Global Respiratory Syncytial Virus-Related Infant Community Deaths

Evaluation of the potential impact and cost-effectiveness of respiratory syncytial virus (RSV) prevention strategies for infants in Argentina

BACKGROUND

New interventions are available for the prevention of respiratory syncytial virus (RSV) disease in young infants. We aimed to assess the potential impact and cost-effectiveness of using a long-acting monoclonal antibody (RSV mAb) or maternal RSV vaccine in the Argentine context.

METHODS

We used a static proportionate outcomes model to calculate the costs and consequences of using RSV mAb or maternal RSV vaccine over a ten-year period (2025-2034) in Argentina, assuming both year-round and seasonal administration. We compared each intervention to no pharmaceutical RSV intervention. The primary outcome was the discounted cost per disability-adjusted life year (DALY) averted from a societal perspective. We assumed willingness-to-pay of US$ 12,285 per DALY averted (0.9 times the national gross domestic product per capita). We used population study data on costs and disease burden and the efficacy of clinical trials of both interventions as inputs. We ran deterministic and probabilistic uncertainty analyses.

FINDINGS

Either strategy (RSV mAb or maternal RSV vaccine) could prevent >25% of RSV deaths aged <5 years and ∼30% aged <6 months (the age group where most intervention impact occurs). With a dose price of $US 50, both products have a 100% probability of being cost-effective compared to no intervention (US$ 5283 [95%CI $5203-$5363] and US$ 5522 [95%CI $5427 - $5617] per DALY averted for year-round use of RSV mAb and maternal RSV vaccine, respectively). Similar health impact could be achieved by a six-month seasonal strategy, which could improve cost-effectiveness by around 45% (assuming the dose price is unchanged).

INTERPRETATION

Either RSV mAb or maternal RSV vaccine are worth consideration in Argentina when priced at ≤US$ 50 per dose. A seasonal strategy could improve cost-effectiveness.

Respiratory syncytial virus infection among children younger than 2 years admitted to a paediatric intensive care unit with extended severe acute respiratory infection in ten Gavi-eligible countries: the RSV GOLD-ICU Network study

BACKGROUND

Patient-level data on life-threatening respiratory syncytial virus (RSV) infection in children in low-income and lower-middle-income countries (LMICs) are scarce, and this scarcity might limit demand for RSV interventions in LMICs who rely on support from Gavi, the Vaccine Alliance. We aimed to describe the characteristics of RSV-positive children younger than 2 years who were admitted to paediatric intensive care units (PICUs) with extended severe acute respiratory infection (eSARI) in Gavi-eligible countries.

METHODS

The RSV GOLD-ICU Network study is a 2-year prospective, multicountry, observational study of children younger than 2 years admitted to a PICU with eSARI. The study was conducted at 12 referral hospitals in Bolivia, Cameroon, The Gambia, Ghana, Haiti, Mozambique, Nepal, Nigeria, Sudan, and Tanzania. For comparison with a high-income country, patients were also included from two referral hospitals in the Netherlands. Children were eligible for inclusion if they were aged between 4 days and 2 years, admitted to a PICU, and met the WHO eSARI definition. RSV infection was confirmed within 72 h of PICU admission via a molecular point-of-care test at LMIC study sites and via a PCR test at the Dutch study sites. Clinical data were extracted from admission charts of patients; underlying conditions that were identified at admission were classified as comorbidities. Socioeconomic and demographic data were collected via a written, structured, parental questionnaire.

FINDINGS

Between April 28, 2021, and Sept 30, 2023, we included 2118 children who were admitted to a PICU with eSARI in the ten participating countries. 614 (29·0%; range 23·0-38·2) of 2118 children tested positive for RSV and 608 were included in descriptive analyses as six medical files were lost at one study site and data could not be retrieved. Among all 608 children infected with RSV, 379 (62%) were male and 229 (38%) were female. Median age at testing was 3·0 months (IQR 1·3-7·7). 30 (5%) of 608 children died from RSV infection. RSV fatality occurred at seven of ten participating LMIC study sites and was highest in Tanzania (seven [27%] of 26 children). Median age at testing of children who died with RSV infection was 1·8 months (IQR 1·1-4·2).

INTERPRETATION

To our knowledge, this is the first prospective, multicountry study reporting data from children admitted to a PICU with life-threatening RSV infection in Gavi-eligible countries. As there is no access to intensive care for most children in LMICs, RSV prevention is urgently needed.

FUNDING

Bill & Melinda Gates Foundation.

TRANSLATIONS

For the Arabic, Portuguese, Hausa and Nepali translations of the abstract see Supplementary Materials section.

Nirsevimab and Acute Bronchiolitis Episodes in Pediatric Emergency Departments

BACKGROUND AND OBJECTIVES

In the 2023-2024 respiratory syncytial virus (RSV) season, Spain became one of the first countries to introduce universal RSV prophylaxis, during which all infants born at this time were eligible to receive nirsevimab. Locally, most Spanish regions also immunized infants younger than age 6 months at the start of the season (extended catch-up). The aim of this study was to assess how RSV prophylaxis affected the number of infants presenting to pediatric emergency departments with acute respiratory infections.

METHODS

A retrospective study was conducted in 15 Spanish pediatric emergency departments from 9 different regions between the 2018 and 2024 epidemic seasons (November-January). We compared the seasons occurring in 2018-2023 and the 2023-2024 season regarding the number of episodes of lower respiratory tract infection and acute bronchiolitis, acute bronchiolitis-related hospital admissions, and PICU admissions.

RESULTS

A comparison with the average rates for the previous epidemic seasons revealed a 57.7% decrease in episodes of lower respiratory tract infection in 2023-2024 (95% CI, 56.5-58.8; P < .001; range among hospitals, 4.8-82.8), a 59.2% decrease in episodes of acute bronchiolitis (95% CI, 57.9-60.4; P < .001; range, 6.9-84.1), a 63.1% reduction in acute bronchiolitis-related hospital admissions (95% CI, 60.9-65.2; P < .001; range, 31.4-86.8), and a 63.1% reduction in PICU admissions (95% CI, 58.1-67.9; P < .001; range, 18.2-81.8). Hospitals in regions applying extended catch-up showed better results.

