Respiratory syncytial virus (RSV) is a leading cause of severe lower respiratory tract infection among infants and older adults and represents a substantial global public health burden. Each year, RSV causes tens of millions of infections in children under five, with the highest mortality risk concentrated in infants younger than six months. Although new preventive tools—including maternal vaccines and long-acting monoclonal antibodies—have recently become available, most RSV-related deaths still occur in low- and middle-income countries, highlighting persistent inequities in access and implementation. The focus of RSV control is therefore shifting from technological feasibility toward equitable delivery and system integration.
Recent global policy developments have accelerated this transition. The World Health Organization prequalified the first maternal RSV vaccine and issued its first RSV immunization position paper, establishing a framework prioritizing maternal vaccination and long-acting monoclonal antibodies for infant protection. These recommendations emphasize country-specific strategy selection based on disease burden, health system capacity, and resource availability. In parallel, Gavi’s decision to support maternal RSV vaccine introduction during its 2026–2030 strategy period represents an important step toward improving access in resource-limited settings.
RSV prevention strategies now span the life course. In infants, maternal vaccination provides passive protection via transplacental antibody transfer, while long-acting monoclonal antibodies offer immediate protection independent of maternal immune response. Evidence from clinical trials and real-world studies demonstrates substantial reductions in RSV-associated infection and hospitalization using both approaches. In older adults, several vaccines have shown high efficacy against RSV-related disease and severe outcomes, although uptake depends on policy recommendations, risk awareness, and financing mechanisms.
Beyond preventing acute respiratory illness, RSV immunization may generate broader health benefits. Previous studies have suggested that RSV-associated lower respiratory tract infections during infancy are linked to long-term lung function impairment, recurrent wheezing, and an increased risk of chronic respiratory diseases. Implementing immunoprophylaxis early in life may improve respiratory developmental trajectories, thereby influencing long-term health outcomes. Some studies have also observed that vaccination with specified adjuvanted RSV vaccines in older adults may be associated with a reduced risk of neurodegenerative diseases; however, the underlying mechanisms require further investigation and confirmation.
The burden of RSV disease is highly uneven globally, with approximately 97% of related deaths occurring in low- and middle-income countries. Additionally, a large number of cases occur at the community level and are not adequately captured by existing surveillance systems, leading to a systematic underestimation of the disease burden. Current RSV vaccines and monoclonal antibody development rely largely on high-income country data, with limited consideration of affordability and accessibility for low- and middle-income settings, where systematic data on disease costs and community-level deaths remain insufficient. Significant barriers persist across global policy frameworks and national implementation, including slow product prequalification, weak health system capacity, and seasonal variability, all of which hinder access in resource-limited countries. Furthermore, uneven surveillance and laboratory capacity, combined with low public awareness and vaccine hesitancy, further undermine accurate burden assessment and the social acceptance of new immunization strategies.
In conclusion, RSV prevention is entering a new phase characterized by multiple immunization strategies and expanding global policy support. Achieving equitable and sustainable impact will depend on integrating RSV prevention into existing maternal, infant, and adult immunization programs, strengthening real-world evidence, and improving accessibility in high-burden settings.
Content Editor: Tianyi Deng
Page Editor: Ruitong Li
Relevant Research Papers:
1. Shaaban F, Groenendijk R, Baral R et al.The path to equitable respiratory syncytial virus prevention for infants: challenges and opportunities for global implementation.The Lancet Global Health, 2025; 13, e2165-e2174.
2. WHO position paper on immunization to protect infants against respiratory syncytial virus disease, May 2025.
3. Amin R, Darwin R, Sarma MK, et al. Maternal RSV immunization: clinical efficacy, immunological mechanisms and public health implications for preventing infant lower respiratory tract infection. J Health Popul Nutr. 2026 Feb 21;45(1):105.
4. Moulia DL, Link-Gelles R, Chu HY, et al. Use of Clesrovimab for Prevention of Severe Respiratory Syncytial Virus-Associated Lower Respiratory Tract Infections in Infants: Recommendations of the Advisory Committee on Immunization Practices – United States, 2025. MMWR Morb Mortal Wkly Rep. 2025 Aug 28;74(32):508-514.
5. Xiao Q, Yang R, Zhang L, et al. Safety and Efficacy of Respiratory Syncytial Virus Vaccination in Older Adults: Systematic Review and Meta-Analysis of Randomized Controlled Trials. JMIR Public Health Surveill. 2025 Dec 4;11:e74271.
6. Fafi I, Levy C, Birgy A, et al. Impact of RSV immunization on the rate of pediatric acute otitis media: a time-series analysis. Clin Infect Dis. 2025 Oct 9:ciaf 564.
7. Allinson JP, Chaturvedi N, Wong A, et al. Early childhood lower respiratory tract infection and premature adult death from respiratory disease in Great Britain: a national birth cohort study. Lancet. 2023;401(10380):1183-1193.
8. GAVI board focuses on health impact as priority guiding principle in a resource constrained world. (2025, July 25). Gavi. Retrieved April 10, 2026, from https://www.gavi.org/news/media-room/gavi-board-focuses-health-impact-priority-guiding-principle-resource-constrained
