Cost-Effectiveness of Respiratory Syncytial Virus Preventive Interventions in Children: A Model Comparison Study

Cost-effectiveness of bivalent respiratory syncytial virus Prefusion F (RSVpreF) maternal vaccine among infants in the United States

BACKGROUND

Respiratory syncytial virus (RSV) is a leading cause of respiratory tract illness (RTI) among young children. The novel bivalent stabilized prefusion F subunit vaccine (RSVpreF) for pregnant people to protect their infants against RSV lower respiratory tract illness (RSV-LRTI) was recommended by the US Advisory Committee on Immunization Practices for use among pregnant persons between 32 and 36 weeks of gestation in September 2023. We evaluated the cost-effectiveness of maternal RSVpreF for prevention of RSV among US infants.

METHODS

A cohort model was employed to depict clinical outcomes and economic costs of RSV from birth to age 1 year and lifetime consequences of premature RSV-related death. Cost-effectiveness of year-round and, alternatively, seasonally administered RSVpreF was evaluated compared to no intervention. Model inputs include RSV disease and case-fatality rates; vaccine effectiveness (derived from trial analyses); and costs of RSVpreF, RSV treatment, and caregiver work loss. Clinical outcomes (projected monthly) included cases of medically attended RSV, RSV-LRTI deaths, and quality-adjusted LYs (QALYs). Economic costs were generated based on vaccines administered as well as cases and corresponding unit costs and were reported in 2023 US$. Costs and benefits were discounted 3 % annually.

RESULTS

Year-round maternal vaccination with RSVpreF resulted in a reduction of 13,349 hospitalizations, 32,414 emergency department encounters, and 96,540 outpatient clinic visits, corresponding with an increase in direct medical costs of $366 million and decrease in indirect (non-medical) costs of $80 million. With 2264 additional QALYs, the cost-effectiveness ratio was $89,733/QALY. Seasonal maternal vaccination prevented 23-39 % fewer cases (care setting dependent), but was cost saving overall, resulting in a dominant cost-effectiveness ratio.

CONCLUSION

Maternal vaccination with RSVpreF would substantially reduce the clinical and economic burden of RSV in infants, resulting in a cost-effectiveness ratio of $89,733 per QALY if administered year-round or cost savings if administered seasonally.

Evaluation of the costs of care for pediatric patients hospitalized for RSV: A retrospective cohort study in Belgium

INTRODUCTION

This study aimed to evaluate the costs of respiratory-syncytial virus (RSV)-related hospitalizations in children under 3 years old in Belgium for hospitals and health insurance, and to identify factors influencing costs.

METHODS

This retrospective cohort study used data from 16 French-speaking hospitals in Belgium, covering January 1, 2018, to December 31, 2019. RSV diagnoses for children under three were identified using International Classification of Diseases-Tenth Revision (ICD-10) codes, resulting in 2176 hospitalizations analyzed for cost assessment. Hospital and health insurance costs were derived from administrative and billing data, adjusted for inflation, and analyzed using descriptive and inferential statistics, including regression models to assess cost factors.

RESULTS

Of the 2176 RSV-related hospitalizations, 61.8 % were in children under one year, and 74.1 % had readmissions within a year. The median length of stay (LOS) was 3.67 days, with a median hospital cost of €2924 and a median health insurance cost of €2221 per stay. Factors associated with higher costs included longer LOS, severe diagnosis-related group category, pediatric intensive care unit admission, and non-invasive ventilation use, with costs generally lower for children aged 1-2 years. Based on these data, the annual costs in Belgium associated with RSV hospitalizations in the pre-immunization era are estimated to exceed €26 million from the health insurance perspective and €29 million from the hospital perspective.

CONCLUSION

This study highlights the significant and underestimated financial burden of RSV hospitalization in Belgium. This emphasizes the need for better resource allocation to reduce the economic impact of RSV on healthcare systems.

Cost-Effectiveness Analysis of Nirsevimab for Preventing Respiratory Syncytial Virus-Related Lower Respiratory Tract Disease in Dutch Infants: An Analysis Including All-Infant Protection

OBJECTIVES

This study aimed to assess the cost effectiveness of nirsevimab, a recently authorized monoclonal antibody (mAb) for the prevention of lower respiratory tract disease (LRTD) caused by respiratory syncytial virus (RSV), in comparison with the standard practice involving palivizumab for high-risk infants during their first RSV season in the Netherlands.