CONCLUSIONS

Nirsevimab can protect a broad infant population against RSV infection with high effectiveness. Approaches including extended catch-up are the most effective, although cost- effectiveness must be considered.

Characteristics of inpatient and outpatient respiratory syncytial virus mortality in Gavi-eligible countries

The current understanding of the RSV-related mortality age distribution in low- and lower-middle-income countries (LMICs) relies on a limited number of disease incidence studies reporting wide age bands, and lacking specificity to Gavi-eligible countries. Understanding the age distribution of RSV-related deaths is crucial for the implementation of RSV interventions in LMICs that rely on support from Gavi. This study aims to provide the age profile of RSV mortality specifically in Gavi-eligible countries. Utilizing data from the RSV GOLD project, an ongoing global online mortality registry focusing on children under the age of 5 with laboratory-confirmed RSV infection, we employed two models (Complete Data Model and Prospective Data Model) to estimate the age profiles. To mitigate biases related to age group representation, we applied post-stratification weighting in our analysis. We included 423 pediatric deaths, including 145 from the community, under 2 years of age from 15 Gavi-eligible countries. Both models identified a peak age at 1 month and found that the majority of RSV-related mortality cases (59-77 %) from Gavi-eligible countries occur before 6 months of life. However, the models exhibited disparities in other age-related metrics. We present fitted age-at-time-of-death probability distributions to aid impact and cost-effectiveness studies. We expect that implementing infant RSV immunization strategies, such as maternal vaccination or infant immunoprophylaxis, will have high impact on RSV-related mortality in Gavi-eligible countries. The divergent results from the two models underscore the importance of carefully considering potential biases in retrospective and surveillance data when interpreting the age profile of RSV mortality cases in future research.

The Prognosis in Children With Pneumonia of Respiratory Syncytial Virus Co-detection With Airway Dominant Flora

BACKGROUND

Airway bacterial microbiota influences the prognosis in children with respiratory syncytial virus infection. The study aimed to investigate the effect of the airway-dominant bacterial microbiota on disease severity in children with pneumonia of respiratory syncytial virus infection.

METHODS

A retrospective study was conducted in the Children's Hospital of Chongqing Medical University, which involved a cohort of patients with respiratory syncytial virus (RSV)-infected pneumonia from January 2012 to December 2021. Patients were assigned to a normal flora group or to a dominant flora group (with the top 5 individual bacteria) based on the nasopharyngeal aspirates culture and matched using propensity-score matching. Univariate analysis and multivariate analysis were performed to estimate the risk factors of poor prognosis in dominant flora.

RESULTS

Five thousand five hundred and twelve patients in the normal flora and 4556 in the dominant flora were included ( Escherichia coli 514, Streptococcus pneumoniae 1516, Staphylococcus aureus 506, Moraxella catarrhalis 509 and Haemophilus influenzae 1516, respectively). The dominant flora had more patients developing severe pneumonia, needing mechanical ventilation/tracheal intubation (up to 15.8% in the S. aureus ) and admission to the intensive care unit (up to 4.5% in the E. coli ) than in the normal flora (28.5% vs. 25.9%; P = 0.001; 9.8% vs. 5.4%; P < 0.001; 2.0% vs. 1.2%; P <0.001). And the hospitalization was longer in the dominant flora than in the normal flora [8 (6-9) vs. 8 (7-9) days; P < 0.001], the E. coli and S. aureus had the longest hospitalization [8 (7-10) days]. Several factors were associated with critical illness in Dominant flora according to multivariate analysis ( P < 0.001), including age (OR: 0.965; CI: 0.954-0.976; P < 0.001), anhelation (OR: 0.530; CI: 0.446-0.631; P < 0.001), disorders of consciousness (OR: 0.055; CI: 0.016-0.185; P < 0.001) as well as assisted respiration (OR: 0.115; CI: 0.097-0.138; P < 0.001), C-reactive protein >10 mg/L (OR: 0.686; CI: 0.560-0.839; P < 0.001), SpO 2 <90% (OR: 0.366; CI: 0.214-0.628; P < 0.001), pulmonary consolidation (OR: 0.511; CI: 0.364-0.717; P < 0.001) and pulmonary atelectasis (OR: 0.362; CI: 0.236-0.555; P < 0.001).

CONCLUSIONS

The airway-dominant bacterial microbiota influenced disease severity and comorbidities in children with RSV-infected pneumonia. Clinicians should pay attention to the nasopharyngeal aspirate culture, especially after detecting S. aureus and E. coli in RSV-infected children with pneumonia, closely observe the disease progression and take timely measures to avoid adverse outcomes.

Severe respiratory syncytial virus infection in children: burden, management, and emerging therapies

The global burden of respiratory syncytial virus (RSV) lower respiratory tract infection (LRTI) in young children is high. The RSV prevention strategies approved in 2023 will be essential to lowering the global disease burden. In this Series paper, we describe clinical presentation, burden of disease, hospital management, emerging therapies, and targeted prevention focusing on developments and groundbreaking publications for RSV. We conducted a systematic search for literature published in the past 15 years and used a non-systematic approach to analyse the results, prioritising important papers and the most recent reviews per subtopic. Annually, 33 million episodes of RSV LRTI occur in children younger than 5 years, resulting in 3·6 million hospitalisations and 118 200 deaths. RSV LRTI is a clinical diagnosis but a clinical case definition and universal clinical tool to predict severe disease are non-existent. The advent of molecular point-of-care testing allows rapid and accurate confirmation of RSV infection and could reduce antibiotic use. There is no evidence-based treatment of RSV, only supportive care. Despite widespread use, evidence for high-flow nasal cannula (HFNC) therapy is insufficient and increased paediatric intensive care admissions and intubation indicate the need to remove HFNC therapy from standard care. RSV is now a vaccine-preventable disease in young children with a market-approved long-acting monoclonal antibody and a maternal vaccine targeting the RSV prefusion protein. To have a high impact on life-threatening RSV infection, infants at high risk, especially in low-income and middle-income countries, should be prioritised as an interim strategy towards universal immunisation. The implementation of RSV preventive strategies will clarify the full burden of RSV infection. Vaccine probe studies can address existing knowledge gaps including the effect of RSV prevention on transmission dynamics, antibiotic misuse, the respiratory microbiome composition, and long-term sequalae.

