Excellence in Pediatrics is a non-profit global network dedicated to advancing pediatric healthcare.
Rue des Vignerons 18, 1110 Morges 1 (VD), Switzerland
email: secretariat@ineip.org
tel. +41 43 21 55 937
Evidence, Strategy & Policy for RSV Prevention in the First Years of Life
Respiratory syncytial virus (RSV) is one of the most common and serious respiratory viruses affecting infants and young children worldwide. Every year, it causes tens of millions of lower respiratory tract infections, more than three million hospitalizations in children under five, and thousands of deaths globally. In Europe alone, RSV is responsible for more than 200,000 hospitalizations annually in children, with over 75% occurring in infants under one year of age. Yet for decades, prevention options were limited, and the virus was widely dismissed as little more than a common cold.
That has changed fundamentally. A new generation of prevention tools has demonstrated high efficacy in clinical trials and, crucially, in real-world settings across multiple countries. These include long-acting monoclonal antibodies, laboratory-produced proteins that provide immediate passive protection against RSV, and a maternal vaccine, administered during pregnancy to transfer protective antibodies to the newborn. In countries where these tools have been implemented with high coverage, RSV-associated hospitalizations have fallen by more than 80%.
This policy report, grounded in current scientific evidence and expert discussions held at the 17th Excellence in Pediatrics Conference and the 10th LifeCourse Prevention Summit, both organized in Paris in December 2025, presents a comprehensive, evidence-based review and policy recommendations for RSV prevention in infants and young children. It draws on epidemiological data, clinical trial results, real-world effectiveness studies, and the lived experiences of families affected by RSV.
It also addresses the important and under-recognized interaction between RSV and pneumococcal disease, which reinforces the case for prevention beyond bronchiolitis and hospitalization alone.
Respiratory syncytial virus is the leading cause of lower respiratory tract infection in infants and young children worldwide. Every year, it is estimated that RSV causes 33 million episodes of lower respiratory tract infection in children under five years of age, resulting in more than three million hospitalizations and over 100,000 deaths in this age group alone.
In Europe, the burden is substantial and well-documented: more than 200,000 children are hospitalized annually due to RSV, with over 75% of admissions occurring in infants under one year of age. RSV is the most common cause of bronchiolitis, accounting for up to 80% of cases, and is a major driver of both emergency department visits and pediatric intensive care unit admissions across all income settings.
The virus follows a predictable but geographically variable seasonal pattern. In the northern hemisphere, RSV typically peaks between September and January, sometimes extending to mid-March. In the southern hemisphere, circulation is concentrated between March and June, while in tropical and subtropical climates, the peak aligns closely with the rainy season or periods of higher temperature.
This seasonality has direct implications for prevention planning, as it determines the window within which protective interventions must be administered to be effective.
One of the most important and often overlooked aspects of RSV epidemiology is that the majority of severe cases, including the majority of hospitalizations and pediatric intensive care admissions, occur in otherwise healthy, full-term infants. This is not a virus that confines its most serious consequences to the most medically fragile. Data from multiple countries consistently show that when the total population of hospitalized infants is examined, healthy full-term babies represent the largest single group.
This has profound implications for prevention policy. A strategy that targets only high-risk infants will, by definition, leave the majority of vulnerable children unprotected. The data support the need for extended protection of all infants, not only those who can be identified in advance as being at elevated clinical risk.
The burden of RSV also extends well beyond the hospital. Data from the United States and European countries demonstrate high rates of outpatient visits and emergency care attendances in the first year of life attributable to RSV. These visits represent a significant and often underestimated component of the overall healthcare burden, consuming clinical time and resources across primary and secondary care settings alike.
A further dimension of RSV epidemiology with direct policy relevance is the relationship between birth timing and hospitalization risk. Analysis of hospitalization data from multiple European countries reveals that roughly half of all infants hospitalized with RSV were born before the RSV season began, while the other half were born during the season itself.
Data from France and Spain, for example, show that although the distribution varies slightly by country, the proportion of infants born in- and out-of-season is consistently close to 50%.