METHODS

A static cost-effectiveness model was populated for the Netherlands to evaluate different immunization strategies for nirsevimab over a single RSV season from a societal perspective. The model considered the most recently published RSV incidence data (average incidence from 2006 to2018), costs (adjusted to the 2023 price year), and associated health effects. Extensive scenario analyses were conducted to explore various strategies, and sensitivity analysis was performed to assess the model's robustness.

RESULTS

In the base-case scenario, all-infant protection-a strategy of in-season with catch-up immunization for all infants-nirsevimab has the potential to prevent numerous RSV-related cases, including 2333 hospitalizations and 150 intensive-care admissions, in the overall population compared with the standard of care. Nirsevimab appears to be cost effective under this strategy with an economically justifiable acquisition price for nirsevimab of €220 at a willingness-to-pay threshold of €50,000 per quality-adjusted life-year. Sensitivity analyses indicate a 52% probability that nirsevimab is cost effective at this threshold. Comparison of different vaccination strategies revealed that the all-infant protection approach was the one that prevented the higher number of cases.

CONCLUSIONS

This study indicates that universal infant immunization with nirsevimab has the potential to be cost effective and significantly reduces the burden of RSV among Dutch infants. These findings underscore the importance of implementing effective protective measures against RSV-LRTD, reducing the pressure on the healthcare system during the RSV season.

Cost-savings and health impact of strategies for prevention of Respiratory Syncytial Virus with nirsevimab in Chile based on the integrated analysis of 2019-2023 national databases: A retrospective study

BACKGROUND

In the latter half of 2023, the northern hemisphere initiated the rollout of nirsevimab immunization strategies for infants, yielding promising early results. As Chile prepared for its 2024 strategy implementation, we retrospectively evaluated the potential cost-saving nature of various immunization strategies.

METHODS

Leveraging comprehensive inpatient, outpatient, and sentinel programs data, we conduct a simulation-based retrospective analysis to evaluate the net cost savings of various immunization strategies based on nirsevimab. We first characterize RSV burden among Chilean infants between 2019 and 2023, focusing on medically attended lower respiratory tract infections (MA LRTI), hospital admissions (HA LRTI), and severe cases requiring ICU admission (ICU LRTI). Utilizing nirsevimab efficacy estimates, we simulate counterfactual scenarios to estimate reductions in outpatient visits, hospitalizations, and ICU admissions had nirsevimab been used. We evaluate diverse immunization strategies and estimate their cost-saving status.

FINDINGS

With nirsevimab costing about USD$225 per dose, immunizing infants under 6 months before the RSV season, all newborns during the season, and high-risk groups would have been cost-saving in 2023 and 2019. This strategy would have significantly decreased the strain on the healthcare system during the seasonal surge, reducing 13,533 ICU (77·81/1000 live newborns) and 27,465 hospital bed requirements (157·91/1000 live newborns), alongside 46,886 emergency room visits (269·58/1000 live newborns).

INTERPRETATION

In Chile, a country with a GDP per capita of USD$17,000, various immunization strategies are cost-saving for scenarios comparable to pre-pandemic 2019 and to the particularly severe 2023 when considering only those direct costs associated with patient care, albeit differing in their impact in health outcomes. The resulting decrease in healthcare strain during the Winter virus surge underscores the strategy's impact.

Impact of RSVpreF vaccination on reducing the burden of respiratory syncytial virus in infants and older adults

Respiratory syncytial virus (RSV) causes a substantial health burden among infants and older adults. Prefusion F protein-based vaccines have shown high efficacy against RSV disease in clinical trials, offering promise for mitigating this burden through maternal and older adult immunization. Employing an individual-based model, we evaluated the impact of RSV vaccination on hospitalizations and deaths in 13 high-income countries, assuming that the vaccine does not prevent infection or transmission. Using country-specific vaccine uptake rates for seasonal influenza, we found that vaccination of older adults would prevent hospitalizations by a median of 35-64% across the countries studied here. Vaccination of pregnant women could avert infant hospitalizations by 5-50%. Reductions in RSV-related mortality mirrored those estimated for hospitalizations. While substantial hospitalization costs could be averted, the impact of vaccination depends critically on uptake rates. Enhancing uptake and accessibility is crucial for maximizing the real-world impact of vaccination on reducing RSV burden among vulnerable populations.

