TABLE 1.

OP bactericidal activity of postimmunization sera in relation to BA

BA titer group and vaccineSera with OP titer of ≥1:5a
Strain H44/76Strain S3032Strain NZ98/254
No. positive/total no. tested% Positive (95% CI)No. positive/total no. tested% Positive (95% CI)No. positive/total no. tested% Positive (95% CI)
BA titers of ≥1:4
    OMV9/1275 (43-95)7/978 (40-97)7/7100 (59-100)
    OMV/GNA213211/11100 (72-100)10/1377 (46-95)5/683 (36-100)
BA titers of <1:4
    OMV0/50b (0-53)0/80 (0-37)2/1020 (3-56)
    OMV/GNA21323/475b (19-99)1/250 (1-99)5/956 (21-86)
  • a The proportion of postimmunization sera with OP bactericidal activity, stratified by the presence or absence of a complement-mediated BA titer of ≥1:4 and by vaccine group. The CI was calculated from the binomial distribution.

  • b P < 0.05 by the Fisher exact test. Other differences in respective percentages of OP activity between the OMV and OMV/GNA2132 vaccine groups were not significant (P > 0.16).