here the burden of common respiratory diseases in older adults, namely influenza, pneumococcal disease, and respiratory syncytial virus. We then review some of the challenges facing immunization of older adults, namely immunosenescence, inflammaging, and low vaccine uptake. Next, potential opportunities for overcoming these challenges are reviewed, including the use of higher antigen doses and/or adjuvants in vaccine formulations for older adults, and the potential of multiomics analyses to improve development, performance, and implementation of vaccines.

Understanding the local-level variations in seasonality of human respiratory syncytial virus infection: a systematic analysis

BACKGROUND

While previous reports characterised global and regional variations in RSV seasonality, less is known about local variations in RSV seasonal characteristics. This study aimed to understand the local-level variations in RSV seasonality and to explore the role of geographical, meteorological, and socio-demographic factors in explaining these variations.

METHODS

We conducted a systematic literature review to identify published studies reporting data on local-level RSV season onset, offset, or duration for at least two local sites. In addition, we included three datasets of RSV activity from Japan, Spain, and Scotland with available site-specific data. RSV season onset, offset, and duration were defined using the annual cumulative proportion method. We estimated between-site variations within a region using the earliest onset, the earliest offset, and the shortest duration of RSV season of that region as the references and synthesised the variations across regions by a multi-level mixed-effects meta-analysis. Using the three datasets from Japan, Spain and Scotland, we applied linear regression models with clustered standard errors to explore the association of geographical, meteorological, and socio-demographic factors with the season onset and offset, respectively.

RESULTS

We included 7 published studies identified from the systematic literature search. With the additional 3 datasets, these data sources covered 888,447 RSV-positive cases from 101 local study sites during 1995 to 2020. Local-level variations in RSV season within a region were estimated to be 6 weeks (41 days, 95% CI: 25-57) for season onset, 5 weeks (32 days, 13-50) for season offset, and 6 weeks (40 days, 20-59) for season duration, with substantial differences across years. Multiple factors, such as temperature, relative humidity, wind speed, annual household income, population size, latitude, and longitude, could jointly explain 66% to 84% and 35% to 49% of the variations in season onset and offset, respectively, although their individual effects varied by individual regions.

CONCLUSIONS

Local-level variations in RSV season onset could be as much as 6 weeks, which could be influenced by meteorological, geographical, and socio-demographic factors. The reported variations in this study could have important implications for local-level healthcare resources planning and immunisation strategy.

TRIAL REGISTRATION

PROSPERO CRD42023482432.

An mRNA-Based Respiratory Syncytial Virus Vaccine Elicits Strong Neutralizing Antibody Responses and Protects Rodents Without Vaccine-Associated Enhanced Respiratory Disease

BACKGROUND

Respiratory syncytial virus (RSV) causes the most common type of severe lower respiratory tract infection worldwide, and the fusion (F) protein is a target for neutralizing antibodies and vaccine development. This study aimed to investigate the immunogenicity and efficacy of an mRNA-based RSV vaccine with an F protein sequence.

METHODS

We designed an mRNA construct encoding a modified RSV F protein, which was further developed into an LNP-encapsulated mRNA vaccine (LVRNA007). LVRNA007 was administered to mice and cotton rats, followed by immunogenicity analysis and viral challenge studies. Protection of rodents from the viral infection was evaluated based on the presence of the virus in the lung and pathological examination of respiratory tissues.

RESULTS

LVRNA007 induced robust humoral and cellular immune responses in both mice and cotton rats, with neutralization antibody levels in the immunized animals maintained at high levels for over one year. Vaccination of LVRNA007 also protected the rodents from RSV challenge, judged by the much decreased virus titer and the pathological score in the lung tissue. In addition, no vaccine-enhanced disease (VED) phenomenon was observed with LVRNA007 vaccination.

CONCLUSIONS

Based on the preclinical immunogenicity and efficacy data, LVRNA007 could be a potential promising vaccine for prophylaxis of RSV infection.

