There is no demographic more at risk for succumbing to the negative effects of the flu than the elderly population. A new study of the influenza virus from researchers at Yale School of Medicine helps to illustrate this point, finding that aging impairs the immune system’s response to the flu virus in more ways than one.
“Influenza virus mortality is the highest in older adults. This study sheds light on a mechanism that underlies this impaired antiviral response,” said senior author Akiko Iwasaki, the Waldemar Von Zedtwitz Professor of Immunobiology and Howard Hughes Medical Institute investigator at Yale School of Medicine.
A serious viral infection
The flu can be a devastating infection and sometimes deadly when affecting particular demographics. It is characterized by fever, cough, and body aches, with older adults, young children, pregnant women, and those with chronic health problems at higher risk of serious complications.
It is estimated that between 5 to 20 percent of the U.S. population will get the flu every year. Worldwide, influenza is estimated to kill roughly 250,000 to 500,000 annually, according to the World Health Organization.
The study in question led researchers to collect blood samples from healthy young adults and older adults aged 65 and above. Their goal was to investigate the innate or inborn immune response that the body had the flu virus. White blood cells involved in fighting off infections were isolated from each blood sample and stimulated with the flu virus to see they would react.
If was found that the white blood cells from older adults were severely impaired when fighting off the flu virus, as they were unable to release interferons – potent antiviral proteins. It is believed that age-related damage to the white blood cells from the older group of participants makes signaling for the release of interferon difficult.
Reduced immune response in the elderly
The researchers believe that without this signaling process, along with other involved antiviral genes, resistance to the flu falls short.
“In older adults, we might have to use a different strategy to treat and immunize against flu. We need to find a way to boost the antiviral defense that does not rely on interferon production. For vaccines, we need to find an adjuvant – a component added to a vaccine – that would still stimulate the innate immune response in older adults,” said Iwasaki.
This study provides new insight into the flu and how it affects older adults. It also brings to attention the importance of finding new strategies for reducing flu-related complications in this older age group.
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