Techniques from two basic approaches, structure-based immunogen design and phage T4 nanoparticle delivery, are developed to construct new plague vaccines. The NH2-terminal β-strand of F1 of Yersinia pestis is transplanted to the COOH-terminus of F1 of Yersinia pestis and the NH2-terminus sequence flanking the β-strand of F1 of Yersinia pestis is duplicated to eliminate polymerization but to retain the T cell epitopes. The mutated F1 is fused to the V antigen of Yersinia pestis to thereby form a fusion protein F1mut-V mutant, which produces a completely soluble monomer. The fusion protein F1mut-V is then arrayed on phage T4 nanoparticles via a small outer capsid protein, Soc, from a T4 phage or a T4-related phage. Both the soluble and T4 decorated F1mut-V provided approximately 100% protection to mice and rats against pneumonic plague evoked by high doses of Yersinia pestis CO92.