title: Progress and challenges associated with the development of ricin toxin subunit vaccines.
abstract: The past several years have seen major advances in the development of a safe and efficacious ricin toxin vaccine, including the completion of two Phase I clinical trials with two different recombinant A subunit (RTA)-based vaccines: RiVax™ and RVEc™ adsorbed to aluminum salt adjuvant, as well as a non-human primate study demonstrating that parenteral immunization with RiVax elicits a serum antibody response that was sufficient to protect against a lethal dose aerosolized ricin exposure. One of the major obstacles moving forward is assessing vaccine efficacy in humans, when neither ricin-specific serum IgG endpoint titers nor toxin-neutralizing antibody levels are accepted as definitive predictors of protective immunity. In this review we summarize ongoing efforts to leverage recent advances in our understanding of RTA-antibody interactions at the structural level to develop novel assays to predict vaccine efficacy in humans.
authors.affiliation: a Division of Infectious Disease, Wadsworth Center, New York State Department of Health , Albany , NY , USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Vance
authors.affiliation: a Division of Infectious Disease, Wadsworth Center, New York State Department of Health , Albany , NY , USA.|b Department of Biomedical Sciences , University at Albany , Albany , NY , USA.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Mantis
mesh_terms: D000818:Animals; D002619:Chemical Warfare Agents / Q000633:toxicity*; D017321:Clinical Trials, Phase I as Topic; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D006801:Humans; D011041:Poisoning / Q000517:prevention & control*; D012276:Ricin / Q000633:toxicity*; D022223:Vaccines, Subunit / Q000276:immunology* / Q000302:isolation & purification*
chemical_list: D002619:Chemical Warfare Agents; D022223:Vaccines, Subunit; D012276:Ricin
keywords: Toxin; antibody; biodefense; epitope; neutralizing; protection; vaccine