Two recent studies published this week assess the low uptake of respiratory syncytial virus (RSV) vaccine among US veterans and examine the risk factors for intensive care unit (ICU) admission and death among older patients hospitalized with RSV, influenza, or human metapneumovirus (HMPV) in a cohort of Colorado residents.
In the first study, published in Open Forum Infectious Diseases, authors looked at RSV vaccine uptake in 2023-2024 and 2024-2025 among eligible US veterans. Eligible veterans included all those with at least one primary care visit between 2020 and 2021 and were ages 60 years and older by September 1, 2023.
Those veterans were able to get one of two approved RSV vaccines free of cost beginning in the 2023-24 RSV season.
Of the 3,497,851 vaccine-eligible veterans, only 342,818 (9.8%) received an RSV vaccine during the 2023-24 season. Among 3,155,033 unvaccinated veterans from that season, 2,757,249 were eligible for vaccination in 2024-25, with 82,237 (3.0%) receiving the vaccine during the first four months of the 2024-2025 season.
In-person visits linked to more vaccine uptake
In both seasons, in-person visits yielded more uptake than virtual visits, with 1.3% of veterans who had virtual visits receiving the vaccine in 2024-25 compared to 3.0% who had in-clinic appointments.
Uptake was lowest among veterans who lived in rural areas, were ages 60 to 74 years, and were current smokers. Housing insecurity was also linked to a lower likelihood of receiving the vaccine.
Among individuals with social risk factors, vaccine uptake remained lower, underscoring the need for targeted strategies.
“Among individuals with social risk factors, vaccine uptake remained lower, underscoring the need for targeted strategies,” the authors concluded.
Dementia linked to RSV mortality
In the second study, published in the Journal of Infectious Diseases, risks of ICU admission and mortality were assessed among Colorado residents who were 50 years or older between 2016 and 2023, who had RSV, influenza, or HMPV pneumonia hospitalizations. Outcomes were compared to those admitted with other ARI (acute respiratory illness) caused by these viruses, but not pneumonia.
Overall, among 2,210 hospitalized patients with RSV pneumonia, 780 (35%) were admitted to the ICU and 205 (9.3%) died. For influenza pneumonia these figures were 7,174, 2,332 (32.5%) and 545 (7.6%) and HMPV pneumonia 1,482, 408 (27.5%) and 88 (5.9%) respectively, the authors said.
Among adults with RSV pneumonia, dementia had the highest odds for ICU admission (adjusted odds ratio, 4.2). Increasing age was associated with increasing rates of mortality for RSV and influenza pneumonia.
Obesity, diabetes, and chronic renal disease were not linked to increasing ICU admission or mortality rates.
