Oral administration of Lip-LcrV L. plantarum is not protective. a, 50% maximum binding titers were calculated for total LcrV specific Ig levels in mice vaccinated and boosted with Lip-LcrV L. plantarum(n=10), L. plantarum transfected with plasmid lacking LcrV (empty vector) (n=10), or IM with rLcrV in alum(n=5). b, survival of mice orally vaccinated and boosted with Lip-LcrV L. plantarum, empty vector or vaccinated and boosted IM with rLcrV in alum after challenge with 10× LD50 or 100× LD50 of Y. pestis CO92pgm−. These data are representative of two experiments. *-p<0.01 rLcrV IM 10 or 100 LD50 vs all other groups.