Early Evidence of the Effectiveness of the Human Papillomavirus Vaccination Program Against Anogenital Warts in Manitoba, Canada: A Registry Cohort Study
Bibliographic record
Abstract
BACKGROUND: We assessed the effectiveness of the quadrivalent human papillomavirus vaccine (qHPV) vaccination program in Manitoba, Canada, in reducing incident anogenital warts (AGWs) and to what extent effectiveness depends on age at vaccination and number of doses. METHODS: Female participants 9 years or older who received the qHPV in Manitoba between September 2006 and March 2013 (n = 31,464) through the publicly funded school-based program and a high-risk catch-up program were included. They were matched on age and area of residence to unvaccinated female participants. Information on incident AGWs was obtained from provincial administrative databases using validated algorithms. Using stratified Cox regression models, we estimate hazard ratios (HRs) for the association between qHPV and AGWs. RESULTS: For female participants vaccinated at age 18 years or younger, receipt of qHPV was associated with a 40% reduction in AGW risk (HR, 0.6; 95% confidence interval [CI], 0.4-0.8). Further adjustment for socioeconomic and medical history did not alter this estimate. For women vaccinated at age 19 years or older, we saw an increase in AGW incidence, especially among those who were sexually active (HR, 2.8; 95% CI, 2.1-3.7). Among female participants vaccinated at age 18 years or younger, risk of AGWs was lowest among those who received 3 doses, corresponding to a vaccine effectiveness of 56% (95% CI, 30%-70%). For women vaccinated at older age, risk of AGWs remained increased regardless of the number of doses. CONCLUSIONS: Women vaccinated at an older (≥19 years) age may be less protected against AGWs, particularly if sexually active before vaccine administration. Further efforts should be targeted at increasing vaccine uptake among preadolescents before the initiation of sexual activity.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.007 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.005 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".