A naturally occurring compound called spermidine may help boost vaccine responses in some older adults by reducing the biological signs of aging in the immune system, according to research published in 2016. aged cells.
As we age, our immune systems become less efficient, making it harder for our bodies to fight infections and respond fully to vaccines. This gradual decline, known as immunosenescence, increases vulnerability to age-related health problems and may leave some older people less protected after vaccination.
Spermidine may support aging immunity
The research was led by Dr Katya Simon, Group Leader in the Immune Cell Biology Laboratory at the Max Delbrück Center, and Dr Ghada Alsaleh, Associate Professor in the Nuffield School of Orthopedics, Rheumatology and Musculoskeletal Sciences (NDORMS) at the University of Oxford.
Their findings suggest that daily spermidine supplementation improved several measures of immune response after COVID-19 vaccination.
Spermidine is naturally produced by human cells and is also found in foods such as wheat germ, mushrooms, Parmesan cheese, and cheddar cheese. Previous studies have shown that this molecule may support cell maintenance mechanisms whose activity decreases with age.
“Many older people respond well to vaccines,” Alsale explained. “However, some people do not develop strong protection despite repeated vaccinations. Biological aging of immune cells may be one reason why this occurs. Our findings suggest that spermidine may help restore aspects of immune function in this group.”
The project also involved researchers from the Oxford Vaccine Group. Paul Klenerman, Teresa Lambe, Lucy Jones, and Owen B. Spiller of Cardiff University.
Why vaccines become less effective with age
The novel coronavirus disease (COVID-19) pandemic has reminded us of the importance of vaccination in preventing severe illness and death. However, older people often produce fewer protective antibodies and T cells after vaccination. A similar pattern has been observed with influenza vaccination.
To investigate whether spermidine could ameliorate this response, Simon and colleagues enrolled 40 healthy adults aged 65 and older. After receiving the third COVID-19 vaccine, participants took 6 milligrams of spermidine or a placebo daily for 13 weeks.
About a quarter of the participants had very weak antibody responses even after receiving three doses of the vaccine. Their immune cells also showed clear signs of biological aging, including greater DNA damage and molecular markers associated with cellular senescence. During cellular senescence, damaged or aged cells no longer function properly, but remain in the body and accumulate over time.
Antibody responses were stronger in some participants
Vaccine non-responders who received spermidine had significant improvements in several indicators of vaccine-related immunity. These participants generally developed higher levels of antibodies against SARS-CoV-2 and showed stronger neutralizing activity against some virus variants.
Researchers also found that spermidine lowered markers associated with immunosenescence and increased autophagy. Autophagy is a natural recycling process that allows cells to remove damaged materials and maintain normal function.
This supplement appears to be safe and well-tolerated. The researchers found no adverse effects associated with the treatment.
Larger trials still needed
Because the study included just 40 participants, the researchers cautioned that the results should be seen as early evidence rather than definitive proof that spermidine can improve vaccination outcomes.
“This study was designed as a pilot study and involved a relatively small number of participants,” Simon says. “Larger studies will be needed to determine whether spermidine can consistently improve vaccine responses and whether similar effects are seen with other vaccines, such as those used against seasonal influenza.”
