Table 3.
Distributions of ELISA serum antibody concentration levels and SEAP neutralization titers for HPV16 and HPV18 at years nine and 11
| Assay | Metric | Three doses |
Two doses (0/6 mo) |
One dose |
|||
|---|---|---|---|---|---|---|---|
| GM (95% CI) | IQR | GM (95% CI) | IQR | GM (95% CI) | IQR | ||
| HPV 16 ELISA antibody concentration | |||||||
| ELISA antibody concentration, EU/mL | Year 9 | 699 (606 to 807) | 394–1265 | 414 (328 to 524) | 197–813 | 172 (141 to 209) | 83–319 |
| Year 11 | 664 (570 to 772) | 383–1309 | 340 (267 to 434) | 170–684 | 176 (145 to 214) | 84–370 | |
| Change, % (95%CI) | –1.6 (–8.6 to 5.5) | –17.9 (–28.5 to –7.4) | 0.3 (–13.4 to 13.9) | ||||
| Ratio of GM | 0.95 (0.89–1.01) | 0.82 (0.76–0.89) | 1.03 (0.94–1.13) | ||||
| HPV18 ELISA antibody concentration | |||||||
| ELISA antibody concentration, EU/mL | Year 9 | 292 (249 to 342) | 163–532 | 210 (171 to 259) | 119–426 | 102 (83 to 125) | 48–223 |
| Year 11 | 275 (234 to 323) | 160–518 | 194 (156 to 241) | 117–384 | 109 (89 to 133) | 51–220 | |
| Change, % (95%CI) | –4.0 (–13.6 to 5.6) | –2.1 (–22.5 to 18.4) | –1.3 (–14.0 to 11.5) | ||||
| Ratio of GM | 0.94 (0.88–1.01) | 0.92 (0.83–1.02) | 1.07 (0.99–1.16) | ||||
| HPV 16 SEAP-NA neutralization titer | |||||||
| SEAP-NA antibody titer | Year 9 | 1776 (1389 to 2270) | 1014–3114 | 771 (612 to 970) | 382–1484 | 285 (229 to 355) | 120–654 |
| Year 11 | 1565 (1227 to 1997) | 924–2916 | 626 (491 to 798) | 323–1405 | 285 (233 to 349) | 133–608 | |
| Change, % (95%CI) | –10.5 (–21.7 to 0.7) | –17.2 (–28.1 to –6.4) | –11.5 (–29.7 to 6.7) | ||||
| Ratio of GM | 0.88 (0.81–0.96) | 0.81 (0.75–0.88) | 1.00 (0.90–1.11) | ||||
| HPV18 SEAP-NA neutralization titer | |||||||
| SEAP-NA antibody titer | Year 9 | 856 (645 to 1136) | 425–1615 | 531 (415 to 678) | 295–1092 | 216 (170 to 273) | 93–504 |
| Year 11 | 792 (588 to 1065) | 371–1573 | 489 (371 to 644) | 217–1080 | 233 (184 to 296) | 96–551 | |
| Change, % (95%CI) | –2.6 (–15.9 to 10.6) | 14.6 (–33.2 to 62.4) | 6.8 (–7.4 to 21.0) | ||||
| Ratio of GM | 0.92 (0.81–1.06) | 0.92 (0.80–1.06) | 1.08 (0.98–1.19) | ||||
*
CI = confidence interval; ELISA = enzyme-linked immunosorbent assay; GM = geometric mean; IQR = interquartile range; SEAP-NA = secreted alkaline phosphatase-based pseudovirion neutralization assay.