Efficacy of killed whole-parasite vaccines in the prevention of leishmaniasis : a meta-analysis

Despite decades of investigation in countries on three continents, an efficacious vaccine against Leishmania infections has not been developed. Although some indication of protection was observed in some of the controlled trials conducted with 'first-generation' whole, inactivated Leishmania parasite vaccines, convincing evidence of protection was lacking. After reviewing all previously published or unpublished randomized, controlled field efficacy clinical trials of prophylactic candidate vaccines, a meta-analysis of qualified trials was conducted to evaluate whether there was some evidence of protection revealed by considering the results of all trials together. The findings indicate that the whole-parasite vaccine candidates tested do not confer significant protection against human leishmaniasis.