The cost of care for children hospitalized with respiratory syncytial virus (RSV) associated lower respiratory infection in Kenya

BACKGROUND

Respiratory syncytial virus (RSV) is one of the main causes of hospitalization for lower respiratory tract infection in children under five years of age globally. Maternal vaccines and monoclonal antibodies for RSV prevention among infants are approved for use in high income countries. However, data are limited on the economic burden of RSV disease from low- and middle-income countries (LMIC) to inform decision making on prioritization and introduction of such interventions. This study aimed to estimate household and health system costs associated with childhood RSV in Kenya.

METHODS

A structured questionnaire was administered to caregivers of children aged < 5 years admitted to referral hospitals in Kilifi (coastal Kenya) and Siaya (western Kenya) with symptoms of acute lower respiratory tract infection (LRTI) during the 2019-2021 RSV seasons. These children had been enrolled in ongoing in-patient surveillance for respiratory viruses. Household expenditures on direct and indirect medical costs were collected 10 days prior to, during, and two weeks post hospitalization. Aggregated health system costs were acquired from the hospital administration and were included to calculate the cost per episode of hospitalized RSV illness.

RESULTS

We enrolled a total of 241 and 184 participants from Kilifi and Siaya hospitals, respectively. Out of these, 79 (32.9%) in Kilifi and 21(11.4%) in Siaya, tested positive for RSV infection. The total (health system and household) mean costs per episode of severe RSV illness was USD 329 (95% confidence interval (95% CI): 251-408 ) in Kilifi and USD 527 (95% CI: 405- 649) in Siaya. Household costs were USD 67 (95% CI: 54-80) and USD 172 (95% CI: 131- 214) in Kilifi and Siaya, respectively. Mean direct medical costs to the household during hospitalization were USD 11 (95% CI: 10-12) and USD 67 (95% CI: 51-83) among Kilifi and Siaya participants, respectively. Observed costs were lower in Kilifi due to differences in healthcare administration.

CONCLUSIONS

RSV-associated disease among young children leads to a substantial economic burden to both families and the health system in Kenya. This burden may differ between Counties in Kenya and similar multi-site studies are advised to support cost-effectiveness analyses.

Prevalence of Bacterial Codetection and Outcomes for Infants Intubated for Respiratory Infections

OBJECTIVES

To determine the prevalence of respiratory bacterial codetection in children younger than 2 years intubated for acute lower respiratory tract infection (LRTI), primarily viral bronchiolitis, and identify the association of codetection with mechanical ventilation duration.

DESIGN

Prospective observational study evaluating the prevalence of bacterial codetection (moderate/heavy growth of pathogenic bacterial plus moderate/many polymorphonuclear neutrophils) and the impact of codetection on invasive mechanical ventilation (IMV) duration.

SETTING

PICUs in 12 high and low/middle-income countries.

PATIENTS

Children younger than 2 years old requiring intubation and ICU admission for LRTI and who had a lower respiratory tract culture obtained at the time of intubation between December 1, 2019, and November 30, 2020.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of the 472 analyzed patients (median age 4.5 mo), 55% had a positive respiratory culture and 29% ( n = 138) had codetection. 90% received early antibiotics starting at a median of 0.36 hours after respiratory culture. Median (interquartile range) IMV duration was 151 hours (88, 226), and there were 28 deaths (5.3%). Codetection was more common with younger age, a positive respiratory syncytial virus test, and an admission diagnosis of bronchiolitis; it was less common with an admission diagnosis of pneumonia, with admission to a low-/middle-income site, and in those receiving vasopressors. When adjusted for confounders, codetection was not associated with longer IMV duration (adjusted relative risk 0.854 [95% CI 0.684-1.065]). We could not exclude the possibility that codetection might be associated with a 30-hour shorter IMV duration compared with no codetection, although the CI includes the null value.

CONCLUSIONS

Bacterial codetection was present in almost a third of children younger than 2 years requiring intubation and ICU admission for LRTI, but this was not associated with prolonged IMV. Further large studies are needed to evaluate if codetection is associated with shorter IMV duration.

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

BACKGROUND

Information is scarce regarding the economic burden of respiratory syncytial virus (RSV) disease in low-resource settings. This study aimed to estimate the cost per episode of hospital admissions due to RSV severe disease in Argentina.

METHODS

This is a prospective cohort study that collected information regarding 256 infants under 12 months of age with acute lower respiratory tract infection (ALRTI) due to RSV in two public hospitals of Buenos Aires between 2014 and 2016. Information on healthcare resource use was collected from the patient's report and its associated costs were estimated based on the financial database and account records of the hospitals. We estimated the total cost per hospitalization due to RSV using the health system perspective. The costs were estimated in US dollars as of December 2022 (1 US dollar = 170 Argentine pesos).

RESULTS

The mean costs per RSV hospitalization in infants was US$587.79 (95% confidence interval [CI] $535.24 - $640.33). The mean costs associated with pediatric intensive care unit (PICU) admission more than doubled from those at regular pediatric wards ($1,556.81 [95% CI $512.21 - $2,601.40] versus $556.53 [95% CI $514.59 - $598.48]).

CONCLUSIONS

This study shows the direct economic impact of acute severe RSV infection on the public health system in Argentina. The estimates obtained from this study could be used to inform cost-effectiveness analyses of new preventive RSV interventions being developed.