Interplay between respiratory viruses and cilia in the airways

The airway epithelium is the first point of contact for inhaled pathogens. The role of epithelial cells in clearance, infection and colonisation of bacteria is established. The interactions of respiratory viruses and cilia is less understood, but viruses are known to target ciliated epithelial cells for entry, replication and dissemination. Furthermore, some respiratory viruses impair and/or enhance ciliary activity. This review examines what is known about the interactions between cilia and viral infection and how respiratory viruses effect cilia function with subsequent consequences for human health. We discuss the models which can be used to investigate the relationship between respiratory viruses and the host airway.

Immunogenicity and safety of Ad26.RSV.preF/RSV preF protein vaccine at predicted intermediate- and end-of-shelf-life as an evaluation of potency throughout shelf life

This study assessed three Ad26.RSV.preF/RSV preF protein combinations, combining different Ad26.RSV.preF doses and naturally aged preF protein, representing the expected critical vaccine quality attributes close to release, around intermediate shelf-life (ISL) and near-presumed end-of-shelf-life (EoSL), as a way to evaluate the vaccine immunogenicity and safety throughout its shelf-life. A single dose of Ad26.RSV.preF/RSV preF protein vaccine was administered to adults 60-75 years of age. Solicited adverse events (AEs), unsolicited AEs, and serious AEs (SAEs) were assessed for 7-day, 28-day, and 6-month periods after vaccination, respectively. RSV preF-binding antibody concentrations and RSV neutralizing titers were measured 14 days post-vaccination as primary and secondary endpoints, respectively; binding antibodies were also measured 6 months post-vaccination. The RSV preF-binding antibody responses induced by Ad26.RSV.preF/RSV preF protein vaccine lots representing the critical quality attributes around ISL and near presumed EoSL were noninferior to the responses induced by the vaccine lot representing the critical quality attributes near release. The RSV preF-binding and RSV neutralizing antibody levels measured 14 days post-vaccination were similar across the 3 groups. RSV preF-binding antibody concentrations were also similar 6 months post-vaccination. Solicited AEs were mostly mild to moderate in intensity, and a decreased reactogenicity was observed from the Release group to the ISL and EoSL group. None of the reported SAEs were considered related to study vaccination. The study provided evidence of sustained immunogenicity and safety over the intended shelf-life of the Ad26.RSV.pref/RSV preF protein vaccine. The three vaccine lots had acceptable safety profiles.

Immunogenicity, safety and reactogenicity of Ad26.RSV.preF/RSV preF protein vaccine in adults aged 60 to 75 years: A comparison of phase 2b and phase 3 clinical trial material

The Ad26.RSV.preF/RSV preF protein vaccine has previously demonstrated efficacyin protecting older adults against respiratory syncytial virus (RSV)-related lower respiratory tract disease in a phase 2b study. This study compared the immunogenicity of vaccine clinical trial material (CTM) representative of phase 2b clinical studies with CTM used in phase 3 clinical studies. A total of 248 adults aged 60-75 years, randomized in a 1:1 ratio, received one dose of either phase 3 CTM or phase 2b CTM. Solicited adverse events (AEs), unsolicited AEs, and serious AEs (SAEs) were assessed for 7-d, 28-d, and 6-month periods post-vaccination, respectively. RSV preF-ELISA antibody titers and RSV neutralizing titers were measured before and 14 d after vaccination. The phase 3 CTM-induced preF-ELISA response at Day 15, in terms of geometric mean titer, was shown to be non-inferior to that induced by phase 2b CTM. The RSV neutralizing antibody titers were also similar in the two groups at Day 15. The safety profile in terms of solicited AEs, unsolicited AEs, or SAEs was in general similar between the phase 3 CTM and phase 2b CTM groups, and solicited AEs were mostly mild to moderate in intensity. No related SAEs were reported, and no safety concerns were identified.

