A single dose sub-unit vaccine protects against pneumonic plague

LcrV Delivered via Type III Secretion System of Live Attenuated Yersinia pseudotuberculosis Enhances Immunogenicity against Pneumonic Plague

“…Studies demonstrated that Chinese-origin rhesus macaques immunized with EV76 or mice immunized with the Y. pestis ⌬smpB-ssrA mutant primed a higher anti-F1 IgG titer but an almost undetectable titer with respect to LcrV antigen (38,50), results that are consistent with other studies of animals immunized with the EV76 or KWC vaccine (51)(52)(53)(54)(55)(56)(57). Mice vaccinated with Y. pestis KIM5 (lacking pgm) generated the CD4 and CD8 T cells that synergistically conferred protection against plague, but T cells from those vaccinated mice could not recognize LcrV (47).…”

Respiratory immunity is an important component of protection elicited by subunit vaccination against pneumonic plague

“…Other studies looking at the antibody response to F1 or V in mice have primarily focused on the response in the sera; few have looked at antibody levels in the respiratory tract. Williamson et al, who used a combination of the F1 and V subunit vaccines, found low titers of antibody in the lung compared with significantly higher levels in sera for both F1 and V [8]. They suggested that because of the higher levels of specific antibody found in the sera, serum titers were a better correlate of immunity than antibody from the lung.…”

“…Live, attenuated vaccines protect well against bubonic and pneumonic plague, but there have been adverse events associated with their use [2]. Subunit vaccines, developed from antigenic components of Y. pestis, in contrast, can successfully protect against both bubonic and pneumonic plague, and these vaccine products appear to be safe in animal models [6][7][8][9][10][11][12][13][14][15][16].…”

“…Vaccination with V alone is sufficient for protecting mice against both bubonic and pneumonic plague [14]. Postulated subunit vaccine candidates for plague use either a combination of F1 and V, or a recombinant fusion of the two [8,9]. Subunit vaccines comprised of other proteins from Y. pestis have been evaluated and have demonstrated efficacy, but not to the same degree as F1 and V, either alone or in combination [23].…”

Plague virulence

“…A killed whole-cell vaccine is available, but the shortlived and variable protection it affords combined with the high level of adverse reactions make it unsuitable for general use. A second-generation vaccine based on puri®ed protein antigens, which will protect against both bubonic and pneumonic plague, is in development [3]. The epidemiology and distribution of the organism, and the recommended surveillance and control measures employed are reviewed in detail in the WHO Plague Manual [1].…”