Table 3.
Vaccine Effectiveness (VE) Against Human Papillomavirus (HPV) Infection in 1454 Study Participants Who Were Vaccinated Before Sexual Debut
| Variable | Vaccinated, No. (%) (n = 1000) |
Unvaccinated, No. (%) (n = 454) |
Univariate Analysis | ||
|---|---|---|---|---|---|
| PR (95% CI) | VE, % (95% CI) | P b | |||
| High-risk HPVa | 79 (7.9) | 69 (15.2) | 0.52 (.38–.70) | 48.0 (29.6–61.6) | <.01c |
| HPV16/18 | 1 (0.1) | 10 (2.2) | 0.05 (.01–.35) | 95.5 (64.6–99.4) | <.01c |
| HPV31/45/52 | 13 (1.3) | 21 (4.6) | 0.28 (.14–.56) | 71.9 (44.4–85.8) | <.01c |
| HPV16 | 1 (0.1) | 8 (1.8) | 0.06 (.01–.45) | 94.3 (54.8–99.3) | <.01c |
| HPV18 | 0 (0) | 2 (0.4) | 0.00 … | 100.0 … | .09 |
| HPV31 | 0 (0) | 4 (0.9) | 0.00 … | 100.0 … | .01c |
| HPV33 | 2 (0.2) | 2 (0.4) | 0.45 (.06–3.21) | 54.6 (−221.3– 93.6) | .59 |
| HPV35 | 2 (0.2) | 0 (0.0) | ∞ … | −∞ … | 1.00 |
| HPV39 | 8 (0.8) | 5 (1.1) | 0.73 (.24–2.21) | 27.4 (−120.8–76.1) | .55 |
| HPV45 | 0 (0) | 2 (0.4) | 0.00 … | 100.0 … | .09 |
| HPV51 | 6 (0.6) | 6 (1.3) | 0.45 (.15–1.40) | 54.6 (−40.0–85.3) | .20 |
| HPV52 | 13 (1.3) | 16 (3.5) | 0.37 (.18–.76) | 63.1 (24.0–82.1) | .01c |
| HPV56 | 17 (1.7) | 9 (2.0) | 0.86 (.39–1.91) | 14.2 (−90.9–61.5) | .67 |
| HPV58 | 14 (1.4) | 9 (2.0) | 0.71 (.31–1.62) | 29.4 (−62.0–69.2) | .36 |
| HPV59 | 12 (1.2) | 4 (0.9) | 1.36 (.44–4.20) | −36.2 (−320.0–55.8) | .79 |
| HPV68 | 7 (0.7) | 3 (0.7) | 1.06 (.28–4.08) | −5.9 (−307.8–72.5) | 1.00 |
Abbreviations: CI, confidence interval; PR, prevalence ratio.
aDefined as HPV16/18/31/33/35/39/45/51/52/56/58/59/68 (detected by the HCII assay).
bBy the Fisher exact test.
c P <.05.