ABSTRACT
BACKGROUND: Attenuated Listeria monocytogenes vaccine strains have been administered intravenously (Le et al., Maciag et al.) and orally (Angelakopoulos et al., Johnson et al.) to humans. Here, one was given transcutaneously with cholera toxin adjuvant. METHODS: Eight healthy volunteers were studied (5 active, 3 placebo). Safety was assessed by physical exam and labs. Systemic immunological responses were measured by ELISA and IFN-gamma ELISpot. RESULTS: 4/5 active volunteers had cellular responses to listerial antigens. 5/5 active volunteers showed humoral responses to cholera toxin. CONCLUSIONS: An attenuated L. monocytogenes vector was safely administered transcutaneously. Topical administration appeared at least as immunogenic as previously studied oral delivery.
