Table 2.
Overall Protective Effectiveness (With 95% Confidence Interval) Against Genital Human Papillomavirus (HPV) Infection and Type-Specific HPV Prevalence (%) by HPV Vaccination Strategya and Birth Cohort
| Arm A (Gender-Neutral) | Arm B (Girls-Only) | Arm C (Control) | ||||
|---|---|---|---|---|---|---|
| Birth Cohorts | Prevalence (95%CI) | PEb (95% CI) | Prevalence (95% CI) | PEb (95% CI) | Prevalence (95% CI) | |
| HPV Type | ||||||
| HPV16 | 1992–1995 | 4.1 (3.2–5.2) | 53.3 (40.1–64.9)c | 4.3 (3.5–5.4) | 42.0 (27.9–54.4)c | 8.1 (7.3–9.1) |
| 1995 | 5.0 (3.2–8.0) | 35.5 (2.5–61.1)c | 5.0 (3.3–7.5) | 32.4 (2.6–56.6)c | 7.7 (6.1–9.8) | |
| HPV18 | 1992–1995 | 2.6 (1.9–3.6) | 38.5 (17.6–56.1)c | 2.2 (1.6–3.0) | 51.5 (34.4–65.9)c | 5.0 (4.3–5.8) |
| 1995 | 1.1 (0.4–2.9) | 76.5 (47.6–92.6)c | 1.6 (0.7–3.4) | 57.9 (25.1–80.4)c | 2.7 (1.8–4.1) | |
| HPV31 | 1992–1995 | 2.2 (1.6–3.0) | 40.5 (17.9–58.6)c | 2.4 (1.8–3.2) | 32.0 (8.9–51.1)c | 3.8 (3.2–4.5) |
| 1995 | 0.7 (0.3–1.8) | 79.9 (55.6–90.6)c | 1.9 (1.0–3.7) | 53.8 (16.6–77.4)c | 3.4 (2.3–4.9) | |
| HPV33 | 1992–1995 | 2.2 (1.7–3.0) | −4.0 (−45.1 to 28.4) | 2.3 (1.7–3.0) | −25.9 (−70.9 to 10.9) | 2.1 (1.7–2.7) |
| 1995 | 1.0 (0.4–2.5) | 50.1 (0.9–73.9)c | 1.1 (0.5–2.3) | 33.4 (−24.4 to 66.4) | 1.4 (0.8–2.5) | |
| HPV35 | 1992–1995 | 0.9 (0.5–1.3) | 45.2 (11.1–68.6)c | 1.1 (0.8–1.6) | 32.3 (−1.9 to 56.9) | 1.6 (1.3–2.1) |
| 1995 | 1.0 (0.4–2.6) | 23.8 (−61.4 to 68.1) | 1.1 (0.5–2.3) | 7.5 (−69.9 to 52.6) | 2.1 (1.3–3.3) | |
| HPV45 | 1992–1995 | 1.7 (1.2–2.5) | 19.8 (−15.1 to 47.4) | 1.4 (0.9–2.0) | 35.1 (5.9–57.9)c | 2.5 (2.0–3.1) |
| 1995 | 1.4 (0.6–3.3) | 37.7 (−35.9 to 78.1) | 0.7 (0.2–1.8) | 67.6 (20.4–90.4)c | 2.1 (1.3–3.4) | |
| HPV18/31/33 | 1992–1995 | 6.4 (5.3–7.6) | 15.3 (−0.6 to 29.9) | 6.2 (5.2–7.3) | 30.6 (17.4–42.9)c | 10.9 (9.9–12.0) |
| 1995 | 2.8 (1.6–4.8) | 65.6 (46.1–78.9)c | 4.3 (2.8–6.6) | 46.8 (24.4–64.4)c | 8.4 (6.6–10.5) |
Abbreviations: CI, confidence interval; PE, protective effectiveness.
aArm A, gender-neutral (49% girls, 23% boys HPV-vaccinated); Arm B, girls-only (47% girls HPV-vaccinated); Arm C, hepatitis B-virus vaccination.
bPE = overall protective effectiveness, a combination of vaccine efficacy and herd effects weighted by the proportions of HPV16/18-vaccinated and non-HPV16/18-vaccinated women, respectively.
cSignificant.