The global burden of lower respiratory infections attributable to respiratory syncytial virus in 204 countries and territories, 1990-2019: findings from the Global Burden of Disease Study 2019

AIMS

The purpose of this study is to investigate the global epidemiological characteristics of lower respiratory infections (LRI) burden attributable to respiratory syncytial virus (RSV) from 1990 to 2019.

MATERIALS AND METHODS

We used the recent Global Burden of Disease Study (GBD) 2019 to systematically evaluate the current burden and temporal trend of LRI burden attributable to RSV by global, age, sex, geographic location, and socio-economic status.

RESULTS

Globally, the disability-adjusted life years (DALYs) cases of LRI attributable to RSV dropped from an estimated 39,964,488 [95% uncertainty interval (UI): 16,825, 572 to 68,800,553] in 1990 to 14,956,514 (95%UI: 6,271,751 to 25,910,753) in 2019 and estimated death cases droped from 541,172 (95%UI:226,614 to 958,596) to 338,495 (95%UI:126,555 to 667,109) from1990 to 2019. Similarly, age-standardized DALYs rate of LRI attributable to RSV decreased from an estimated 646.2 (95%UI: 276.9 to 1121.5) in 1990 to 218.3 (95%UI:92.1 to 376.8) in 2019 and estimated age-standardized deaths rate decreased from 10.3 (95%UI:4.1 to 18.5) to 4.8 (95%UI:1.8 to 9.3) between 1990 and 2019. In 2019, the highest age-standardized DALYs and death rates of LRI attributable to RSV were seen in the lower SDI regions, children and old people. From 1990 to 2019, age-standardized DALYs and death rates of LRI attributable to RSV decreased with increasing SDI.

CONCLUSIONS

In this study, we found that the LRI burden attributable to RSV decreased significantly from 1990 to 2019. However, the lower SDI regions, children and old people urgently require cost-effective interventions to prevent and reduce the LRI burden attributable to RSV.

Human-virus protein-protein interactions maps assist in revealing the pathogenesis of viral infection

Many significant viral infections have been recorded in human history, which have caused enormous negative impacts worldwide. Human-virus protein-protein interactions (PPIs) mediate viral infection and immune processes in the host. The identification, quantification, localization, and construction of human-virus PPIs maps are critical prerequisites for understanding the biophysical basis of the viral invasion process and characterising the framework for all protein functions. With the technological revolution and the introduction of artificial intelligence, the human-virus PPIs maps have been expanded rapidly in the past decade and shed light on solving complicated biomedical problems. However, there is still a lack of prospective insight into the field. In this work, we comprehensively review and compare the effectiveness, potential, and limitations of diverse approaches for constructing large-scale PPIs maps in human-virus, including experimental methods based on biophysics and biochemistry, databases of human-virus PPIs, computational methods based on artificial intelligence, and tools for visualising PPIs maps. The work aims to provide a toolbox for researchers, hoping to better assist in deciphering the relationship between humans and viruses.

Maternal vaccination against RSV can substantially reduce childhood mortality in low-income and middle-income countries: A mathematical modeling study

Background

Respiratory syncytial virus (RSV) is a leading cause of childhood mortality in infants below 6 months of age. In low-income and middle-income countries (LMICs), the public health burden is substantial and resources are limited. It is critical to inform decision makers about effectiveness of new interventions.

Methods

We developed a mathematical model where individual RSV subtype A (RSV-A) and B (RSV-B) maternally derived neutralizing titers were predicted at time of birth after maternal vaccination with the RSV prefusion F protein-based vaccine. We estimated the subsequent duration of vaccine-induced immunity and compared this to the age at time of death distribution in the RSV GOLD Mortality Database to predict the potential impact of maternal vaccination on RSV-related childhood mortality. We used country-specific timing of antenatal care visits distributions and mortality estimates to make country-specific predictions for number of cases averted.

Findings

The model predicts that on average a neonate born at 40 weeks gestational age will be protected between 6 and 7 months from RSV-A and approximately 5 months from RSV-B related mortality. We estimated the potential impact of RSV-related mortality for in-hospital and out-of-hospital cases in LMICs and predicted that in 51 GAVI-eligible countries maternal vaccination could avert between 55% and 63% of the RSV-related in-hospital mortality cases below 6 months of age.

Interpretation

We show that maternal vaccination could substantially decrease RSV-A and RSV-B related in-hospital and out-of-hospital mortality in LMICs in the first 6 months of life.

Multilevel analysis identifying the factors associated with RSV detection in infants admitted for viral bronchiolitis in the era of the COVID-19 pandemic

OBJECTIVES

To identify factors independently associated with respiratory syncytial virus (RSV) detection in infants admitted for viral bronchiolitis during 3 consecutive years, before and during the COVID-19 pandemic, in Bogota, Colombia, a middle-income country with a subtropical highland climate.

METHODS

An analytical cross-sectional study was conducted before and during the COVID-19 pandemic, including patients with a diagnosis of viral bronchiolitis admitted to all the hospitals of the city between January 2019 and November 2021. We evaluated a set of a priori-selected predictor variables that included individual, healthcare system, meteorological, air pollutant, and COVID-19 variables. Since the variables analyzed are hierarchical in nature, multilevel modeling was used to identify factors independently associated with detection of RSV as the causative agent of viral bronchiolitis.

RESULTS

A total of 13,177 patients were included in the study. After controlling for potential confounders, it was found that age (odds ratio [OR] 0.86; 95% confidence interval [CI] 0.76-0.97), a third level of medical care institution (OR 3.05; 95% CI 1.61-5.76), temperature (OR 1.60; 95% CI 1.24-2.07), rainfall (OR 1.003, 95% CI 1.001, 1.005), NO2 (OR 0.97; 95% CI 0.95-0.99), CO (OR 0.99; 95% CI 0.99-0.99), and COVID-19 pandemic period (OR 0.84, 95% CI 0.71-0.99) were independently associated with RSV detection in our sample of patients.