Health Preferences in Transition: Differences from Pandemic to Post-Pandemic in Valuation of COVID-19 and RSV Illness in Children and Adults

Objective: This study aimed to measure changes in preferences regarding health-related quality of life associated with COVID-19 and RSV illness in children and adults from 2021 (during the COVID-19 pandemic) to 2023 (post-pandemic). Methods: A stated-preference survey elicited time trade-off (TTO) values from US adults in spring 2021 (n = 1014) and summer 2023 (n = 1186). Respondents were asked to indicate how much time they would hypothetically be willing to trade from the end of their life to avoid the effects of varying severities of COVID-19 and RSV illness for: (1) children; (2) parents of an ill child (family spillover); and (3) adults. Attitudes relating to COVID-19 vaccination and data on experience with COVID-19 or RSV illness were also collected. The primary outcome measure was the loss in quality-adjusted life years (QALYs). Changes in preferences over the time period from 2021 to 2023 were evaluated using regression analysis. Results: QALY losses increased with disease severity and were highest for Long COVID. Across all COVID-19 and RSV health states, QALY losses associated with child health states were higher than family spillover or adult health states. In the regression analysis, QALY losses reported in the 2023 survey were significantly lower than 2021 QALY losses for COVID-19, but not RSV. Conclusions: Preferences may change over time in a pandemic context and therefore, economic analyses of pandemic interventions should consider the timeframe of health preference data collection to determine whether they are suitable to include in an economic evaluation. Even with the impacts on health-related quality of life attenuated over time, childhood illnesses still had a measurable impact on caregivers' quality of life.

Economic and Clinical Benefits of Bivalent Respiratory Syncytial Virus Prefusion F (RSVpreF) Maternal Vaccine for Prevention of RSV in Infants: A Cost-Effectiveness Analysis for Mexico

BACKGROUND/OBJECTIVES

Respiratory syncytial virus (RSV) is a leading cause of respiratory infections in children. A novel RSVpreF vaccine for use among pregnant women for the prevention of RSV in infants is expected to be licensed in Mexico. Hence, the clinical and economic burden of RSV among infants in Mexico, with and without a year-round RSVpreF maternal vaccination program, was estimated.

METHODS

A cohort model was developed to project clinical and economic outcomes of RSV from birth to 1 year of age for maternal vaccination and no intervention. Incremental cost-effectiveness ratios were calculated from direct cost outcomes, life years, and quality-adjusted life years (QALYs). The value per dose of the RSVpreF for which the program would be cost-effective was explored. Analyses were conducted from the healthcare system perspective, with direct costs (2024 Mexican Pesos [MXN]) and outcomes discounted at 5% annually; scenario and sensitivity analyses tested the robustness of model settings and inputs.

RESULTS

Compared to no intervention, a year-round RSVpreF vaccine administered to 1891 M pregnant women would prevent 15,768 hospitalizations, 5505 emergency department cases, and 5505 physician office visits annually, averting MXN 1754 M in direct medical costs with an increase of 3402 life years or 3666 QALYs. The RSVpreF vaccine would be cost-saving up to MXN 1301/dose and cost-effective up to MXN 2105-MXN 3715/dose under an assumed cost-effectiveness threshold range of 1-3× the gross domestic product (GDP) per capita (MXN 247,310) per QALY gained.

CONCLUSIONS

Year-round RSVpreF maternal vaccination would substantially reduce RSV's clinical and economic burden among infants in Mexico and likely be a cost-effective program.

Impact of Respiratory Syncytial Virus (RSV) in Adults 60 Years and Older in Spain

