RSV is very common in adults, though most cases are mild enough that people never realize they have it. Nearly all adults have been infected with RSV multiple times by middle age, since the virus does not produce lasting immunity. In the U.S. alone, RSV causes an estimated 60,000 to 160,000 hospitalizations and 6,000 to 10,000 deaths among adults 65 and older each year. For healthy younger adults, RSV typically looks and feels like any other cold. For older adults and those with chronic health conditions, it can be serious.
How Often Adults Get RSV
RSV circulates every year, primarily during fall and winter, and reinfects people throughout their lives. Unlike measles or chickenpox, a previous RSV infection offers only partial, temporary protection. Most healthy adults catch RSV every few years without ever getting tested for it, because the symptoms are indistinguishable from a standard cold: runny nose, cough, sore throat, mild headache, and fatigue.
Hospitalization rates tell the more serious side of the story. Among U.S. adults aged 18 to 49, roughly 21 per 100,000 are hospitalized for RSV-related respiratory illness each year. That number climbs sharply with age. A pooled analysis of multiple studies found approximately 178 hospitalizations per 100,000 U.S. adults aged 65 and older annually. When researchers adjusted for the fact that many cases go undetected by standard testing, the estimate rose to 267 per 100,000.
Why RSV Is Underdiagnosed in Adults
A major reason RSV flies under the radar in adults is that doctors rarely test for it. When a middle-aged person shows up with a cough and congestion, clinicians typically treat it as a generic upper respiratory infection. Even when testing does happen, the results can miss infections. Rapid antigen tests, the quickest option, catch only about 64% of adult RSV cases compared to the gold-standard PCR test. Adults tend to carry lower amounts of the virus in their nasal passages than children do, making detection harder.
Testing from multiple sites helps. Adding a sputum sample to a standard nasal swab PCR test increased detection by 52% in one analysis. Adding a throat swab boosted it by 28%. The practical takeaway: the true number of adult RSV infections is substantially higher than what surveillance systems report.
Who Faces the Greatest Risk
Age is the single biggest risk factor. Adults 65 and older account for the vast majority of RSV hospitalizations and deaths. But age alone doesn’t tell the whole story. Chronic lung disease, heart conditions, diabetes with organ damage, weakened immune systems, and severe obesity (BMI of 40 or higher) all increase the odds of a severe outcome at any age above 50.
The numbers for people with existing lung conditions are striking. Adults with COPD who catch RSV are hospitalized at roughly 10 times the rate of adults without the condition. More than 83% of hospitalized COPD patients with RSV experienced a flare-up of their lung disease, and in-hospital death rates ranged from 2.8% to 17.8%. For adults with asthma, hospitalization rates were 7 to 8 times higher than average, with up to 64.9% experiencing an asthma exacerbation triggered by the virus.
RSV Compared to the Flu
Adults often wonder whether RSV is “as bad as the flu.” A seven-season study of patients aged 75 and older at a French hospital found that 30-day mortality rates were virtually identical: 9.6% for RSV versus 9.7% for influenza. But RSV patients fared worse in other ways. They were more likely to develop pneumonia with lung consolidation, more likely to need intensive care, and stayed in the hospital longer on average. RSV’s reputation as a “children’s virus” has led to less public awareness and less routine testing, which means many adult cases simply get labeled as flu or a bad cold.
Long-Term Effects After Severe RSV
For older adults who are hospitalized with RSV, the consequences can extend well beyond the acute illness. A meta-analysis looking at outcomes 90 days or more after hospitalization found that 17% to 25% of patients experienced a measurable decline in their ability to perform daily activities, things like bathing, dressing, cooking, or managing medications. This functional decline likely results from a combination of prolonged bed rest, post-viral fatigue, and the toll of underlying health problems.
Cardiovascular complications appeared in 13% to 20% of hospitalized patients over the long term, including heart rhythm disturbances, worsening heart failure, and heart attacks. Persistent lung symptoms like shortness of breath and abnormal chest imaging showed up in 26% to 38% of patients, though the statistical link to RSV specifically (as opposed to the patients’ pre-existing conditions) was weaker. The overall picture is that a serious RSV hospitalization can be a turning point for an older adult’s independence and cardiovascular health.
How RSV Spreads Between Adults
RSV spreads through respiratory droplets when an infected person coughs or sneezes, and through direct contact with contaminated surfaces. The virus can survive on hard surfaces like doorknobs and countertops for several hours. You’re typically contagious for 3 to 8 days, starting a day or two before symptoms appear. People with weakened immune systems can shed the virus for four weeks or longer, even after feeling better.
Vaccines Now Available for Adults
Three RSV vaccines are currently licensed for adults in the U.S.: Arexvy (GSK), Abrysvo (Pfizer), and mResvia (Moderna). The CDC recommends a single dose for all adults 75 and older, and for adults 50 to 74 who have conditions that raise their risk of severe RSV. That includes chronic heart or lung disease, diabetes with organ complications, kidney failure, liver disease, severe obesity, moderate to severe immune compromise, and residence in a nursing home.
You don’t need medical records to prove you qualify. The CDC’s guidance states that your own report of having a risk factor is sufficient. Only one dose is currently recommended, not an annual shot like the flu vaccine.