CONCLUSIONS

The identified factors associated with RSV detection provide additional scientific evidence that may be useful in the development of specific interventions aimed at ameliorating or preventing the impact of RSV in Bogota and probably other similar low- to middle-income countries in high-risk infants.

The road to approved vaccines for respiratory syncytial virus

After decades of work, several interventions to prevent severe respiratory syncytial virus (RSV) disease in high-risk infant and older adult populations have finally been approved. There were many setbacks along the road to victory. In this review, I will discuss the impact of RSV on human health and how structure-based vaccine design set the stage for numerous RSV countermeasures to advance through late phase clinical evaluation. While there are still many RSV countermeasures in preclinical and early-stage clinical trials, this review will focus on products yielding long-awaited efficacy results. Finally, I will discuss some challenges and next steps needed to declare a global victory against RSV.

Respiratory Syncytial Virus Infection Among Hospitalized Infants in Four Middle-Income Countries

BACKGROUND

Understanding respiratory syncytial virus (RSV) global epidemiology is important to inform future prevention strategies.

METHODS

Hospitalized infants <1-year-old with acute illness were enrolled prospectively in Albania, Jordan, Nicaragua, and Philippines during respiratory seasons in 2015-2017. Medical chart review, parental interview, and post-discharge follow up were conducted. Respiratory specimens were tested using real-time RT-PCR for RSV. Infant characteristics associated with very severe illness (intensive care unit [ICU] admission or receipt of supplemental oxygen) were assessed using logistic regression to adjust for potential confounders (age, sex, study site, and preterm birth).

RESULTS

Of 3634 enrolled hospitalized infants, 1129 (31%) tested positive for RSV. The median age of RSV-positive infants was 2.7 (IQR: 1.4-6.1) months and 665 (59%) were male. Very severe illness in 583 (52%) RSV-positive infants was associated with younger age (aOR 4.1, 95% CI: 2.6-6.5 for 0-2 compared to 9-11-months; P < .01), low weight-for-age z-score (aOR 1.9, 95% CI: 1.2-2.8; P < .01), ICU care after birth (aOR 1.6, 95% CI: 1.0-2.5; P = .048), and cesarean delivery (aOR 1.4, 95% CI: 1.0-1.8; P = .03). RSV subgroups A and B co-circulated at all sites with alternating predominance by year; subgroup was not associated with severity (aOR 1.0, 95% CI: 0.8-1.4). Nine (0.8%) RSV-positive infants died during admission or within ≤30 days of discharge, of which 7 (78%) were <6-months-old.

CONCLUSIONS

RSV was associated with nearly a third of infant acute illness hospitalizations in four middle-income countries during the respiratory season, where, in addition to young age, factors including low weight-for-age might be important predictors of severity. RSV prevention strategies targeting young infants could substantially reduce RSV-associated hospitalizations in middle-income countries.

The age profile of respiratory syncytial virus burden in preschool children of low- and middle-income countries: A semi-parametric, meta-regression approach

BACKGROUND

Respiratory syncytial virus (RSV) infections are among the primary causes of death for children under 5 years of age worldwide. A notable challenge with many of the upcoming prophylactic interventions against RSV is their short duration of protection, making the age profile of key interest to the design of prevention strategies.

METHODS AND FINDINGS

We leverage the RSV data collected on cases, hospitalizations, and deaths in a systematic review in combination with flexible generalized additive mixed models (GAMMs) to characterize the age burden of RSV incidence, hospitalization, and hospital-based case fatality rate (hCFR). Due to the flexible nature of GAMMs, we estimate the peak, median, and mean incidence of infection to inform discussions on the ideal "window of protection" of prophylactic interventions. In a secondary analysis, we reestimate the burden of RSV in all low- and middle-income countries. The peak age of community-based incidence is 4.8 months, and the mean and median age of infection is 18.9 and 14.7 months, respectively. Estimating the age profile using the incidence coming from hospital-based studies yields a slightly younger age profile, in which the peak age of infection is 2.6 months and the mean and median age of infection are 15.8 and 11.6 months, respectively. More severe outcomes, such as hospitalization and in-hospital death have a younger age profile. Children under 6 months of age constitute 10% of the population under 5 years of age but bear 20% to 29% of cases, 28% to 39% of hospitalizations, and 38% to 50% of deaths. On an average year, we estimate 28.23 to 31.34 million cases of RSV, between 2.95 to 3.35 million hospitalizations, and 16,835 to 19,909 in-hospital deaths in low, lower- and upper middle-income countries. In addition, we estimate 17,254 to 23,875 deaths in the community, for a total of 34,114 to 46,485 deaths. Globally, evidence shows that community-based incidence may differ by World Bank Income Group, but not hospital-based incidence, probability of hospitalization, or the probability of in-hospital death (p ≤ 0.01, p = 1, p = 0.86, 0.63, respectively). Our study is limited mainly due to the sparsity of the data, especially for low-income countries (LICs). The lack of information for some populations makes detecting heterogeneity between income groups difficult, and differences in access to care may impact the reported burden.

CONCLUSIONS

We have demonstrated an approach to synthesize information on RSV outcomes in a statistically principled manner, and we estimate that the age profile of RSV burden depends on whether information on incidence is collected in hospitals or in the community. Our results suggest that the ideal prophylactic strategy may require multiple products to avert the risk among preschool children.

Immunization with a mucosal, post-fusion F/G protein-based polyanhydride nanovaccine protects neonatal calves against BRSV infection

Human respiratory syncytial virus (HRSV) is a leading cause of death in young children and there are no FDA approved vaccines. Bovine RSV (BRSV) is antigenically similar to HRSV, and the neonatal calf model is useful for evaluation of HRSV vaccines. Here, we determined the efficacy of a polyanhydride-based nanovaccine encapsulating the BRSV post-fusion F and G glycoproteins and CpG, delivered prime-boost via heterologous (intranasal/subcutaneous) or homologous (intranasal/intranasal) immunization in the calf model. We compared the performance of the nanovaccine regimens to a modified-live BRSV vaccine, and to non-vaccinated calves. Calves receiving nanovaccine via either prime-boost regimen exhibited clinical and virological protection compared to non-vaccinated calves. The heterologous nanovaccine regimen induced both virus-specific cellular immunity and mucosal IgA, and induced similar clinical, virological and pathological protection as the commercial modified-live vaccine. Principal component analysis identified BRSV-specific humoral and cellular responses as important correlates of protection. The BRSV-F/G CpG nanovaccine is a promising candidate vaccine to reduce RSV disease burden in humans and animals.