This finding is critical. It demonstrates that a prevention strategy focused exclusively on infants born during the RSV season will miss approximately half of those at risk. Universal protection strategies — those that cover all infants regardless of when they were born — are therefore not merely preferable but necessary if the goal is to achieve meaningful reductions in the overall burden of hospitalization.
Real-world evidence from Spain and Italy has confirmed this principle in practice. In the Galicia region of Spain, a universal prevention program achieved coverage rates exceeding 88% in infants born out of season and over 95% in those born during the season.
The consequences of RSV infection in early life are not confined to the acute episode. RSV bronchiolitis during the first six months of life is associated with an increased risk of pneumonia and acute otitis media, along with a higher likelihood of antibiotic use in the subsequent six months. This pattern reflects the biological interaction between RSV and bacterial pathogens, particularly Streptococcus pneumoniae.
Over the longer term, infants who acquire RSV in their first year of life incur significantly greater healthcare resource utilization in the years that follow compared with children who were not infected. RSV infection is associated with recurrent wheezing and an elevated risk of developing asthma, though the precise mechanisms remain areas of active research. The economic consequences are correspondingly significant, compounded by indirect costs including parental absence from work and the ongoing healthcare needs of children with post-RSV respiratory complications.
Epidemiological figures and healthcare cost analysis, however comprehensive, do not fully capture what RSV means to the families it affects. The burden of this virus is not only systemic; it is deeply personal, and it endures long after the acute infection has resolved.
Rachel Thomas, a mother, RSV advocate, university lecturer, and member of ResViNet, shared her family's experience at the Excellence in Pediatrics Conference. Her son Alexander, a healthy baby born at term, contracted RSV at thirteen weeks of age. Despite receiving medical attention, he died in the early hours of 5 February 2010. He was too small, and the virus was too powerful. More than fifteen years later, the consequences of that loss continue to shape every member of her family.
Alexander's story is not unique. In 2023, Rachel Thomas' nephew, Tobias, became critically ill with RSV at seven months of age. Another family — that of Brenda — experienced a similar trajectory: her son Thomas contracted RSV at three weeks of age and spent three weeks on life support. He survived, but relies on inhalers and medication, reacts to environmental triggers such as cold air and dust, misses school frequently due to fatigue, and has been recommended an extra year in kindergarten. His doctor has explained that he uses so much energy simply to breathe that there is less available for learning.
The financial, social, and emotional toll on families is substantial. Parents of severely affected children report stopping work, avoiding public gatherings, and experiencing persistent anxiety during the winter season. These consequences, while not routinely captured in health economic analyses, are a significant dimension of RSV's broader burden and must be considered in prevention policy.
"Here we are in 2025, nearly 16 years after my own son's death, and many still have no concept of RSV or its devastating impact. How do we expect immunization programs to work if people do not understand what they are being protected against?"— Rachel Thomas, ReSViNET Foundation
To understand the interaction between RSV and Streptococcus pneumoniae, it is necessary to first appreciate how early and how ubiquitously pneumococcal colonization occurs in infants. The nasopharynx has traditionally been considered the primary reservoir of pneumococcus, though colonization also occurs in the oropharynx and saliva.
The timing and intensity of colonization vary considerably by setting. Data from Finland showed colonization beginning as early as two weeks of life. In contrast, data from Papua New Guinea showed that 40% of infants were already carrying Streptococcus pneumoniae within the first two weeks of life. Studies from Gambia demonstrated not only rapid colonization but also the simultaneous carriage of multiple serotypes, which increases the probability of developing disease.
Understanding colonization patterns is therefore essential to explain how pneumococcal disease develops, and why certain viral infections — RSV in particular — can accelerate the progression from colonization to serious illness.
The interaction between RSV and pneumococcus has implications that run in both directions. Pneumococcal conjugate vaccines, by reducing pneumococcal colonization and disease, have been associated with reductions in RSV-associated pneumonia. A landmark study in South Africa using a nine-valent conjugate vaccine demonstrated a 32% decrease in RSV-associated pneumonia in HIV-negative children — a significant finding given that the vaccine was targeting a bacterium, not a virus.
