When measured with C6-depleted match and added PMNs, the percentages of preimmunization sera with OP bactericidal titers of 1 1:5 in both vaccine organizations combined were 9% (3/32), 3% (1/31), and 16% (5/32) against strains H44/76, S3032, and NZ98/254, respectively

When measured with C6-depleted match and added PMNs, the percentages of preimmunization sera with OP bactericidal titers of 1 1:5 in both vaccine organizations combined…