Multivariable linear regression indicated that patients with arthritis had lower CD8 T cell responses than the healthy control group (frequency of responding CD8 after three vaccine doses 0.002% (0.0001–0.016), regression coefficient 0.11 (95% CI 0.02–0.53), p = 0.0072) (Fig. 3c). This evidence concerns the gene CD8A and arthritic joint disease.