Landscape of respiratory syncytial virus

ABSTRACT

Respiratory syncytial virus (RSV) is an enveloped, negative-sense, single-stranded RNA virus of the Orthopneumovirus  genus of the Pneumoviridae family in the order Mononegavirales. RSV can cause acute upper and lower respiratory tract infections, sometimes with extrapulmonary complications. The disease burden of RSV infection is enormous, mainly affecting infants and older adults aged 75 years or above. Currently, treatment options for RSV are largely supportive. Prevention strategies remain a critical focus, with efforts centered on vaccine development and the use of prophylactic monoclonal antibodies. To date, three RSV vaccines have been approved for active immunization among individuals aged 60 years and above. For children who are not eligible for these vaccines, passive immunization is recommended. A newly approved prophylactic monoclonal antibody, Nirsevimab, which offers enhanced neutralizing activity and an extended half-life, provides exceptional protection for high-risk infants and young children. This review provides a comprehensive and detailed exploration of RSV's virology, immunology, pathogenesis, epidemiology, clinical manifestations, treatment options, and prevention strategies.

mRNA Vaccines Against COVID-19 as Trailblazers for Other Human Infectious Diseases

mRNA vaccines represent a milestone in the history of vaccinology, because they are safe, very effective, quick and cost-effective to produce, easy to adapt should the antigen vary, and able to induce humoral and cellular immunity.

METHODS

To date, only two COVID-19 mRNA and one RSV vaccines have been approved. However, several mRNA vaccines are currently under development for the prevention of human viral (influenza, human immunodeficiency virus [HIV], Epstein-Barr virus, cytomegalovirus, Zika, respiratory syncytial virus, metapneumovirus/parainfluenza 3, Chikungunya, Nipah, rabies, varicella zoster virus, and herpes simplex virus 1 and 2), bacterial (tuberculosis), and parasitic (malaria) diseases.

RESULTS

RNA viruses, such as severe acute respiratory syndrome coronavirus (SARS-CoV)-2, HIV, and influenza, are characterized by high variability, thus creating the need to rapidly adapt the vaccines to the circulating viral strain, a task that mRNA vaccines can easily accomplish; however, the speed of variability may be higher than the time needed for a vaccine to be adapted. mRNA vaccines, using lipid nanoparticles as the delivery system, may act as adjuvants, thus powerfully stimulating innate as well as adaptive immunity, both humoral, which is rapidly waning, and cell-mediated, which is highly persistent. Safety profiles were satisfactory, considering that only a slight increase in prognostically favorable anaphylactic reactions in young females and myopericarditis in young males has been observed.

CONCLUSIONS

The COVID-19 pandemic determined a shift in the use of RNA: after having been used in medicine as micro-RNAs and tumor vaccines, the new era of anti-infectious mRNA vaccines has begun, which is currently in great development, to either improve already available, but unsatisfactory, vaccines or develop protective vaccines against infectious agents for which no preventative tools have been realized yet.

Incidence of RSV in Adults: A Comprehensive Review of Observational Studies and Critical Gaps in Information

BACKGROUND

We conducted a global comprehensive literature review of observational studies reporting respiratory syncytial virus (RSV) incidence in adults and determined current evidence gaps.

METHODS

PubMed and Embase were searched for English-language publications (2000-2022) and congress abstracts (2019-2021) reporting RSV incidence rates/cumulative incidence. Cross-sectional studies, case series, and other designs estimating only RSV frequency were excluded. The search included all geographic areas; data were extracted by age group and underlying condition where available.

RESULTS

In total, 528 potentially relevant records were identified, of which 37 primary studies were relevant to this review. Most evidence was from high-income regions. Approximately two-thirds of the studies reported RSV incidence in the hospital setting. Fifteen studies included or focused exclusively on RSV incidence in adult populations with underlying conditions. Studies varied in their measurement and presentation of incidence. RSV incidence estimates were highly variable within and between geographic regions. Overall, RSV incidence tended to increase with age and was highest in adults with underlying conditions.

CONCLUSIONS

Estimates of RSV incidence are highly variable across populations and geographies. Further population-based studies with well-defined, consistent case definitions and surveillance strategies are needed for accurate and comparable estimates of RSV incidence, particularly in the geographic regions identified by the gap analysis.