Respiratory Syncytial Virus (RSV) Disease and Prevention Products: Knowledge, Attitudes, and Preferences of Kenyan Healthcare Workers in Two Counties in 2021

Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infection (LRTI) among infants under 6 months of age. Yet, in Kenya, little is known about healthcare workers' (HCWs) knowledge, attitudes, and perceptions around RSV disease and the prevention products under development. Between September and October 2021, we conducted a mixed methods cross-sectional survey to assess HCWs' knowledge, attitudes, and perceptions of RSV disease and RSV vaccinations in two counties. We enrolled HCWs delivering services directly at maternal and child health (MCH) departments in selected health facilities (frontline HCWs) and health management officers (HMOs). Of the 106 respondents, 94 (88.7%) were frontline HCWs, while 12 were HMOs. Two of the HMOs were members of the Kenya National Immunization Technical Advisory Group (KENITAG). Of the 104 non-KENITAG HCWs, only 41 (39.4%) had heard about RSV disease, and 38/41 (92.7%) felt that pregnant women should be vaccinated against RSV. Most participants would recommend a single-dose vaccine schedule (n = 62, 58.5%) for maximal adherence and compliance (n = 38/62, 61.3%), single dose/device vaccines (n = 50/86, 58.1%) to prevent wastage and contamination, and maternal vaccination through antenatal care clinics (n = 53, 50%). We found the need for increased knowledge about RSV disease and prevention among Kenyan HCWs.

The Efficiency of p27 Cleavage during In Vitro Respiratory Syncytial Virus (RSV) Infection Is Cell Line and RSV Subtype Dependent

Respiratory syncytial virus (RSV) fusion protein (F) is highly conserved between subtypes A and B (RSV/A and RSV/B). To become fully active, F precursor undergoes enzymatic cleavage to yield F1 and F2 subunits and releases a 27-amino-acid peptide (p27). Virus-cell fusion occurs when RSV F undergoes a conformational change from pre-F to post-F. Previous data show that p27 is detected on RSV F, but questions remain regarding if and how p27 affects the conformation of mature RSV F. Monoclonal antibodies against p27, site Ø (pre-F specific), and site II were used to monitor RSV F conformation by enzyme-linked immunosorbent assay (ELISA) and imaging flow cytometry. Pre-F to post-F conformational change was induced by a temperature stress test. We found that p27 cleavage efficiency was lower on sucrose-purified RSV/A (spRSV/A) than on spRSV/B. In addition, cleavage of RSV F was cell line dependent: HEp-2 cells had higher retention of p27 than did A549 cells when infected with RSV. Higher levels of p27 were also found on RSV/A-infected cells than on RSV/B-infected cells. We observed that RSV/A F with higher p27 levels could better sustain the pre-F conformation during the temperature stress challenge in both spRSV- and RSV-infected cell lines. Our findings suggest that despite F sequence similarity, p27 of RSV subtypes was cleaved with different efficiencies, which were also dependent on the cell lines used for infection. Importantly, the presence of p27 was associated with greater stability of the pre-F conformation, supporting the possibility that RSV has more than one mechanism for fusion to the host cell. IMPORTANCE RSV fusion protein (F) plays an important role in entry and viral fusion to the host cell. The F undergoes proteolytic cleavages releasing a 27-amino-acid peptide (p27) to become fully functional. The role of p27 in viral entry and the function of the partially cleaved F containing p27 has been overlooked. p27 is thought to destabilize the F trimers, and thus, there is need for a fully cleaved F. In this study, we detected p27 on purified RSV virions and on the surface of virus-infected HEp-2 and A549 cells for circulating RSV strains of both subtypes. Higher levels of partially cleaved F containing p27 better sustained the pre-F conformation during the temperature stress challenge. Our findings highlight that the cleavage efficiency of p27 is different between RSV subtypes and among cell lines and that the presence of p27 contributes to the stability of the pre-F conformation.

Responding to Higher-Than-Expected Infant Mortality Rates from Respiratory Syncytial Virus (RSV): Improving Treatment and Reporting Strategies

Respiratory syncytial virus (RSV) has a major role in respiratory infections in young infants around the world. However, substantial progress has been made in recent years in the field of RSV. A wide variety of observational studies and clinical trials published in the past decade provide a thorough idea of the health and economic burden of RSV disease in the developing world. In this review, we discuss the impact of RSV burden of disease, major gaps in disease estimations, and challenges in generating new therapeutic options and an immune response against the virus, and briefly describe next generation technologies that are being evaluated.

Nosocomial RSV-related In-hospital Mortality in Children <5 Years: A Global Case Series

BACKGROUND

According to the World Health Organization, the global burden of nosocomial infections is poorly characterized as surveillance systems are lacking. Nosocomial infections occur at higher rates in low- and lower-middle-income countries (LMICs) than in high-income countries (HICs). Current global RSV burden estimates are largely based on community-acquired infection. We aimed to characterize children with nosocomial RSV-related mortality and to understand the potential impact of RSV immunization strategies.

MATERIALS

RSV GOLD is a global registry of children younger than 5 years who died with laboratory-confirmed RSV infection. We compared clinical and demographic characteristics of children with nosocomial and community-acquired RSV in-hospital mortality.

