Editing Ricin (section)

== Vaccination ==

[[File:RTAvaccines.jpg|thumb|400px| Ricin toxin, RiVax, RTA1-33/44-198, and a single domain antibody-antigen complex with the RTA1-33/44-198 immunogen. Original figure can be found in Legler, et al.<ref name="pmid27660893">{{cite journal | vauthors = Legler PM, Compton JR, Hale ML, Anderson GP, Olson MA, Millard CB, Goldman ER | title = Stability of isolated antibody-antigen complexes as a predictive tool for selecting toxin neutralizing antibodies | journal = mAbs | volume = 9 | issue = 1 | pages = 43–57 | date = January 2017 | pmid = 27660893 | pmc = 5240650 | doi = 10.1080/19420862.2016.1236882 }}</ref><ref name="Legler_2011">{{cite journal | vauthors = Legler PM, Brey RN, Smallshaw JE, Vitetta ES, Millard CB | title = Structure of RiVax: a recombinant ricin vaccine | journal = Acta Crystallographica. Section D, Biological Crystallography | volume = 67 | issue = Pt 9 | pages = 826–830 | date = September 2011 | pmid = 21904036 | pmc = 3169317 | doi = 10.1107/S0907444911026771 | bibcode = 2011AcCrD..67..826L }}</ref>]] 

Ricin toxin vaccines have emerged as a focus in [[biodefense]] research. Two recombinant A subunit (RTA)-based vaccines, RiVax and RVEc (also known as RTA1-33/44-198),<ref name="pmid15187223">{{cite journal | vauthors = Olson MA, Carra JH, Roxas-Duncan V, Wannemacher RW, Smith LA, Millard CB | title = Finding a new vaccine in the ricin protein fold | journal = Protein Engineering, Design & Selection | volume = 17 | issue = 4 | pages = 391–397 | date = April 2004 | pmid = 15187223 | doi = 10.1093/protein/gzh043 }}</ref><ref name="pmid23364220">{{cite journal | vauthors = Janosi L, Compton JR, Legler PM, Steele KE, Davis JM, Matyas GR, Millard CB | title = Disruption of the putative vascular leak peptide sequence in the stabilized ricin vaccine candidate RTA1-33/44-198 | journal = Toxins | volume = 5 | issue = 2 | pages = 224–248 | date = January 2013 | pmid = 23364220 | pmc = 3640533 | doi = 10.3390/toxins5020224 | doi-access = free }}</ref> have completed Phase I clinical trials, and were found to be safe.<ref name="Vance_2016">{{cite journal | vauthors = Vance DJ, Mantis NJ | title = Progress and challenges associated with the development of ricin toxin subunit vaccines | journal = Expert Review of Vaccines | volume = 15 | issue = 9 | pages = 1213–1222 | date = September 2016 | pmid = 26998662 | pmc = 5193006 | doi = 10.1586/14760584.2016.1168701 }}</ref> These vaccines are based on modified versions of the ricin toxin A-chain, designed to reduce toxicity while maintaining [[immunogenicity]].