A common arthritis medication given briefly before flu vaccination significantly enhanced antibody responses in older adults, according to a study published in Nature Aging.
Researchers at Yale University tested whether tofacitinib, a JAK inhibitor used to treat rheumatoid arthritis, could improve vaccine effectiveness in people aged 65 and older. This population typically shows weaker responses to vaccination due to age-related changes in the immune system, a phenomenon known as immunosenescence.
The trial enrolled 150 adults aged 65 years and older, randomly assigning them to receive placebo, five days of tofacitinib, or ten days of tofacitinib before receiving a standard flu vaccine. Both tofacitinib groups showed significantly higher antibody responses compared with the placebo group. These elevated antibody levels persisted at three months and remained detectable at six months after vaccination.
The researchers hypothesised that temporarily reducing background inflammation before vaccination allows the immune system to mount a more focused response to the vaccine antigens. Lead author Dr Erin Xu noted that chronic low-grade inflammation in older adults may impair their ability to respond effectively to vaccines.
This “immune preconditioning” approach could offer practical advantages over other strategies for improving vaccine responses in older populations. Unlike adjuvants, which require reformulating vaccines, using an existing approved medication could be implemented with current vaccine formulations.
The findings suggest potential applications beyond influenza vaccination, including COVID-19 and other vaccines where older adults show reduced responses. However, further research is needed to confirm safety and efficacy across different vaccine types and patient populations before clinical implementation.
Source: Medical Xpress / Yale University (Nature Aging, 2026)