RESULTS

We included 231 nosocomial and 931 community-acquired RSV-related in-hospital from deaths from 65 countries. Age at death was similar for both groups (5.4 vs. 6 months). A higher proportion of nosocomial deaths had comorbidities (87% vs. 57%; P < 0.001) or was born preterm (46% vs. 24%; P < 0.001) than community-acquired deaths. The proportion of nosocomial deaths among all RSV deaths was lower in LMICs than in upper-middle-income countries (UMICs) and HICs (12% vs. 18% and 26%, respectively).

CONCLUSIONS

This is the first global case series of children dying with nosocomial RSV infection. Future infant-targeted immunization strategies could prevent the majority of nosocomial RSV-related deaths. Although nosocomial RSV deaths are expected to occur at highest rates in LMICs, the number of reported nosocomial RSV deaths was low in these countries. Hospital-based surveillance is needed to capture the full burden of nosocomial RSV mortality in LMICs.

Impact of genetic polymorphisms related to innate immune response on respiratory syncytial virus infection in children

Respiratory syncytial virus (RSV) causes lower respiratory tract infections and bronchiolitis, mainly affecting children under 2 years of age and immunocompromised patients. Currently, there are no available vaccines or efficient pharmacological treatments against RSV. In recent years, tremendous efforts have been directed to understand the pathological mechanisms of the disease and generate a vaccine against RSV. Although RSV is highly infectious, not all the patients who get infected develop bronchiolitis and severe disease. Through various sequencing studies, single nucleotide polymorphisms (SNPs) have been discovered in diverse receptors, cytokines, and transcriptional regulators with crucial role in the activation of the innate immune response, which is implicated in the susceptibility to develop or protect from severe forms of the infection. In this review, we highlighted how variations in the key genes affect the development of innate immune response against RSV. This data would provide crucial information about the mechanisms of viral infection, and in the future, could help in generation of new strategies for vaccine development or generation of the pharmacological treatments.

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

BACKGROUND

Respiratory syncytial virus (RSV) is the most common cause of acute lower respiratory infection in young children. We previously estimated that in 2015, 33·1 million episodes of RSV-associated acute lower respiratory infection occurred in children aged 0-60 months, resulting in a total of 118 200 deaths worldwide. Since then, several community surveillance studies have been done to obtain a more precise estimation of RSV associated community deaths. We aimed to update RSV-associated acute lower respiratory infection morbidity and mortality at global, regional, and national levels in children aged 0-60 months for 2019, with focus on overall mortality and narrower infant age groups that are targeted by RSV prophylactics in development.

METHODS

In this systematic analysis, we expanded our global RSV disease burden dataset by obtaining new data from an updated search for papers published between Jan 1, 2017, and Dec 31, 2020, from MEDLINE, Embase, Global Health, CINAHL, Web of Science, LILACS, OpenGrey, CNKI, Wanfang, and ChongqingVIP. We also included unpublished data from RSV GEN collaborators. Eligible studies reported data for children aged 0-60 months with RSV as primary infection with acute lower respiratory infection in community settings, or acute lower respiratory infection necessitating hospital admission; reported data for at least 12 consecutive months, except for in-hospital case fatality ratio (CFR) or for where RSV seasonality is well-defined; and reported incidence rate, hospital admission rate, RSV positive proportion in acute lower respiratory infection hospital admission, or in-hospital CFR. Studies were excluded if case definition was not clearly defined or not consistently applied, RSV infection was not laboratory confirmed or based on serology alone, or if the report included fewer than 50 cases of acute lower respiratory infection. We applied a generalised linear mixed-effects model (GLMM) to estimate RSV-associated acute lower respiratory infection incidence, hospital admission, and in-hospital mortality both globally and regionally (by country development status and by World Bank Income Classification) in 2019. We estimated country-level RSV-associated acute lower respiratory infection incidence through a risk-factor based model. We developed new models (through GLMM) that incorporated the latest RSV community mortality data for estimating overall RSV mortality. This review was registered in PROSPERO (CRD42021252400).

FINDINGS

In addition to 317 studies included in our previous review, we identified and included 113 new eligible studies and unpublished data from 51 studies, for a total of 481 studies. We estimated that globally in 2019, there were 33·0 million RSV-associated acute lower respiratory infection episodes (uncertainty range [UR] 25·4-44·6 million), 3·6 million RSV-associated acute lower respiratory infection hospital admissions (2·9-4·6 million), 26 300 RSV-associated acute lower respiratory infection in-hospital deaths (15 100-49 100), and 101 400 RSV-attributable overall deaths (84 500-125 200) in children aged 0-60 months. In infants aged 0-6 months, we estimated that there were 6·6 million RSV-associated acute lower respiratory infection episodes (4·6-9·7 million), 1·4 million RSV-associated acute lower respiratory infection hospital admissions (1·0-2·0 million), 13 300 RSV-associated acute lower respiratory infection in-hospital deaths (6800-28 100), and 45 700 RSV-attributable overall deaths (38 400-55 900). 2·0% of deaths in children aged 0-60 months (UR 1·6-2·4) and 3·6% of deaths in children aged 28 days to 6 months (3·0-4·4) were attributable to RSV. More than 95% of RSV-associated acute lower respiratory infection episodes and more than 97% of RSV-attributable deaths across all age bands were in low-income and middle-income countries (LMICs).

INTERPRETATION

RSV contributes substantially to morbidity and mortality burden globally in children aged 0-60 months, especially during the first 6 months of life and in LMICs. We highlight the striking overall mortality burden of RSV disease worldwide, with one in every 50 deaths in children aged 0-60 months and one in every 28 deaths in children aged 28 days to 6 months attributable to RSV. For every RSV-associated acute lower respiratory infection in-hospital death, we estimate approximately three more deaths attributable to RSV in the community. RSV passive immunisation programmes targeting protection during the first 6 months of life could have a substantial effect on reducing RSV disease burden, although more data are needed to understand the implications of the potential age-shifts in peak RSV burden to older age when these are implemented.

FUNDING

EU Innovative Medicines Initiative Respiratory Syncytial Virus Consortium in Europe (RESCEU).