Conversely, reducing RSV circulation through monoclonal antibodies and maternal vaccination is likely to reduce the biological conditions that facilitate pneumococcal disease. This bidirectional relationship means RSV prevention should not be evaluated solely on the basis of bronchiolitis or RSV-specific hospitalization rates. Its potential to reduce the broader burden of pneumococcal disease — including pneumonia, otitis media, and antibiotic consumption — must also be factored into assessments of value.
The effectiveness of any RSV prevention strategy is not fixed — it is a direct function of the coverage achieved. This relationship between coverage and population-level impact is one of the most important practical lessons to emerge from the first seasons of broad RSV prevention implementation.
For monoclonal antibodies, the data indicate that a coverage threshold of at least 70% is required to achieve a reduction in RSV-associated hospitalizations of more than 80% at the population level. At 60% coverage, the reduction falls to approximately 50%.
For maternal vaccination, a coverage of at least 70% is similarly needed to produce meaningful population-level results, and this threshold has proven difficult to reach consistently in many settings, including high-income countries with established antenatal care systems.
Achieving these coverage thresholds requires not only investment in the prevention products themselves but also in the outreach, communication, and health system capacity needed to reach eligible infants consistently.
"Unless you are taking a baby to the hospital, other practitioners don't know enough about RSV, or it's just a bit of a cold. Not every parent has the ability to question. They trust their doctors, as they should."— Rachel Thomas, ReSViNET Foundation
Primary care providers — general practitioners, pediatricians, midwives, and nurses — are the front line of RSV prevention. They are the professionals most likely to have contact with pregnant women and young infants, and they are the professionals whose recommendations carry the greatest weight with families.
Yet the evidence suggests that awareness of RSV and confidence in advising on its prevention remain uneven across this workforce. General practitioners and midwives, in particular, may have limited exposure to the current evidence on RSV burden and prevention.
Addressing this gap requires investment in continuing professional education that reaches beyond pediatric specialists to include the full range of primary care providers. ReSViNET has developed a learning hub with free, downloadable materials specifically designed for midwives and general practitioners. Structured educational programs, integrated into continuing medical education frameworks and supported by professional societies, are needed to bring consistent, evidence-based RSV awareness to every healthcare professional who interacts with pregnant women and young infants.
Any cost comparison must also account for the operational costs of introducing a new type of program. Maternal vaccination can be integrated into existing antenatal care structures with relatively modest additional investment, while a universal monoclonal antibody program for newborns requires new delivery pathways, staff training, and logistical infrastructure.
The cost of failing to prevent RSV is substantial. The direct costs of RSV hospitalizations, intensive care admissions, and outpatient visits; the indirect costs of parental absence from work; the longer-term costs of post-RSV respiratory complications; and the system costs of cancelled elective surgeries and diverted critical care resources during peak RSV season all represent a significant and largely avoidable burden.
In Ireland, prior to the introduction of a universal prevention program, RSV routinely resulted in infants being transferred by ambulance to Dublin, intubated and ventilated, and in the cancellation of elective pediatric surgeries, including cardiac operations. In the first season following program introduction, critical care transport of infants for respiratory conditions fell by approximately 90%.
High-income countries in Europe, North America, and parts of the Asia-Pacific region are implementing universal or near-universal prevention programs, reporting dramatic reductions in hospitalizations. Meanwhile, 97% of RSV-related deaths in children occur in low- and middle-income countries, where monoclonal antibodies remain entirely out of reach and maternal vaccination programs are only beginning to be considered.
The countries now benefiting most from RSV prevention are precisely those where the burden of death is lowest. India alone accounts for approximately 25 million births annually. If the reductions in RSV morbidity achieved in Europe are not extended to settings of this scale, global RSV mortality will remain largely unchanged even as the burden in high-income countries falls dramatically.
There are reasons for cautious optimism. A recent meeting of Gavi, the Vaccine Alliance, considered a maternal immunization program specifically designed for low- and middle-income countries. Maternal vaccination, with its lower unit cost and compatibility with existing antenatal infrastructure, may prove to be the most viable entry point for RSV prevention in resource-limited settings.