Background/Objectives: Respiratory illnesses frequently lead to hospitalization in adults aged 60 and older, especially due to respiratory viral infectious (RVI). This study investigates hospitalization patterns and characteristics of RVI at HM Hospitals from October 2023 to March 2024; Methods: We retrospectively explored hospitalizations of patients aged 60 years and older with RVIs, gathering data on demographics, clinical profiles, comorbidities, and treatments. Outcomes included hospitalization, ICU admissions, and mortality, and independent factors associated with outcomes were identified using a multi-state model; Results: From October 2023 to March 2024, from a total of 3258 hospitalizations, 1933 (59.3%) were identified as positive for RVIs. Overall, SARS-CoV-2 was the most prevalent (52.6%), followed by influenza (32.7%), and RSV (11.8%). Most RVI involved single infections (88.2%). Hospitalization rates increased with age for SARS-CoV-2 (333.4 [95% CI: 295.0-375.2] to 651.6 [95% CI: 532.1-788.4]), influenza (169.8 [95% CI: 142.6-200.7] to 518.6 [95% CI: 412.1-643.1]), and RSV (69.2 [95% CI: 52.2-90.0] to 246.0 [95% CI: 173.8-337.5]), with SARS-CoV-2 showing the highest rate, followed by influenza and RSV. In the multi-state model, RSV infection significantly increased ICU admission risk (HR: 2.1, 95%, p = 0.037). Age on admission (HR: 1.1, 95%, p < 0.001) and Charlson score (HR: 1.4, 95%, p = 0.001) were associated with transitioning from admission to death. ICU to death risks included age at admission (HR: 1.7, 95%, p < 0.001); Conclusions: RVI in adults 60 years and older are associated with high hospitalization and mortality rates, primarily driven by influenza and SARS-CoV-2, followed by RSV. Age and comorbidities significantly impact disease severity, emphasizing the need for targeted prevention and management strategies for RSV in this vulnerable population.

Evaluating the Effectiveness of Nirsevimab in Reducing Pediatric RSV Hospitalizations in Spain

Background/Objectives: Respiratory syncytial virus (RSV) is a major cause of hospitalization in infants. Nirsevimab has demonstrated to be a promising tool for preventing severe RSV disease. Although clinical trials have demonstrated the efficacy of Nirsevimab in preventing severe RSV disease, evidence regarding its performance in real-world clinical settings is still limited due to its recent introduction. This study aims to fill this knowledge gap by evaluating the impact of Nirsevimab in a cohort of infants and determining its effectiveness in reducing the burden of RSV disease. Methods: A retrospective study of RSV hospitalizations was conducted in children under six months of age, between 1 October and 31 March, across four seasons: pre-COVID (2018-2019), COVID (2019-2020), post-COVID pre-Nirsevimab (2022-2023), and Nirsevimab season (2023-2024). Results: Nirsevimab demonstrated significant efficacy in reducing RSV-related hospitalizations in infants under six months of age. During the 2023/2024 season, following the introduction of Nirsevimab, there was a substantial reduction in RSV-related lower respiratory tract infection (LRTI) hospitalizations. Among infants under 3 months of age, hospitalizations decreased by 79.3% (IRR: 0.21, 95% CI: 0.12-0.34). In infants aged 3 to 6 months, there was a 66.9% reduction (IRR: 0.33, 95% CI: 0.15-0.64). Additionally, Nirsevimab decreased the severity of RSV cases with LRTI who required the support of equipment for sanitary use, further reducing overall healthcare burden. Conclusions: These results underscore Nirsevimab's vital role in preventing severe RSV infections and hospitalizations, especially among the most vulnerable infants, positioning it as a critical advancement in pediatric respiratory care.

Cost-effectiveness Analysis of Maternal Immunization with RSVpreF Vaccine for the Prevention of Respiratory Syncytial Virus Among Infants in Spain

INTRODUCTION

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory infections (ALRI) in children under one year of age. In high-income countries, RSV infections cause a significant overload of care every winter, imposing a significant burden to the healthcare system, which has made the development of prevention strategies a major global health priority. In this context, a new bivalent RSV prefusion F protein-based vaccine (RSVpreF) has recently been approved. The objective of this study was to evaluate the cost-effectiveness of vaccinating pregnant women with the RSVpreF vaccine to prevent RSV in infants from the Spanish National Healthcare System (NHS) perspective.

METHODS

A hypothetical cohort framework and a Markov-type process were used to estimate clinical outcomes, costs, quality-adjusted life years (QALY) and cost-per-QALY gained (willingness-to-pay threshold: €25,000/QALY) for newborn infants born to RSV-vaccinated versus unvaccinated mothers over an RSV season. The base case analysis was performed from the NHS perspective including direct costs (€2023) and applying a discount of 3% to future costs and outcomes. To evaluate the robustness of the model, several scenarios, and deterministic and probabilistic analyses were carried out. All the parameters and assumptions were validated by a panel of experts.

