A NEW IMPROVED SUBUNIT VACCINE FOR PLAGUE - THE BASIS OF PROTECTION

In this study, we have determined the limit of protection achievable b y immunisation with sub-units of Yersinia pestis against the developme nt of plague in an experimental animal model. Co-immunisation with the purified culture-derived Fl and the recombinant V sub-units afforded a greater level of protection than with either sub-unit alone. The pro tection given by the combined sub-units was several orders of magnitud e greater than that afforded by the whole cell killed (Cutter USP) vac cine and was equivalent to that achieved by vaccination with EV76, the live attenuated Y. pestis vaccine strain. However, the combined sub-u nit vaccine has clear advantages over the live vaccine in terms of saf ety of use and absence of side-effects.