Global Burden Study Highlights Underappreciated Adult RSV Hospitalizations

Katrin Burkart

Image credits: Univeristy of Washington

A multinational analysis estimates that respiratory syncytial virus (RSV) contributes substantially to adult hospitalizations, especially among those aged 60 years and older, across 15 middle- and high-income countries. Published in The Lancet Global Health (July 2025), the study points to opportunities for enhanced RSV prevention and vaccination strategies, particularly in the US, where hospitalization rates rank among the highest worldwide.

“Our findings highlight the significant role RSV plays in hospitalizations among older adults,” said Katrin Burkart, PhD, lead author and assistant professor at the University of Washington. Utilizing data from hospital and insurance records and RSV surveillance systems, Burkart’s team modeled exposure-response relationships to calculate the population-attributable fraction (PAF) of RSV-driven admissions for respiratory and cardiorespiratory diagnoses, stratified by age and region.

“In adults over 60—and especially in the 60–74 age group—a substantial proportion of respiratory and cardiorespiratory hospitalizations … are attributable to RSV,” Burkart emphasized, reinforcing current CDC guidelines recommending vaccination for adults aged ≥75 years and high-risk individuals aged 60–74. She noted, “This suggests that individuals in these age groups may face a higher risk of serious outcomes from RSV than previously recognized, confirming the importance of getting vaccinated according to current recommendations.”

The study revealed that the highest RSV-attributable hospitalization rates occurred in adults ≥75 years, up to 1,199.8 per 100,000 in New Zealand, while the lowest rates were seen in adults aged 18–59 in Spain, at 5 per 100,000.

Burkart also pointed out, “We found a clear and statistically significant association between RSV circulation and increased hospitalization risk in the 18–59 age group, even though the absolute number of admissions remains relatively low.” She added that such hospitalizations “are concentrated among those with underlying conditions, such as chronic cardiopulmonary disease,” although the exact burden among these risk groups is unclear.

To clarify this gap, the team is undertaking a follow-up study: “We are conducting a follow-up study to compare hospitalization risks in individuals with chronic conditions, such as heart failure, COPD, or diabetes, with those in the general population.” The goal is to “better understand who is most vulnerable to severe RSV-related complications and could inform future vaccination strategies.”

Despite strong associations between RSV and cardiorespiratory events, Burkart highlighted the limitations of routine RSV testing: “RSV testing generally has a low sensitivity, and the reduced viral load in older adults, especially when tested later in the disease course, can lead to false negatives, despite the individual still experiencing adverse impacts of RSV.” She emphasized prevention given limited treatment options, “Once the patient has contracted RSV, the treatment options are limited so we underline the importance of prevention.”

US hospitalization rates remain particularly high due to demographic trends and baseline hospitalization rates. Demographic factors, “an aging population with poor underlying health and multiple comorbidities," combined with a “generally high baseline hospitalization” rate, serve to amplify RSV burden.

The study also evaluated the predictive reliability of RSV proxies, concluding that hospital-based RSV activity estimates outperformed surveillance-based proxies.

Burkart believes the data have strong policy implications, “These results provide the evidence needed to inform prevention strategies, prioritize vulnerable populations, and support international policy decisions around RSV.” She also praised the methodological advances, the study “introduces novel modeling techniques for exposure-response relationships,” and it filled data gaps in tropical and subtropical regions such as Brazil and Mexico.

This evidence supports expanded adult RSV immunization policies, improved surveillance tactics, and future cost-effectiveness research, particularly as RSV vaccines become more widely available.

Reference

Burkart K, Causey K, Biehl MH, et al. Respiratory syncytial virus-attributable hospitalizations among adults in high- and middle-income countries: application of the Global Burden of Disease framework. eClinicalMedicine. 2024;85:103292. DOI: 10.1016/j.eclinm.2025.103292