TABLE 3.

Comparison of antibody titers elicited in individual mice vaccinated with either Y. pestis Kimberley53pcm or EV76 strain and survival after lethal challengea

Kimberley53 challenge doseAntibody titers and survival after vaccination with:
Kimberley53pcm vaccineEV76 vaccine
105 CFU106 CFU105 CFU106 CFU
Anti-V antigenAnti-F1 antigenSurvivalbAnti-V antigenAnti-F1 antigenSurvivalAnti-V antigenAnti-F1 antigenSurvivalAnti-V antigenAnti-F1 antigenSurvival
103 LD5010025,000+6,400100,000+10320320640+
20025,000+2,50050,000+<10160+40160+
80012,500+1050,000+<1080<10160+
10012,500+2025,000+10402080+
2012,500+1025,000+<1020<1020
1,6006,400+6,40012,500+<1010<1010
106,400+1,60012,500+<101020<10
1003,2004012,500+10<1020<10
803,200+103,200+<10<10<10<10
203,200+<10<10<10
105 LD5080025,000+4050,000+<10640<10320+
1025,000+2050,000+<10320+1080
12,50025,000+80025,000+<101602040
2012,500+80012,500+<1020<1040+
1012,500+6,4006,400+<10102010+
1012,500+4006,400+<10<101010
4006,400+406,400+<10<1020<10
4006,400+1,6003,200+<10<1010<10
1003,200+1003,200+<10<10<10<10
103,200+NDcND+<10<10<10<10
  • a Four groups of animals (20 mice each) were vaccinated once s.c. with a dose of 105 or 106 CFU of strain Kimberley 53pcm or EV76. Anti-F1 and anti-V ELISA titers for each animal were determined 46 days following vaccination (titers of <10 were observed in the control group). Animals were challenged, 50 days postvaccination, with the virulent Kimberley 53 strain, and survival of mice was monitored for 21 days. None of the mice in the control group survived (data not shown).

  • b +, survived; −, did not survive.

  • c ND, not done.