Efficacy of HPV vaccination on all-type cervical abnormalities in HPV-naïve women reported in the literature
| Study | Study design | Setting/year | Study population (stratum of study population included) | Outcome measure reported | Reported vaccine efficacy, % reduction (95% CI) | |||
|---|---|---|---|---|---|---|---|---|
| ASCUS+ | Any cervical biopsy | CIN2+ | CIN3+ | |||||
| Munoz et al27 | Randomised controlled trial | Multinational 2001–2006 | 16–26 years+several other criteria* | Rate ratio | 17.1 (10 to 23) | 22 (16 to 30) | 42.7 (23.7 to 57.3) | 43† (13.0 to 63.2) |
| Crowe et al28 | Nested case–control study | Queensland, Australia 2007–2011 | 15–18 years in 2007, presenting for first smear, received all 3 doses of vaccine | OR | NA | NA | 60 (44 to 70)‡ | NA |
| Gertig et al25 | Data linkage study | Victoria, Australia 2007–2011 | ≤17 years in 2007, had started cervical screening, received all 3 doses of vaccine | HR | NA | NA | 39 (22 to 52) | 47 (23 to 64) |
| Baldur-Felskov et al36 | Cohort study | Denmark 2006–2012 | 14–15 years in 2008 (1993–1994 cohort), had a history of cervical cytology | HR | § | NA | 67 (17 to 87) | 75* 10 to 93) |
| Mahmud et al37 | Cohort study | Manitoba, Canada 2006–2011 | 14–17 years in 2006–2010, had ≥1 Pap smear | HR | 45 (32 to 56) | NA | NA | NA |
| Pooled estimate | 32 | 22 | 49 | 47 | ||||
*(1) Participants had 0–4 sex partners during their lifetime; (2) no history of abnormal Pap smear test; (3) no history of genital warts; (4) no genital wart detected at enrolment; (5) received at least one vaccination; (6) were seronegative; HPV 6, 11, 16 and 18 negative, and negative for 10 other HPV types at enrolment; (7) had a negative day 1 Pap smear test and (8) had any follow-up visit.
†The reported vaccine effect is on CIN3, not CIN3+. No cases of higher grade of severity are reported.
‡Relative risk calculated from reported data.
§Vaccine efficacy on ‘atypia or worse’ of 53% is not included in our pooled estimate, because this classification includes reactive changes.
ASCUS, Atypical Squamous Cells of Undetermined Significance; CIN, cervical intraepithelial neoplasia; HPV, human papillomavirus; NA, not applicable.