Open research questions in Respiratory viral infections research

What the literature leaves open

• The study identifies a gap in the understanding of the impact of the SARS-CoV-2 pandemic on healthcare service utilization for respiratory infections in children. Prior studies have documented a decrease in demand for medical care during the pandemic, but the study aims to analyze the temporal trends in consultations for respiratory infections among children under 15 in Anoia from 2017 to 2024.

  Temporal Trends in the Use of Healthcare Services for Respiratory Infections in the Paediatric Population of Anoia (2017–2024): Primary and Hospital Care · 2026 · DOI

• Imperfect PCR detection, - Antibody ceiling effect, - Study conducted in a high-burden setting, - Limited to a specific population in The Gambia

  Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting · 2026 · DOI

• Investigating the mechanisms underlying incomplete protection following infection, - Studying the kinetics and durability of antibody responses to different RSV antigens, - Examining age-dependent differences in immune responses

  Mucosal IgA to pre-fusion F protein predicts protection from RSV infection in a high burden setting · 2026 · DOI

• International guidelines do not support the routine use of nebulized epinephrine for acute viral bronchiolitis. Evidence for the use of nebulized epinephrine in bronchiolitis remains inconclusive.

  Nebulized Epinephrine Versus Placebo in Infants with Moderate-to-Severe Bronchiolitis: A Randomized Controlled Trial · 2026 · DOI

• The study notes the challenge of detecting RSV cases during the COVID-19 pandemic, particularly during periods of stringent public health interventions. The researchers highlight the difficulty in characterizing the molecular characteristics of RSV due to the limited availability of sequence data. The study cites the challenge of understanding the impact of the COVID-19 pandemic on RSV epidemiology, particularly in the context of changing public health interventions.

  Epidemiology of human RSV in Taiwan, 2018–2024 · 2026 · DOI

• There is a need to understand the impact of the COVID-19 pandemic on RSV circulation. The study highlights the gap in knowledge regarding the epidemiology of RSV in Taiwan, particularly in the context of the COVID-19 pandemic. The researchers note that there is a lack of data on the molecular characteristics of RSV in Taiwan.

  Epidemiology of human RSV in Taiwan, 2018–2024 · 2026 · DOI

• Increasing coverage of pneumococcal conjugate vaccines and rotavirus vaccines in resource-limited G20 settings, - Strengthening pathogen surveillance, - Improving access to timely diagnosis and treatment for severe infections

  Burden of 46 key pathogens among children in G20 countries, 2023: A systematic analysis and regional comparison · 2026 · DOI

• The study faces challenges in estimating the true burden of RSV disease due to non-specific presentation and limited testing. The study must account for the impact of the COVID-19 pandemic on RSV hospitalization trends and seasonality. The study must also consider the variability in healthcare resource utilization and comorbidities among adults aged 60 years or more with RSV infection.

  Burden of respiratory syncytial virus (RSV) hospitalizations among adults aged 60 years or more in Brazil: A retrospective surveillance database analysis (2013–2024) · 2026 · DOI

• the study was a retrospective analysis of existing data, - the data may not be comprehensive due to limited testing and non-specific presentation of RSV, - the study did not include primary collection of individual human subject data

  Burden of respiratory syncytial virus (RSV) hospitalizations among adults aged 60 years or more in Brazil: A retrospective surveillance database analysis (2013–2024) · 2026 · DOI

• further studies are needed to understand the long-term impact of the pandemic on healthcare utilisation, - research on the effectiveness of measures to mitigate the transmission of respiratory pathogens is needed, - studies on the impact of the pandemic on specific age groups and conditions are required

  Temporal Trends in the Use of Healthcare Services for Respiratory Infections in the Paediatric Population of Anoia (2017–2024): Primary and Hospital Care · 2026 · DOI

• Further studies are needed to determine the effectiveness of nebulized racemic epinephrine in infants with moderate-to-severe bronchiolitis, - Research on the long-term effects of nebulized racemic epinephrine in this population is required, - Studies with larger sample sizes and prospectively registered protocols are necessary

  Nebulized Epinephrine Versus Placebo in Infants with Moderate-to-Severe Bronchiolitis: A Randomized Controlled Trial · 2026 · DOI

• Conclusions Vaccination rates in patients with bronchiectasis increase with disease severity but remain insufficient, particularly in those with mild disease.

  Influenza and pneumococcal vaccination rates across FACED severity categories in bronchiectasis · 2026 · DOI

• Vaccination coverage across different levels of bronchiectasis severity has not been well characterized.

  Influenza and pneumococcal vaccination rates across FACED severity categories in bronchiectasis · 2026 · DOI

• However, its impact on respiratory syncytial virus (RSV) epidemiology in sub-Saharan Africa is understudied.

  Delayed seasonality but consistent age burden: RSV epidemiology pre-, during and post-COVID-19 pandemic on the Kenyan Coast (2008-2026) · 2026 · DOI

• Abstract Background The factors that determine how quickly immunosenescence occurs in individuals are not yet fully understood.

  Acute viral respiratory infections are not associated with an increased IMMune Age indeX (IMMAX) four weeks after infection: a prospective observational cohort study · 2026 · DOI

• However, studies regarding trends in the prevalence of ARI and its associated factors over a wide period are scarce.

  Trends in acute respiratory infection and associated factors among under-5 children in Ethiopia · 2026 · DOI

• BACKGROUND: Post-COVID-19 respiratory pathogen dynamics remain incompletely characterized, particularly in the Arabian Peninsula.

