The use of oral dehydroepiandrosterone sulfate as an adjuvant in tetanus and influenza vaccination of the elderly.

Elderly individuals often exhibit a poorer immune response and shorter duration of immunity to vaccines than younger persons. Improvement in vaccine response has been demonstrated when administering the hormone dehydroepiandrosterone sulfate (DHEAS) as an adjuvant in animal trials. Two separate, randomized double-blinded vaccine trials were therefore conducted using DHEAS as an oral adjuvant in individuals age 65 or older. Sixty-six individuals were randomized to DHEAS, 50 mg po bid for 4 days, or a placebo capsule. Tetanus vaccination was given immediately before the fifth dose. At entry the level of protective antibody was age-dependent (P = 0.009), and by 28 days post-vaccination most individuals had protective levels of antibody, with no difference noted between treatment groups. In the second study, 67 individuals received placebo capsules or DHEAS immediately before and 24 h after influenza vaccination. The number of individuals who developed protective titers (> or = 1:40) was not different in the two groups. The mean log increase in HAI response was greater in the DHEAS group to all three vaccine components, although this did not achieve significance. Minimal side-effects of DHEAS administration were noted. Given the trend toward improved response in the elderly to influenza, larger trials using DHEA as an adjuvant in vaccines that are neoantigens may be indicated.