RESULTS

The results of the study showed that year-round maternal vaccination program with 70% coverage is a dominant option compared to no intervention, resulting in direct cost savings of €1.8 million each year, with an increase of 551 QALYs. Maternal vaccination could prevent 38% of hospital admissions, 23% of emergency room visits, 19% of primary care visits, and 34% of deaths due to RSV. All scenario analyses showed consistent results, and according to the probabilistic sensitivity analysis (PSA), the probability of maternal vaccination being cost-effective versus no intervention was 99%.

CONCLUSIONS

From the Spanish NHS perspective, maternal vaccination with bivalent RSVpreF is a dominant alternative compared with a non-prevention strategy.

Comparison of a static cohort model and dynamic transmission model for respiratory syncytial virus intervention programs for infants in England and Wales

BACKGROUND

A recent study comparing results of multiple cost-effectiveness analyses (CEAs) in a hypothetical population found that monoclonal antibody (mAb) immunoprophylaxis for respiratory syncytial virus (RSV) in infants averted fewer medically attended cases when estimated using dynamic transmission models (DTMs) versus static cohort models (SCMs). We aimed to investigate whether model calibration or parameterization could be the primary driver of inconsistencies between SCM and DTM predictions.

METHODS

A recently published DTM evaluating the CEA of infant mAb immunoprophylaxis in England and Wales (EW) was selected as the reference model. We adapted our previously published SCM for US infants to EW by utilizing the same data sources used by the DTM. Both models parameterized mAb efficacy from a randomized clinical trial (RCT) that estimated an average efficacy of 74.5% against all medically attended RSV episodes and 62.1% against RSV hospitalizations. To align model assumptions, we modified the SCM to incorporate waning efficacy. Since the estimated indirect effects from the DTM were small (i.e., approximately 100-fold smaller in magnitude than direct effects), we hypothesized that alignment of model parameters should result in alignment of model predictions. Outputs for model comparison comprised averted hospitalizations and averted GP visits, estimated for seasonal (S) and seasonal-with-catchup (SC) immunization strategies.

RESULTS

When we aligned the SCM intervention parameters to DTM intervention parameters, significantly more averted hospitalizations were predicted by the SCM (S: 32.3%; SC: 51.3%) than the DTM (S: 17.8%; SC: 28.6%). The SCM most closely replicated the DTM results when the initial efficacy of the mAb intervention was 62.1%, leading to an average efficacy of 39.3%. Under this parameterization the SCM predicted 17.4% (S) and 27.7% (SC) averted hospitalizations. Results were similar for averted GP visits.

CONCLUSIONS

Parameterization of the RSV mAb intervention efficacy is a plausible primary driver of differences between SCM versus DTM model predictions.

Respiratory Syncytial Virus-Associated Hospitalizations in Children: A 10-Year Population-Based Analysis in Finland, 2008-2018

BACKGROUND

The risk of respiratory syncytial virus (RSV) hospitalization is highest during the first months of life, but few studies have assessed the population-based rates of hospitalization in monthly age groups of infants.

METHODS

We determined the average population-based rates of hospitalization with virologically confirmed RSV infections in children ≤15 years of age admitted during the 10-year period of 2008-2018. Testing for RSV was routine in all children hospitalized with respiratory infections, and all RSV-positive children admitted at any time during the study period were included in the analyses.

RESULTS

The annual population-based rate of RSV hospitalization was highest in infants 1 month of age (52.0 per 1000 children; 95% CI, 45.2-59.7), followed by infants <1 month of age (34.8 per 1000; 95% CI, 29.2-41.1) and those 2 months of age (32.2 per 1000; 95% CI, 26.9-38.4). In cumulative age groups, the rate of hospitalization was 39.7 per 1000 (95% CI, 36.2-43.4) among infants <3 months of age, 26.8 per 1000 (95% CI, 24.8-29.0) in infants aged <6 months, and 15.8 per 1000 (95% CI, 14.7-17.0) in those <12 months of age.

CONCLUSION

In monthly age groups of infants, the incidence rates of virologically confirmed RSV hospitalization in all infants up to 3 months of age were substantially higher than those reported in earlier studies. These data may be important for improving the estimates of the cost-effectiveness of various interventions to reduce the burden of RSV in young infants.