  Respiratory pathogen epidemiology in the post-pandemic era: a multicenter retrospective study from Saudi Arabia · 2026 · DOI

• This review underscores the necessity of mental health support following respiratory infections in children, highlights the need for further research on the biological and psychosocial pathways linking respiratory illnesses to psychological outcomes, and emphasizes the value of multidisciplinary treatment strategies for children with such comorbidities.

  Exploring long-term psychological effects of bronchiolitis and influenza in school-aged children · 2025 · DOI

• However, the risk factors for recurrent wheezing or asthma after infant bronchiolitis remain controversial.

  Risk factors for recurrent wheezing after infant bronchiolitis: a 6-year single-centre follow up study in China · 2025 · DOI

• While several risk factors for severe RSV illness are known, the role of host genetic susceptibility remains underexplored, particularly in East Asian populations.

  Genetic susceptibility associated with hospitalization due to respiratory syncytial virus in a group of Taiwanese children: a preliminary study · 2025 · DOI

• Background Acute bronchiolitis is a leading cause of hospitalization in young children worldwide, and literature reports conflicting data regarding the role of coinfections.

  Clinical relevance of bacterial and/or viral coinfection in acute bronchiolitis in an Italian neonatal unit during the 2021–2023 seasons · 2025 · DOI

• However, its clinical severity and epidemiological characteristics remain poorly understood.

  Human metapneumovirus in children with acute lower respiratory infections: effects on clinical and disease severity · 2025 · DOI

• This finding provides important evidence for the early precise classification of pediatric CAP and the rational use of antibiotics, but its clinical value still needs to be validated through larger-scale multicenter studies.

  C-reactive protein and serum amyloid A protein as complementary biomarkers in differentiating viral and bacterial community-acquired pneumonia in children · 2025 · DOI

• Therefore, a better understanding of the pediatric antiviral immune response to pneumovirus infections is warranted.

  Differential immune responses of pediatric and adult primary epithelial cells to human respiratory pneumovirus infection 3262 · 2025 · DOI

• However, the causal pathways of bacterial-viral co-infections, particularly the mechanisms by which commensal microbiota could modulate SP-RSV-associated LRTI outcomes remain to be elucidated.

  Lower respiratory tract co-infection of Streptococcus pneumoniae and respiratory syncytial virus shapes microbial landscape and clinical outcomes in children · 2025 · DOI

Most-cited papers in Respiratory viral infections research

• Identification of a Novel Coronavirus in Patients with Severe Acute Respiratory Syndrome · New England Journal of Medicine · 2003 · 3,708 citations
• Mortality Associated With Influenza and Respiratory Syncytial Virus in the United States · JAMA · 2003 · 2,998 citations
• Global burden of acute lower respiratory infections due to respiratory syncytial virus in young children: a systematic review and meta-analysis · The Lancet · 2010 · 2,405 citations
• Coronavirus as a possible cause of severe acute respiratory syndrome · The Lancet · 2003 · 2,346 citations
• Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in young children in 2015: a systematic review and modelling study · The Lancet · 2017 · 2,190 citations
• Respiratory Syncytial Virus Infection in Elderly and High-Risk Adults · New England Journal of Medicine · 2005 · 1,987 citations
• The Burden of Respiratory Syncytial Virus Infection in Young Children · New England Journal of Medicine · 2009 · 1,946 citations
• Palivizumab, a Humanized Respiratory Syncytial Virus Monoclonal Antibody, Reduces Hospitalization From Respiratory Syncytial Virus Infection in High-risk Infants · PEDIATRICS · 1998 · 1,807 citations
• Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in children younger than 5 years in 2019: a systematic analysis · The Lancet · 2022 · 1,737 citations
• A Major Outbreak of Severe Acute Respiratory Syndrome in Hong Kong · New England Journal of Medicine · 2003 · 1,704 citations

Most recent work

• Respiratory Virus Activity — United States, July 1, 2024–June 30, 2025 · MMWR Morbidity and Mortality Weekly Report · 2026
• Risk of Cardiorespiratory Events Following Respiratory Syncytial Virus–Related Hospitalization · JAMA Network Open · 2026
• Interim Safety of RSVpreF Vaccination During Pregnancy · JAMA · 2026
• Six-year epidemiological dynamics of human respiratory syncytial virus infections in children in central China (2019-2024): pandemic suppression, 2023 resurgence, and immune debt effect · Frontiers in Cellular and Infection Microbiology · 2026
• Respiratory viral infections prime accelerated lung cancer growth · Cell · 2026
• Maternal RSV Vaccination, Infant Nirsevimab, or Both: Interim Analysis of a Randomized Trial · PEDIATRICS · 2026
• Cost-Effectiveness of Nirsevimab and Maternal RSVpreF Immunization Strategies in Low-Risk Infants · PEDIATRICS · 2026
• Epidemiological and immunological insights into respiratory infections in post-COVID-19 · Frontiers in Cellular and Infection Microbiology · 2026
• Comprehensive insights into pathogen distribution, clinical features, and outcomes in pediatric severe pneumonia · Frontiers in Cellular and Infection Microbiology · 2026
• Estimating the burden of RSV- and influenza-associated ED visits, hospitalizations, ICU admissions, and deaths across age and socioeconomic groups in New York State, 2005–2019 · BMC Infectious Diseases · 2026

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