RSV-ARI nearly triples mortality risk in new study

Acute respiratory infection caused by respiratory syncytial virus (RSV-ARI) nearly triples the risk of death, particularly among individuals with chronic underlying respiratory conditions, as shown in a nationwide cohort study in Denmark.

“Exacerbations of chronic obstructive pulmonary disease (COPD) and asthma were the most common adverse clinical outcomes,” reported lead author Maria João Fonseca, PhD, associate director of Global Real-World Evidence and Health Outcomes, Vaccines at GSK, at ESCMID Global 2025. “These pre-existing conditions are already challenging in themselves, and RSV-ARI exacerbated their severity.”

The study involved 5,289 adults diagnosed with RSV-ARI between 2011 and 2022, matched against 15,867 controls from the general population. Participants had a mean age of 63 years, and 57 percent were female. Thirty-two percent of individuals were immunocompromised.

Participants were followed for 1 year, with analyses focusing on clinical outcomes, including hospitalization, disease exacerbation, and economic impact. A significant proportion of patients with COPD and asthma were included, allowing for subgroup evaluation of these at-risk groups.

At 1 year of follow-up, mortality risk was 2.7 times higher in adults with RSV-ARI, exceeding that of the general population (13 percent vs 4.8 percent; p<0.001). In addition to the increased risk of death, these individuals had significantly poorer health outcomes than the controls, with COPD occurring 3.1 times more frequently (55.78 percent vs 18.3 percent; p<0.001) and asthma exacerbations occurring 4.6 times more often (24.1 percent vs 5.2 percent; p<0.001). [ESCMID Global 2025, abstract 03800]

One striking finding from the study was the prolonged and significant impact of RSV-ARI. “Even after the acute phase, patients continued to experience worse outcomes than the general population. This underscores just how serious and enduring the effects of RSV-ARI can be,” said Fonseca.

“Thus, it is important that we pay closer attention to these patients, particularly those with underlying conditions, to prevent further, potentially life-threatening complications,” she added.

Hospitalization rates and intensive care admissions

Additionally, hospitalization rates were 57 percent among patients with RSV-ARI compared with 28 percent in the control group, while intensive care admissions were nearly quadrupled (5.3 percent vs 1.4 percent).

The financial burden was also significant, with RSV-ARI patients incurring average direct healthcare costs of EUR 20,181 (USD 22,986) over 1 year, which is more than double the EUR 8,085 (USD 9,221) spent on the controls.

RSV is a common and highly contagious virus primarily affecting the respiratory tract. Although its impact on children and infants has been widely studied, the extent of its burden on adults remains poorly understood.

“Our study highlights the significant, yet often underrecognized, long-term health and economic burden of RSV-ARI in adults, particularly among patients with COPD and asthma,” said Fonseca.

Vaccination prevents severe outcomes

Commenting on the study, co-author Dr Stanislava Bratković, Medical Advisor for Vaccines at GSK, said vaccination has been shown to be effective in preventing severe outcomes from RSV. “Given the significant burden of RSV-ARI highlighted by our study, prioritizing vaccination for vulnerable populations is essential to reduce both health complications and the associated costs.”

She was optimistic that the findings would encourage further studies on the clinical and societal burden of RSV, particularly in high-risk groups. “This will help shape more targeted preventive strategies and ensure timely interventions for patients who need it most.”