Respiratory infections
- Influenza, COVID-19, RSV and pneumonia
- Higher risk of severe disease, hospitalization and death
- Vaccination is key
Infections
and Aging
Greater Risks. Stronger Prevention.
As we age, our immune system changes, making it harder to detect, control and eliminate infections. Understanding how aging affects your immune defenses can help you make informed choices to reduce your risk and stay healthier, longer.
Explore the science →Why Infections Are a Greater Risk With Age
A combination of immune, biological and social factors.
Higher risk of infection
Older adults are more likely to get infected and to develop severe disease.
Greater complications
Infections can lead to hospitalization, long-term disability and increased mortality.
More than immune changes
Chronic conditions, frailty, environment and other factors also increase vulnerability.
The Impact of Infections in Older Adults
Infections are a major cause of illness, hospitalization and death.
Higher risk
Higher risk of hospitalization for respiratory infections
Infections
are among the leading causes of hospitalization in adults ≥65
Greater burden
Older adults are disproportionately affected by severe infectious disease
Higher risk
of severe disease for influenza, COVID-19 and pneumococcal infections
What Makes Older Adults More Vulnerable?
- Changes in immune-cell function
- Reduced naïve T- and B-cell repertoires
- Altered inflammatory responses (inflammaging)
- More chronic health conditions
- Higher likelihood of functional decline
- Increased exposure in healthcare settings
- Atypical symptoms can delay diagnosis
How the Immune System Changes With Age
Immunosenescence and inflammaging affect both innate and adaptive immunity.
Innate immune cells
Reduced pathogen detection and signaling
Dendritic cells
Altered antigen presentation and activation of T cells
T cells
Fewer naïve T cells, altered function and reduced repertoire diversity
B cells
Decreased antibody responses and less durable immunity
Chronic inflammation
Persistent low-grade inflammation can impair effective immune responses
Immunosenescence + Inflammaging
Two interconnected features of immune aging.
IMMUNOSENESCENCE
Changes in immune-cell composition and function, including reduced naïve T and B cells, altered innate responses and impaired immune regulation.
INFLAMMAGING
Chronic, low-grade inflammation characterized by a persistent elevation of inflammatory mediators and linked to metabolic changes, cellular senescence and chronic infections.
Result: higher risk and more severe infections
Common Infections in Older Adults
Some infections are more common or more severe with age.
Urinary tract infections
- Very common in older adults
- Can lead to hospitalization and sepsis
- Atypical symptoms are frequent
Skin and soft tissue infections
- Higher risk due to changes in skin barriers and comorbidities
- Can lead to serious complications
Gastrointestinal infections
- Norovirus, Clostridioides difficile and foodborne pathogens
- Higher risk of dehydration, hospitalization and recurrence
Bloodstream infections (sepsis)
- Increased risk and severity, especially in older adults
- Often associated with other infections
- High mortality risk
Infections and Chronic Health Conditions
Conditions such as cardiovascular disease, diabetes, chronic lung disease, kidney disease and frailty can increase susceptibility to infections and the risk of severe outcomes.
Recognizing Infections in Older Adults
Symptoms can be different and sometimes less obvious:
Potential Consequences
Infections can have lasting effects.
Prevention Strategies
Multiple approaches help reduce the risk of infection.
Vaccination in Older Adults
Vaccines are a key tool to prevent serious infections.
Influenza
Annual vaccination reduces the risk of severe disease and hospitalization
COVID-19
Vaccination lowers the risk of severe disease, hospitalization and death
RSV
U.S. CDC guidance: recommended for all adults ≥75 and adults 50–74 at increased risk of severe RSV illness. Check current local guidance.
Pneumococcal disease
Vaccination helps prevent serious pneumonia and bloodstream infection
Shingles (herpes zoster)
Recommended for adults ≥50 to prevent shingles and complications
Healthy Aging Includes Infection Prevention
While we cannot eliminate all risks, many serious infections are preventable. Vaccination, healthy lifestyle choices and good medical care can help you stay healthier, more independent and enjoy the years ahead.
Take care of your ImmAge. →Selected sources and references
- Nikolich-Žugich, 2018 — The twilight of immunity: emerging concepts in aging of the immune system
- CDC — Flu and people 65 years and older
- Infections in the elderly, 2007
- Immunosenescence and human vaccine immune responses, 2019
- CDC — RSV vaccines for adults (U.S. eligibility guidance)
Artwork illustrates the main mechanisms schematically; molecular sizes, colors and distances are not literal.