- Catch-up, 3-dose HPV vaccination prevents cervical intraepithelial neoplasia (CIN) cancer (CIN2+, CIN3+) in women aged 20 years at the time of first dose.
Why this matters
- Although the focus of HPV vaccination should continue to be younger adolescents (age, 11-12 years), importance/potential effectiveness of catch-up dosing in women up to age 20 years should not be overlooked.
- 4357 patients with CIN2+, 21,773 matched control patients; subset included 1849 patients with CIN3+, 9242 matched control patients.
- ≥1 vaccine dose decreased overall CIN2+ risk vs no vaccination (adjusted risk ratio [aRR]=0.82; 95% CI, 0.73-0.93).
- Adjusted models based on age at first dose, number of doses: decreased risk seen only in women aged 14-17 (aRR=0.52; 95% CI, 0.36-0.74) and 18-20 years (aRR=0.65; 95% CI, 0.49-0.88) at first dose receiving ≥3 doses.
- For combined adjusted modeling based on dose number/age at first dose, protection against CIN3+ seen in women receiving ≥3 doses and first dose at age 14-17 years (aRR=0.27; 95% CI, 0.13-0.56).
- Nested, case-control evaluation of the effectiveness of catch-up quadrivalent HPV vaccine against CIN2+, 3+ by age at first dose and number of doses.
- Funding: National Cancer Institute.
- Misclassification bias.
- Residual confounding.
- Study design precluded absolute rates calculation.
- Limited generalizability.