Simple supplement may boost vaccine response in seniors

A daily supplement may help older adults strengthen their immune response to vaccines, according to a clinical trial. The study found that seniors who took spermidine—a compound found in foods like aged cheese and wheat germ—produced more antibodies after a COVID-19 booster shot than those who did not.

The research, conducted by immunologists at the Max Delbrück Center in Germany and the University of Oxford, involved adults aged 65 to 90 who had already received at least three COVID vaccines. Participants were divided into two groups: one received 6 mg of spermidine daily for 24 weeks, while the other took a placebo. Neither the participants nor the scientists knew who received which treatment until the trial concluded.

Blood tests showed a notable difference in participants who had previously shown little to no antibody response to vaccines. The improvement lasted even three months after they stopped the supplement. Meanwhile, those in the placebo group experienced no significant change.

“Many older adults respond well to vaccines,” said Dr. Ghada Alsaleh, an associate professor at Oxford and co-lead of the study. “But some fail to develop strong protection, even after repeated vaccination. Biological aging of immune cells may explain this.”

The trial included 40 participants. The results indicate the supplement might help rejuvenate aging immune cells by reducing markers of cellular senescence, a state where cells stop functioning properly but remain alive.

Spermidine works by enhancing autophagy, the process cells use to remove damaged components. Non-responders who took the supplement showed increased activity in genes linked to autophagy and inflammation, while markers of senescence decreased. Their B cells, responsible for producing antibodies, also became more active.

Safety was closely monitored throughout the study. Participants underwent blood tests to track kidney function, lipids, and other metabolic markers. No significant differences appeared between the two groups, and no serious side effects were reported.

The team emphasized that the findings remain preliminary. “This was a pilot trial with a limited number of participants,” said Dr. Katja Simon, the study’s other lead investigator. “Larger studies are needed to confirm whether spermidine consistently improves vaccine responses and whether similar effects occur with other vaccines, like those for seasonal influenza.”

Spermidine is available as an over-the-counter supplement, though the doses in the trial were carefully measured. The compound also occurs naturally in foods such as soybeans, mushrooms, and hard cheeses, but it remains unclear whether dietary sources provide enough to match the trial’s effects.

A phase 2 clinical trial will follow, involving more participants to test whether the supplement can enhance responses to other vaccines. If successful, spermidine could become a simple, low-cost way to improve vaccine effectiveness in older adults, a group at higher risk for infections like COVID-19 and influenza.

The results contribute to research on how cellular aging affects immunity. Earlier studies in mice had shown spermidine could boost antibody production, but this trial is among the first to suggest a similar effect in humans. The team also identified biomarkers that might help doctors predict which patients are less likely to benefit from vaccines without additional support.

The study appeared in Aging Cell and received funding from the European Research Council and the UK’s Medical Research Council. The trial was preregistered on ClinicalTrials.gov to ensure transparency.

While the findings are encouraging, experts caution against recommending spermidine as a routine supplement for vaccine support. Further research is needed to confirm the results and determine the best dosage. For now, older adults should continue following recommended vaccine schedules and consult healthcare providers with any concerns.

Some companies have already begun exploring how healthcare firms cut help desk costs through automation, but supplements like spermidine could offer a different kind of support for immune health.