TABLE 3.

Serum HAI antibody seroconversion rates to the A/H1N1, A/H3N2, and B influenza virus strains

Serostatus,b strain, and treatmentncSerum HAI seroconversiona
No. (%)Significanced
All subjects
    A/H1N1
        CAIV-T 107408 (20.0)N/A
        CAIV-T <105402 (5.0)0.087
        TIV4215 (35.7)0.143
        Placebo403 (7.5)0.193
    A/H3N2
        CAIV-T 1074028 (70.0)N/A
        CAIV-T <105403 (7.5)<0.001
        TIV4210 (23.8)<0.001
        Placebo404 (10.0)<0.001
    B
        CAIV-T 1074021 (52.5)N/A
        CAIV-T <105397 (17.9)0.002
        TIV4212 (28.6)0.042
        Placebo397 (17.9)0.002
Seronegative subjects
    A/H1N1
        CAIV-T 107337 (21.1)N/A
        CAIV-T <105291 (3.4)0.057
        TIV305 (16.7)0.754
        Placebo303 (10.0)0.308
    A/H3N2
        CAIV-T 1073327 (81.8)N/A
        CAIV-T <105343 (8.8)<0.001
        TIV357 (20.0)<0.001
        Placebo344 (11.8)<0.001
    B
        CAIV-T 1072719 (70.4)N/A
        CAIV-T <105215 (23.8)0.003
        TIV265 (19.2)<0.001
        Placebo246 (25.0)0.002
  • a Seroconversion to a particular virus strain was defined as a ≥1:4-fold rise from baseline in the titer of HAI antibody to that strain.

  • b A subject was seronegative to a particular strain if his or her prevaccination HAI titer to that strain was ≤1:4.

  • c Number of subjects with complete data.

  • d P values based on comparison with the CAIV-T 107 treatment group were calculated by a two-sided Fisher exact test.