Vaccine group | No. of subjects | IgG GMC (μg/ml) | rSBA GMT | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|

Serogroup C | Serogroup Y | Serogroup C | Serogroup Y | ||||||||||

Baseline | Post-vax | Mean change | Baseline | Post-vax | Mean change | Baseline | Post-vax | Mean change | Baseline | Post-vax | Mean change | ||

Group 1 (ref group), MenACWY only | 41 | 0.09 | 0.24 | 2.8 | 0.95 | 2.68 | 2.8 | 7.53 | 123.69 | 16.4 | 39.45 | 105.45 | 2.7 |

Group 2, Plus Tdap only | 24 | 0.03 | 2.22 | 82.3 | 2.09 | 35.72 | 17.1 | 4.22 | 1284.65 | 304.2 | 21.46 | 632.16 | 29.5 |

Group 3, Plus 4, not Tdap/IPV | 105 | 0.03 | 0.66 | 21.9 | 1.32 | 14.02 | 10.7 | 10.98 | 348.64 | 34.4 | 17.28 | 436.29 | 25.4 |

Group 4, Plus 4, not Tdap | 150 | 0.04 | 1.28 | 33.0 | 1.21 | 14.97 | 12.4 | 4.12 | 392.43 | 95.8 | 23.43 | 1036.92 | 44.7 |

P value^{b} | 0.003 | 0.016^{c} | 0.001 | 0.002 |

↵a Abbreviations: GMC, geometric mean concentration (μg/ml); GMT, geometric mean titer; IgG, immunoglobulin G; IPV, inactivated polio vaccine; MenACWY, tetravalent meningococcal conjugate vaccine A, C, W, and Y; Post-vax, postvaccination; rSBA, rabbit complement serum bactericidal antibody assay; ref, reference; Tdap, tetanus-diphtheria-acellular pertussis vaccine.

↵b Kruskal-Wallis

*P*values were calculated for testing the null hypothesis that the distribution of values across the four vaccine groups was the same.↵c This

*P*value is not statistically significant with a Bonferroni adjustment to the alpha level of 0.0125.