Bringing adult RSV research to the forefront: the impact of health conditions and socioeconomic status on RSV hospitalization
January 23/2026
CVPD experts’ latest research highlights the connection between the severity of RSV hospitalization for older adults with pre-existing health conditions.
By Aislinn DeRoches
As the temperature continues to drop, we are often reminded to receive our fall and winter vaccinations. While people may initially think of influenza (flu) and COVID-19 when thinking of seasonal vaccines, Respiratory Syncytial Virus (RSV) is another important vaccine for those eligible to receive one.
In Ontario, RSV season starts as early as November and can last until April. Due to the risks associated with RSV, especially for those with underlying health conditions, older adults are encouraged to receive their RSV vaccine.
“I think we are beginning to understand a lot more about the potential consequences of RSV infection, which can be very serious for high-risk populations,” says Sarah Buchan, associate professor at the Dalla Lana School of Public Health (DLSPH) and member of the Centre for Vaccine Preventable Diseases (CVPD). “For this reason, Canada’s National Advisory Committee on Immunization (NACI) currently recommends that everyone aged 75 years or older should receive an RSV vaccine, particularly for those at increased risk of severe RSV disease, along with those 60 and over who are residents of long-term care homes or other chronic care facilities.”
Research on the increased burden of RSV on adults
Often, RSV research focuses on the impact on infants and children, while the significant impact of RSV on older adults and adults with pre-existing medical conditions has remained in the background.
A recent study led by Sarah Buchan, Incidence of Respiratory Syncytial Virus-Associated Hospitalization Among Adults in Ontario, Canada, 2017–2019, aimed to bring the significant burden that RSV has on older adults and those with pre-existing medical conditions to the forefront.
This study found that over two respiratory virus seasons in Ontario, there were 3,928 hospitalizations associated with RSV in adults aged 18 and over. Of those hospitalized, 96.1% had at least one pre-existing health condition, with chronic kidney disease, diabetes, asthma, and chronic obstructive pulmonary disease being the most common.
“We have known for a long time that RSV is a very significant infection for infants, causing substantial burden on the health care system each year; however, the importance of RSV in adults was not at the forefront,” says Buchan. “The impetus for doing this study was to help inform vaccine recommendations, since several products for adults were coming to market.”
Pre-existing health conditions and socioeconomic status can result in a higher risk of hospitalization for RSV
With the goal of gathering evidence that could help inform decision making around RSV vaccines and eligibility, Buchan and her team aimed to examine a wide variety of medical conditions, to understand who is most at risk for severe RSV.
“Vaccine recommendations have typically been driven by age, but I think our results really demonstrate that the role of medical conditions, particularly among younger adults, is of critical importance,” says Buchan. “We see some younger adults with medical conditions who are actually at higher risk for hospitalization due to RSV than healthy older adults, and that risk increases with the number of conditions.”
Another factor that Buchan and her team considered in their study was socioeconomic status.
“I think the social determinants of health have been under-appreciated when it comes to the burden of respiratory viruses, although the COVID-19 pandemic helped to shine a light on these inequities,” she says.
The study found a significant burden of RSV among those of low socioeconomic status, with hospitalizations for RSV nearly doubling for those residing in the lowest-income neighbourhoods compared to those living in higher-income neighbourhoods.
“We know that socioeconomic status influences other risk factors for severe RSV disease, such as access to resources, environmental exposures (crowding, pollution) and health-promoting behaviours,” explains Sarah. “Having this data may be a helpful framework for identifying populations that would benefit from RSV prevention, whether through immunization or other efforts.”
The importance of the RSV vaccine
According to a national vaccination survey done by the Canadian Pharmacists Association (CPhA), just over 50% of Canadians are currently experiencing moderate to high levels of vaccine fatigue and thus could be less likely to receive their seasonal vaccinations.
While this same survey shows that more than half of Canadians aged 60 and older would receive an RSV vaccine if available to them, 30% of those who said they would not receive an RSV vaccine held the belief that they did they did not think they needed one.
While symptoms can be mild, contracting RSV can often lead to other complications.
“As with other respiratory viruses such as influenza and SARS-CoV-2, RSV most often causes cold-like symptoms like runny nose, cough, sore throat, headache, and fever,” explains Jeff Kwong, CVPD’s associate director and professor at DLSPH. “However, for some people, RSV infections can be more serious, with wheezing, shortness of breath, chest pain, or severe fatigue, and may result in pneumonia or worsening of underlying chronic conditions such as asthma, heart failure, and kidney failure that can lead to hospitalization or even death.”
In addition to the immediate effects of RSV, Buchan believes communicating the problems that come after having RSV, otherwise known as downstream effects, is “really important” when discussing immunization.
“We know that RSV (and other respiratory viruses) are associated with cardiac events such as myocardial infarction (i.e., heart attack) and with secondary bacterial infections,” she says. “We also have data, including from our study, demonstrating that a high proportion of community-dwelling older adults who are hospitalized for RSV are discharged from hospital with a higher level of care needs. So, with immunization, we can also mitigate some of these downstream effects.”