The evidence presented in this report points consistently in one direction: RSV is a serious and preventable disease, effective prevention tools are available, and the principal remaining challenge is one of implementation, coverage, awareness, and equity. The recommendations that follow are directed at clinicians, health system leaders, and policymakers at national and international level. They are organized around five priorities: universal protection, professional education, public awareness, research and surveillance, and global equity.
The primary policy recommendation that emerges from the current evidence is the adoption of universal RSV prevention strategies for all infants in their first RSV season, regardless of gestational age, birth timing, or underlying health status.
A combined strategy offering both maternal vaccination during pregnancy and monoclonal antibodies for all newborns represents the most comprehensive approach, as demonstrated by the Luxembourg experience.
Monoclonal antibodies offer the most reliable route to high and consistent coverage across all birth timings and risk profiles. Coverage of at least 70% is needed to produce meaningful population-level reductions in hospitalization.
Maternal vaccination is an effective and lower-cost alternative in settings with well-functioning antenatal immunization infrastructures, but must be accompanied by active efforts to reach coverage levels above 70%. High-risk infants should receive monoclonal antibodies regardless of maternal vaccination status.
Programs must explicitly cover infants born out of season as well as those born during the RSV season. The evidence consistently shows that approximately half of hospitalized infants are born out of season, and universal strategies are the only reliable way to protect this group.
"For immunization programs to truly succeed, the public needs to feel informed and empowered. Open, honest conversations matter — conversations where parents feel heard, where their concerns are taken seriously, and where they have the information needed to make the best decisions for their children."— Rachel Thomas, ReSViNET Foundation
"If we are talking about 25 million annual births in India alone, and we just reduce the morbidity from RSV in Europe, the global mortality is not going to come down. Equity is extremely paramount when you talk about an immunization program."— Roy Philip
These figures are almost certainly underestimates. The diagnostic tools most commonly used in clinical practice — primarily nasopharyngeal swabs — significantly underrepresent the true prevalence of RSV infection. When additional samples such as saliva and serum are incorporated, the number of positive tests can double.
The consequences of RSV infection in older adults extend well beyond the respiratory system. Immunosenescence — the progressive deterioration of immune function with age — means that older adults are not only more susceptible to RSV infection but also more likely to experience more severe and more prolonged illness.
Studies conducted in Denmark and Scotland have shown that adults with chronic obstructive pulmonary disease, ischemic heart disease, stroke, or diabetes face a two to four-fold higher risk of RSV-associated respiratory hospitalization. Among adults hospitalized with RSV, one in five experiences an acute cardiac event — most commonly acute heart failure. In those with pre-existing cardiovascular conditions, this rises to one in three.
For older adults, RSV infection also initiates or accelerates a vicious cycle of functional decline. Each episode of severe respiratory illness can result in loss of physical capacity, cognitive deterioration, and reduced autonomy, increasing the need for long-term care and placing additional strain on family caregivers.
Recurrent infections are particularly common in older adults. Immunosenescence increases the severity of infections and leads to repeated episodes, creating a vicious cycle that can result in early complications, worsening of pre-existing conditions, and progressive decline in physical and cognitive function.
Several RSV vaccines are now approved for use in older and high-risk adult populations, and each has demonstrated effectiveness in reducing RSV-associated hospitalizations and the systemic complications that follow. In Germany, the Standing Committee on Vaccination recommends RSV vaccination for all adults over the age of 75.
Despite the availability of these tools, coverage among older adults remains strikingly low across Europe. For COVID-19 vaccination, coverage in the European population over 60 has fallen to approximately 14%. RSV vaccination for older adults is, in most countries, not yet reimbursed or included in national immunization programs.
"The vaccines at the right time would be a booster for our immune system, and we could somehow modulate immunosenescence by having a life course approach to vaccination. Lifelong integrated immunization should be the strategy that truly matches the biology of risk."— Stefania Maggi
"For the first time we have a safe and effective arsenal capable of supporting healthy ageing by protecting every generation — from infancy, or starting with maternal immunization, to older age. We should really do our best to translate the data into actions."— Marco Del Riccio