Adult vaccination in India: A rapid review of current status & implementation challenges

Background & objectives The expanded programme on immunization launched in India in 1978, with its focus on preventing six diseases in children (tetanus, diphtheria, pertussis, poliomyelitis, typhoid, and childhood tuberculosis), was widened in its scope in 1985-86. This new avtaar, the Universal Immunization Programme (UIP), incorporated measles vaccine for children and rubella and adult diphtheria vaccines for pregnant women. We conducted this rapid review on adult immunization relevant for India, as recent COVID-19 experience revealed how newly emergent or re-emergent pathogens could have their onslaughts on the elderly and adults with comorbidities. Methods Three different bibliographic databases, namely PubMed, Scopus and Ovid were searched electronically to access the articles published in peer-reviewed journals. Relevant consensus guidelines by in-country professional groups were also collated. We conducted deduplication and screening of the outputs of these searches (1242 bibliographical records). Finally, 250 articles were found eligible for inclusion. As trials on the reduction of morbidities, mortalities and hospitalizations in adults due to proposed vaccines under Indian consensus guidelines were not available, no meta-analysis was conducted. Results Evidence from articles finally included in this synthesis were grouped under (i) preventing viral and bacterial infections in adults; (ii) adult vaccination and awareness tools; (iii) vaccine hesitancy/acceptance; and (iv) adult vaccination guidelines. In-country research revealed the need for introducing the Human Papilloma Virus (HPV) vaccine in adolescence or early-adulthood to prevent ano-genital cancers in elderly and later life. Importantly HPV prevalence among cervical cancer patients varied between 88 to 98 per cent in Andhra Pradesh, Odisha and Delhi. The importance of conducting regular surveillance of pneumococcal diseases and influenza, as well as tweaking the vaccines accordingly, was revealed in other articles. A poor uptake of influenza vaccine (≤2%) in adults (≥45 yr) was documented. The uptake of hepatitis B vaccine in Health Care Workers (HCWs) in Delhi and Mumbai was of concern and ranged from 55 to 64 per cent. The vulnerability of HCWs to rubella was investigated in a paediatric ophthalmic hospital in Madurai: a tenth of the selected HCWs were rubella seronegative and mounted good protective immunity following RA 27/3 vaccine administration. An outbreak of measles in college students in Pune emphasized the phenomenon of waning immunity. Similarly, a study in the infectious disease hospital in Kolkata and in-patients in Delhi revealed a lack of protective immunity against diphtheria and tetanus in adults. The researchers estimated the economic benefits of providing a typhoid vaccine to a household to be US$ 23 in a middle-income neighbourhood and US$ 14 in slum settings. The authors highlighted the importance of preventive strategies, finding that the cost of severe typhoid fever was US$ 119.1 in 18 centres across India. Both qualitative and quantitative investigations explored vaccine hesitancy, which was studied more during the COVID-19 pandemic than earlier. Interpretation & conclusions Vaccination programmes in India would require (i) increasing awareness around vaccine-preventable diseases among adults and HCWs; (ii) actively engaging health care systems and community-based organizations; and (iii) developing and producing affordable, safe, and country-appropriate vaccines. Effective communication strategies and tools will be the key to the success of such interventions.

Modelling the epidemiological impact of maternal respiratory syncytial virus (RSV) vaccination in Australia

BACKGROUND

Respiratory syncytial virus (RSV) is a leading cause of respiratory illness among infants. A maternal RSV vaccine that protects young infants has recently been approved for registration in Australia. We estimated the population benefits of a future year-round maternal RSV vaccination program in terms of prevented RSV infections and hospitalisations in Australia.

METHODS

We described RSV transmission using an age-structured compartmental model calibrated to Australian aggregated monthly RSV-coded hospitalisations in children aged <5 years. We accounted for mother and infant interactions in the model to capture herd effects more realistically. Using the model, we estimated the annual age-specific RSV infections and hospitalisations prevented for a range of assumptions for vaccine efficacy, coverage, and durability to estimate the future impact of year-round maternal RSV vaccination on infants and the wider population.

