Table 3.

HPV16 and HPV18 antibody stability between months 24, 36, and 48 by number of doses

1-dose2-doses(0/1)2-doses(0/6)3-dosesP-value
24–48 months n (%)
HPV16a
Stablec68 (87.18)128 (91.43)43 (82.69)106 (88.33)0.30
Decreasec10 (12.82)12 (8.57)9 (17.31)14 (11.67)
HPV18b
Stable71 (91.03)128 (91.42)43 (82.69)103 (85.83)0.24
Decrease7 (8.97)12 (8.57)9 (17.31)17 (14.17)
36–48 months n (%)
HPV16
Stable decrease74 (94.87)136 (97.14)51 (98.08)117 (97.50)0.69
4 (5.13)4 (2.86)1 (1.92)3 (2.50)
HPV18
Stable72 (92.31)134 (95.71)51 (98.08)118 (98.33)0.15
Decrease6 (7.69)6 (4.29)1 (1.92)2 (1.67)
  • aHPV16 Spearman's rank correlation coefficient at 24- and 48-month visits was 0.88 (P < 0.0001).

  • bHPV18 Spearman's rank correlation coefficient at 24- and 48-month visits was 0.90 (P < 0.0001).

  • cStable antibodies defined as levels that did not decline by 2-fold or more; a decrease in antibodies as those that declined 2-fold or more.