Substantial Burden of Nonmedically Attended RSV Infection in Healthy-Term Infants: An International Prospective Birth Cohort Study

BACKGROUND

During the first year of life, 1 in 4 infants develops a symptomatic respiratory syncytial virus (RSV) infection, yet only half seek medical attention. The current focus on medically attended RSV therefore underrepresents the true societal burden of RSV. We assessed the burden of nonmedically attended RSV infections and compared with medically attended RSV.

METHODS

We performed active RSV surveillance until the age of 1 year in a cohort (n = 993) nested within the Respiratory Syncytial Virus Consortium in EUrope (RESCEU) prospective birth cohort study enrolling healthy term-born infants in 5 European countries. Symptoms, medication use, wheezing, and impact on family life were analyzed.

RESULTS

For 97 of 120 (80.1%) nonmedically attended RSV episodes, sufficient data were available for analysis. In 50.5% (49/97), symptoms lasted ≥15 days. Parents reported impairment in usual daily activities in 59.8% (58/97) of episodes; worries, 75.3% (73/97); anxiety, 34.0% (33/97); and work absenteeism, 10.8% (10/93). Compared with medically attended RSV (n = 102, 9 hospital admissions), Respiratory Syncytial Virus NETwork (ReSViNET) severity scores were lower (3.5 vs 4.6, P < .001), whereas duration of respiratory symptoms and was comparable.

CONCLUSIONS

Even when medical attendance is not required, RSV infection poses a substantial burden to infants, families, and society. These findings are important for policy makers when considering the implementation of RSV immunization. Clinical Trials Registration. ClinicalTrials.gov (NCT03627572).

The role of real-world evidence for regulatory and public health decision-making for Accelerated Vaccine Deployment- a meeting report

The COVID-19 pandemic underscored the need for rapid evidence generation to inform public health decisions beyond the limitations of conventional clinical trials. This report summarises presentations and discussions from a conference on the role of Real-World Evidence (RWE) in expediting vaccine deployment. Attended by regulatory bodies, public health entities, and industry experts, the gathering was a collaborative exchange of experiences and recommendations for leveraging RWE for vaccine deployment. RWE proved instrumental in refining decision-making processes to optimise dosing regimens, enhance guidance on target populations, and steer vaccination strategies against emerging variants. Participants felt that RWE was successfully integrated into lifecycle management, encompassing boosters and safety considerations. However, challenges emerged, prompting a call for improvements in data quality, standardisation, and availability, acknowledging the variability and potential inaccuracies in data across diverse healthcare systems. Regulatory transparency should also be prioritised to foster public trust, and improved collaborations with governments are needed to streamline data collection and navigate data privacy regulations. Moreover, building and sustaining resources, expertise, and infrastructure in LMICs emerged as imperative for RWE-generating capabilities. Continued stakeholder collaboration and securing adequate funding emerged as vital pillars for advancing the use of RWE in shaping responsive and effective public health strategies.

Nirsevimab for the prevention of respiratory syncytial virus disease in children. Statement of the Spanish Society of Paediatric Infectious Disease (SEIP)

INTRODUCTION

Nirsevimab, a monoclonal antibody for the prevention of disease caused by respiratory syncytial virus (RSV), has recently been approved for use in Europe and Spain.

OBJECTIVES

To provide recommendations for the administration of nirsevimab for prevention of RSV disease.

METHODS

The approach chosen to develop these recommendations involved a critical review of the literature and the use of the Delphi and GRADE methods. An expert group was formed. The group engaged in three rounds to define the questions, express support or opposition, grade recommendations and establish the agreement or disagreement with the conclusions.

RESULTS

In the general neonatal population, routine administration of nirsevimab is recommended to reduce the frequency of illness and hospitalisation for bronchiolitis and RSV lower respiratory tract infection. Nirsevimab is recommended for all infants born in high-incidence RSV season and infants aged less than 6 months at the season onset. In infants born preterm between 29 and 35 weeks of gestation, with haemodynamically significant heart disease or with chronic lung disease, routine administration of nirsevimab is recommended to reduce the incidence of disease and hospitalisation due to bronchiolitis and RSV lower respiratory tract infection. In patients in whom palivizumab is currently indicated, its substitution by nirsevimab is recommended to reduce the burden of bronchiolitis.

CONCLUSIONS

Routine administration of nirsevimab to all infants aged less than 6 months born during the RSV season or aged less than 6 months at the start of the winter season is recommended to reduce the burden of disease and the frequency of hospitalization due to bronchiolitis.