Calcitriol (1,25-dihydroxy-vitamin D3) coadministered with influenza vaccine does not enhance humoral immunity in human volunteers

Calcitriol, also known as 1,25-dihyrody-vitamin D3, is a steroid hormone th at has been shown to have effects on cytokine production and lymphocyte pro liferation. Coadministration of calcitriol with trivalent influenza vaccine in mice enhanced both mucosal and sytemic antibody responses. We studied t he effects of calcitriol coadministered with a commercially available influ enza vaccine: in 175 human volunteers in this double-blind, placebo control led clinical trial. Subjects that received calcitriol experienced more pain at the injection site compared with placebo recipients. No significant dif ferences in hemagglutination inhibition titers against MINI, H3N2, or influ enza B antigens were detected at 1 or 3 months postvaccination. We conclude that coadministration of 1.0 mu g of calcitriol at a site adjacent to infl uenza vaccination does not enhance humoral immunity in human volunteers (C) 1999 Elsevier Science Ltd. All rights reserved.