RESULTS

Assuming base case vaccine efficacy, 6 months duration of protection and 70% coverage, RSV hospitalisations were predicted to fall by 60% (from 3.0 to 1.2 per 100 persons) in infants aged <3 months and 40% (from 1.9 to 1.1 per 100 persons) in 3-5-month-olds. These benefits were primarily due to direct protection to infants of vaccinated mothers. This vaccine program was predicted to reduce the population-level RSV infection by about 4%. Coverage and duration assumptions were influential, with higher coverage leading to larger declines in infants <6 months, and increased duration of protection leading to additional declines in infection and hospitalisation risk in older infants aged 6-8 months.

CONCLUSIONS

With vaccine uptake similar to that achieved for other maternal vaccines in Australia, a year-round RSV maternal vaccination program is predicted to approximately halve the number of RSV hospitalisations in infants younger than 6 months. There was a small herd effect predicted in the base case but potential for larger benefits if vaccine coverage or the duration of protection exceeds base case assumptions.

A multivalent RSV vaccine based on the modified vaccinia Ankara vector shows moderate protection against disease caused by RSV in older adults in a phase 3 clinical study

Respiratory syncytial virus (RSV) causes a significant disease burden in older adults. The live recombinant vaccine based on a nonreplicating modified vaccinia Ankara (MVA-BN) poxvirus, MVA-BN-RSV, encoding for multiple proteins of RSV subtypes A and B, was assessed for efficacy against respiratory disease caused by RSV. Adults aged ≥60 years, with or without underlying chronic conditions, were enrolled and randomized in a 1:1 ratio to receive a single dose of vaccine or placebo and were followed for disease caused by RSV infection during the 2022-2023 season. The 2 primary endpoints were RSV-associated lower respiratory tract disease (LRTD) with ≥3 and ≥ 2 symptoms; acute respiratory disease (ARD) was a key secondary endpoint. The humoral RSV-specific immune response was assessed at baseline and 14 days post-vaccination. Safety was evaluated by collection of solicited adverse events (AEs) and unsolicited AEs for 7 and 28 days post-vaccination respectively, and SAEs for the entire study period. In total, 18,348 participants were included in the final efficacy and safety analyses. Vaccine efficacy was 42.9 % (95 % CI: -16.1; 71.9) against RSV-associated LRTD with ≥3 symptoms, 59.0 % (95 % CI: 34.7; 74.3) against LRTD with ≥2 symptoms, and 48.8 % (95 % CI: 25.8; 64.7) against ARD. The primary objective was not met for LRTD with ≥3 symptoms since the lower bound of the 95 % CI was below 20 %, the prespecified success criterion. The vaccine-elicited immune response showed mean fold-increases of 1.7 for RSV A and B neutralizing antibodies and 2.9 and 4.3 for RSV-specific IgG and IgA, respectively. The vaccine displayed mild to moderate reactogenicity, and no safety concerns were identified. MVA-BN-RSV induced suboptimal protection against RSV-associated LRTD, likely due to suboptimal neutralizing antibody response. The vaccine had an acceptable safety profile and confirmed immunogenicity, overall showing promise for MVA-BN-vectored constructs targeting other diseases. Trial Registration:Clinicaltrials.gov Identifier NCT05238025 (Registered February 14, 2022).

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.

Vaccine and therapeutic agents against the respiratory syncytial virus: resolved and unresolved issue

Respiratory syncytial virus (RSV) is a predominant pathogen responsible for respiratory tract infections among infants, the elderly, and immunocompromised individuals. In recent years, significant progress has been made in innovative vaccines and therapeutic agents targeting RSV. Nevertheless, numerous challenges and bottlenecks persist in the prevention and treatment of RSV infections. This review will provide an overview of the resolved and unresolved issues surrounding the development of vaccines and therapeutic agents against RSV. As of September 2024, three RSV vaccines against acute lower respiratory infections (ALRI) have been approved globally. Additionally, there have been notable progress in the realm of passive immunoprophylactic antibodies, with the monoclonal antibody nirsevimab receiving regulatory approval for the prevention of RSV infections in infants. Furthermore, a variety of RSV therapeutic agents are currently under clinical investigation, with the potential to yield breakthrough advancements in the foreseeable future. This review delineates the advancements and challenges faced in vaccines and therapeutic agents targeting RSV. It aims to provide insights that will guide the development of effective preventive and control measures for RSV.

