A recent study published in the eLife journal examined how they can improve older adults' responses to vaccines. The lead author Ghada Alsaleh, a postdoctoral researcher at the Kennedy Institute of Rheumatology, University of Oxford, UK, explained how older adults are at high risk of getting infected with infectious diseases, and that vaccines in this age group are less efficient than in younger people.
The researchers examined mice immune cells of different ages. They found out that old mice immune cells are less efficient in a natural process called autophagy, which is like a cleaning process where the cells remove debris and unnecessary cellular components. Autophagy affects immunity.
They wanted to examine if the same thing happens in human immune cells, particularly T cells by examining samples of young and older people participating in some vaccine clinical trials like the hepatitis C virus vaccine.
By examining the T cells, they found that autophagy increased in young people in response to vaccines, but didn't occur in older people. By looking closely at the cells, they found out that T cells of older people have less of a natural component called spermidine. Spermidine is a naturally occurring polyamine that induces autophagy to maintain homeostasis in cells.
The research team supplemented the T cells of older people with spermidine in the lab to check if autophagy will be restored to the same levels as the T cells of younger people, and it did. They suggest that increasing autophagy in older people during vaccination may help increase its efficacy; they are looking into doing this with spermidine supplementation.
"Our findings will inform vaccine trials in which autophagy-boosting agents, such as spermidine, are given in a controlled environment to older participants," concludes senior author Anna Katharina Simon, Professor of Immunology at the University of Oxford. "It will be interesting to see whether these agents can enhance vaccination efficiency and help protect older people from viral infections."
Their suggestion is based on another trial where spermidine was given to older people to see if it will improve their cognitive functions, and it did with no harmful effects.
To learn more about the autophagy process, watch the video below.