Implications of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Pandemic on the Epidemiology of Pediatric Respiratory Syncytial Virus Infection

Respiratory viral infections account for a large percentage of global disease and death. Respiratory syncytial virus is a seasonal virus affecting immunologically vulnerable populations, such as preterm newborns and young infants; however, its epidemiology has changed drastically during the coronavirus disease 2019 pandemic. In this perspective, we discuss the implications of coronavirus disease 2019 on respiratory syncytial virus seasonality patterns and mitigation efforts, as well as the urgent need for vaccination as a preventive tool.

Predictors of poor outcomes of respiratory syncytial virus acute lower respiratory infections in children under 5 years of age in a middle-income tropical country based on the National Public Health Surveillance System

OBJECTIVES

The aim of the present study is to gain insight into the identification of region-specific factors associated with poor outcomes in children under 5 years of age with confirmed respiratory syncytial virus acute lower respiratory infection (RSV-ALRI) living in Colombia, a middle-income country, based on the National Public Health Surveillance System of the country.

METHODS

An analytical cross-sectional study was conducted using epidemiological data from the records of morbidity and mortality of respiratory infections as registered in the surveillance system report of the National Institute of Health of Colombia 2018, including children under 5 years of age with confirmed RSV-ALRI. Predictor variables included demographic and clinical variables, as well as variables measured after hospital attendance. Outcome variables analyzed were respiratory failure, the need for pediatric intensive care unit admission, and mortality.

RESULTS

Of a total of 8470 patients with a diagnosis of ALRI, we selected 1215 (14.3%) that were under 5 years of age and were positive for RSV. After controlling for potential confounders, it was found that age, gender, socioeconomic stratum, incomplete pneumococcal conjugate vaccine 13 immunization for age, cardiac disease, and malnutrition as comorbidities, chest X-ray findings, and development of sepsis independently predicted poor outcomes among the patients analyzed.

CONCLUSIONS

The identified predictors for poor outcomes in RSV-affected children may be helpful for guiding efficient and targeted national and/or regional programs and public policies to assist in achieving Goal 3 of the Sustainable Development Goals adopted by the United Nations in 2015.

Repurposing Probenecid to Inhibit SARS-CoV-2, Influenza Virus, and Respiratory Syncytial Virus (RSV) Replication

Viral replication and transmissibility are the principal causes of endemic and pandemic disease threats. There remains a need for broad-spectrum antiviral agents. The most common respiratory viruses are endemic agents such as coronaviruses, respiratory syncytial viruses, and influenza viruses. Although vaccines are available for SARS-CoV-2 and some influenza viruses, there is a paucity of effective antiviral drugs, while for RSV there is no vaccine available, and therapeutic treatments are very limited. We have previously shown that probenecid is safe and effective in limiting influenza A virus replication and SARS-CoV-2 replication, along with strong evidence showing inhibition of RSV replication in vitro and in vivo. This review article will describe the antiviral activity profile of probenecid against these three viruses.

Identifying the research, advocacy, policy and implementation needs for the prevention and management of respiratory syncytial virus lower respiratory tract infection in low- and middle-income countries

INTRODUCTION

The high burden of respiratory syncytial virus (RSV) infection in young children disproportionately occurs in low- and middle-income countries (LMICs). The PROUD (Preventing RespiratOry syncytial virUs in unDerdeveloped countries) Taskforce of 24 RSV worldwide experts assessed key needs for RSV prevention in LMICs, including vaccine and newer preventive measures.

METHODS

A global, survey-based study was undertaken in 2021. An online questionnaire was developed following three meetings of the Taskforce panellists wherein factors related to RSV infection, its prevention and management were identified using iterative questioning. Each factor was scored, by non-panellists interested in RSV, on a scale of zero (very-low-relevance) to 100 (very-high-relevance) within two scenarios: (1) Current and (2) Future expectations for RSV management.

RESULTS

Ninety questionnaires were completed: 70 by respondents (71.4% physicians; 27.1% researchers/scientists) from 16 LMICs and 20 from nine high-income (HI) countries (90.0% physicians; 5.0% researchers/scientists), as a reference group. Within LMICs, RSV awareness was perceived to be low, and management was not prioritised. Of the 100 factors scored, those related to improved diagnosis particularly access to affordable point-of-care diagnostics, disease burden data generation, clinical and general education, prompt access to new interventions, and engagement with policymakers/payers were identified of paramount importance. There was a strong need for clinical education and local data generation in the lowest economies, whereas upper-middle income countries were more closely aligned with HI countries in terms of current RSV service provision.

CONCLUSION

Seven key actions for improving RSV prevention and management in LMICs are proposed.

Evaluation of respiratory complications in a cohort of preterm infants who did not receive palivizumab monoclonal antibodies

ABSTRACT Objectives: to analyze the occurrence of respiratory complications over the first year of life in preterm infants who did not receive palivizumab monoclonal antibodies. Methods: analytical retrospective cohort study with preterm infants born between 2012 and 2016 in Uberlândia, state of Minas Gerais, Brazil. Data collection occurred from January to November 2018, by consulting hospital and primary healthcare medical records. Data were processed with the Poisson regression model, with p<0.05. Results: of a total of 5,213 preterm births, 504 (9.7%) met the inclusion criteria. The preterm infants in this subset were assisted 2,899 times in primary care, which resulted in 1,098 (37.5%) medical diagnoses, of which 803 (78.5%) involved the respiratory tract. Preterm babies fed on formula milk at hospital discharge had more diagnoses of respiratory diseases. Maternal age (p=0.039), respiratory diagnosis at hospital discharge (p=0.028), and number of sporadic appointments (p<0.001) showed a significant association with bronchiolitis; number of sporadic appointments showed a significant association with occurrence of respiratory diseases; and breastfeeding had a protective effect against the development of bronchiolitis. Conclusions: preterm infants who did not receive palivizumab showed a high percentage of respiratory diseases, and breastfeeding helped protect them against bronchiolitis. It is recommended that these preterm babies be monitored in primary health care.