Advancements and challenges in the management of pneumonia in elderly patients with COPD

INTRODUCTION

Chronic Obstructive Pulmonary Disease (COPD) significantly predisposes the elderly to pneumonia, presenting a complex interplay of pulmonary dysfunction and infection risk.

AREAS COVERED

This article reviews the substantial epidemiologic impact, elucidates the interlinked pathophysiology of COPD and pneumonia, and examines the microbial landscape shaping infection in these patients. It also evaluates management protocols and the multifaceted clinical challenges encountered during treatment.

EXPERT OPINION

Delving into the latest research, we underscore the criticality of preventive measures such as vaccination and present an integrated approach to managing Community-Acquired Pneumonia (CAP) in the COPD demographic. The review also proposes strategic directions for future investigations aimed at enhancing patient outcomes through a deeper understanding of the COPD-pneumonia nexus.

Loop-mediated isothermal amplification (LAMP) for detection of atypical enterovirus D68 strain VR-1197

A method that has rapidly evolved for detection of viral pathogens are loop-mediated isothermal amplification (LAMP) assays. The available LAMP assays usually target the most common viral strains, including enteroviruses, but for the atypical enterovirus D68 strain VR-1197 this method has not yet been developed. Enterovirus D68 are known for severe respiratory distress in children, and atypical strains are less likely to be detected by traditional methods. This study targets the atypical EVD68 strain VR-1197 and have developed a rapid detection method saving time when differentiating enterovirus strains. This study present method development and review the sensitivity and specificity compared to traditional RT-qPCR, and wet lab cross reactivity with other airway pathogens. The EVD68 VR-1197 assay can be a rapid POC (Point of care) test for atypical EVD68 VR-1197 and have the potential as reliable detection method with minimal technological requirements.

Impact of COVID-19 control measures on respiratory syncytial virus and hand-foot-and-mouth disease transmission in Hong Kong and South Korea

The public health and social measures (PHSMs) for mitigation/control of COVID-19 pandemic influenced the transmission dynamics of many other infectious diseases, including respiratory syncytial virus (RSV) infection, and hand, foot and mouth disease (HFMD) and their disease-burden. This study aimed to infer the transmission dynamics of these respiratory viruses and assess the impact of COVID-19 PHSMs on their community activity. We developed a compartmental framework to infer the transmission dynamics of RSV and HFMD in Hong Kong and South Korea from January 2014 to May 2024. We assessed the impact of PHSMs by comparing the change in virus transmissibility, reproduction number and population susceptibility before, during, and after the COVID-19 pandemic period. A significant reduction in RSV and HFMD activity was observed starting in January 2020, with a resurgence since late 2021. Transmissibility of both diseases decreased by 46 % - 95 % during the lull, while population susceptibility was estimated to increase by maximum of 19 %. On relaxation of the PHSMs, the transmissibility were recovered up to 70 % in Hong Kong and nearly 100 % in South Korea in 2023 with significant epidemics for these viruses. Strict implementation of COVID-19 PHSMs led to low RSV and HFMD activity, but the absence of community infection resulted in reductions in population immunity, and slightly larger epidemics when these diseases re-emerged following the COVID-19 pandemic.

Biology of human respiratory syncytial virus: Current perspectives in immune response and mechanisms against the virus

Human respiratory syncytial virus (hRSV) remains a leading cause of morbidity and mortality in infants, young children, and older adults. hRSV infection's limited treatment and vaccine options significantly increase bronchiolitis' morbidity rates. The severity and outcome of viral infection hinge on the innate immune response. Developing vaccines and identifying therapeutic interventions suitable for young children, older adults, and pregnant women relies on comprehending the molecular mechanisms of viral PAMP recognition, genetic factors of the inflammatory response, and antiviral defense. This review covers fundamental elements of hRSV biology, diagnosis, pathogenesis, and the immune response, highlighting prospective options for vaccine development.