Researchers have uncovered why older adults are more vulnerable to severe flu. The culprit is a protein called ApoD, which rises with age and disrupts the body’s ability to fight infection. This protein damages lung tissue and weakens immune defenses, leading to worse outcomes. By pinpointing ApoD as the driver, scientists now see a promising new treatment target that could protect elderly patients from life-threatening influenza and dramatically cut flu-related deaths.
FULL STORY
A single protein, ApoD, may explain why flu is deadlier for the elderly—and could be the key to future treatments. Credit: Shutterstock
Scientists have discovered why older people are more likely to suffer severely from the flu, and can now use their findings to address this risk.
In a new study, which is published in PNAS, experts discovered that older people produce a glycosylated protein called apoplipoprotein D (ApoD), which is involved in lipid metabolism and inflammation, at much higher levels than in younger people. This has the effect of reducing the patient's ability to resist virus infection, resulting in a more serious disease outcome.
The team established that highly elevated ApoD production with age in the lung drives extensive tissue damage during infection to reduce the protective antiviral type I interferon response.
The research was an international collaboration led by scientists from the China Agricultural University, University of Notttingham, Institute of Microbiology (Chinese Academy of Sciences), National Institute for Viral Disease Control and Prevention (Chinese Centre for Disease Control and Prevention) and the University of Edinburgh.
"Aging is a leading risk factor in influenza-related deaths. Furthermore, the global population is aging at an unprecedented rate in human history, posing major issues for healthcare and the economy. So we need to find out why older patients often suffer more severely from influenza virus infection," says Professor Kin-Chow Chang from the School of Veterinary Medicine and Science at the University of Nottingham, and co-author on the paper.
In this new study, the team investigated the mechanisms behind increased severity of influenza virus infection with age using an aging-mouse model and appropriate donor human tissue sections.
They identified ApoD as an age-related cell factor that impairs the activation of the immune system's antiviral response to influenza virus infection by causing extensive breakdown of mitochondria (mitophagy) resulting in greater production of virus and lung damage during infection. Mitochondria are essential for cellular production of energy and for induction of protective interferons.
ApoD is therefore a target for therapeutic intervention to protect against severe influenza virus infection in the elderly which would have a major impact on reducing morbidity and mortality in the aging population.
Professor Chang, added: "There is now an exciting opportunity to therapeutically ameliorate disease severity of the elderly from influenza virus infection by the inhibitory targeting of ApoD."
Story Source:
Materials provided by University of Nottingham. Note: Content may be edited for style and length.
Cite This Page:
University of Nottingham. "Why the flu turns deadly for older adults, and how scientists found the cause." ScienceDaily. ScienceDaily, 8 September 2025. <www.sciencedaily.com/releases/2025/09/250908175434.htm>.
University of Nottingham. (2025, September 8). Why the flu turns deadly for older adults, and how scientists found the cause. ScienceDaily. Retrieved September 8, 2025 from www.sciencedaily.com/releases/2025/09/250908175434.htm
University of Nottingham. "Why the flu turns deadly for older adults, and how scientists found the cause." ScienceDaily. www.sciencedaily.com/releases/2025/09/250908175434.htm (accessed September 8, 2025).
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Researchers have uncovered why older adults are more vulnerable to severe flu. The culprit is a protein called ApoD, which rises with age and disrupts the body’s ability to fight infection. This protein damages lung tissue and weakens immune defenses, leading to worse outcomes. By pinpointing ApoD as the driver, scientists now see a promising new treatment target that could protect elderly patients from life-threatening influenza and dramatically cut flu-related deaths.
FULL STORY
A single protein, ApoD, may explain why flu is deadlier for the elderly—and could be the key to future treatments. Credit: Shutterstock
Scientists have discovered why older people are more likely to suffer severely from the flu, and can now use their findings to address this risk.
In a new study, which is published in PNAS, experts discovered that older people produce a glycosylated protein called apoplipoprotein D (ApoD), which is involved in lipid metabolism and inflammation, at much higher levels than in younger people. This has the effect of reducing the patient's ability to resist virus infection, resulting in a more serious disease outcome.
The team established that highly elevated ApoD production with age in the lung drives extensive tissue damage during infection to reduce the protective antiviral type I interferon response.
The research was an international collaboration led by scientists from the China Agricultural University, University of Notttingham, Institute of Microbiology (Chinese Academy of Sciences), National Institute for Viral Disease Control and Prevention (Chinese Centre for Disease Control and Prevention) and the University of Edinburgh.
"Aging is a leading risk factor in influenza-related deaths. Furthermore, the global population is aging at an unprecedented rate in human history, posing major issues for healthcare and the economy. So we need to find out why older patients often suffer more severely from influenza virus infection," says Professor Kin-Chow Chang from the School of Veterinary Medicine and Science at the University of Nottingham, and co-author on the paper.
In this new study, the team investigated the mechanisms behind increased severity of influenza virus infection with age using an aging-mouse model and appropriate donor human tissue sections.
They identified ApoD as an age-related cell factor that impairs the activation of the immune system's antiviral response to influenza virus infection by causing extensive breakdown of mitochondria (mitophagy) resulting in greater production of virus and lung damage during infection. Mitochondria are essential for cellular production of energy and for induction of protective interferons.
ApoD is therefore a target for therapeutic intervention to protect against severe influenza virus infection in the elderly which would have a major impact on reducing morbidity and mortality in the aging population.
Professor Chang, added: "There is now an exciting opportunity to therapeutically ameliorate disease severity of the elderly from influenza virus infection by the inhibitory targeting of ApoD."
Story Source:
Materials provided by University of Nottingham. Note: Content may be edited for style and length.
Cite This Page:
University of Nottingham. "Why the flu turns deadly for older adults, and how scientists found the cause." ScienceDaily. ScienceDaily, 8 September 2025. <www.sciencedaily.com/releases/2025/09/250908175434.htm>.
University of Nottingham. (2025, September 8). Why the flu turns deadly for older adults, and how scientists found the cause. ScienceDaily. Retrieved September 8, 2025 from www.sciencedaily.com/releases/2025/09/250908175434.htm
University of Nottingham. "Why the flu turns deadly for older adults, and how scientists found the cause." ScienceDaily. www.sciencedaily.com/releases/2025/09/250908175434.htm (accessed September 8, 2025).
May 9, 2025 New research has uncovered how lipid-rich fluid in the abdomen, known as ascites, plays a central role in weakening the body's immune response in advanced ovarian cancer. The findings offer new ...
June 21, 2024 Fewer than one percent of people who get the flu every year get tested, in part because most tests require trained personnel and expensive equipment. Now researchers have developed a low-cost paper ...
Sep. 27, 2023 Lung fibrosis is a debilitating disease affecting nearly 250,000 people in the U.S. alone with 50,000 new cases reported each year. There is currently no cure and limited available treatment options, ...
May 31, 2022 A type of white blood cell previously known only as a helper in the immune system appears also to be the instigator of the body's defenses against cancerous tumors. The discovery could lead to ...
Mar. 18, 2022 An international research team has found a simple method for growing lung tissue in the lab. These organoids could be used in diagnosis, drug development, and fundamental research. Laboratory studies ...
Dec. 3, 2021 The human body's immune system weakens over time, making older adults more susceptible to infections and leaving scientists with the puzzling dilemma of how to maintain health across the ...
