Prevention of Persistent Human Papillomavirus Infection by an HPV16/18 Vaccine: A Community-Based Randomized Clinical Trial in Guanacaste, Costa Rica
Authors
Discussion
Loading...
Member takes
Implication
Randomized trial reveals high HPV16/18 vaccine efficacy against persistent infection in young women, indicating maximal protection when administered before sexual debut.
Key Points
- To evaluate the efficacy of an HPV16/18 vaccine against one-year persistent human papillomavirus infection among young women, stratified by age and sexual behavior.
- Randomized trial allocating 7,466 healthy women aged 18 to 25 years in Costa Rica to receive either the HPV16/18 vaccine or a control hepatitis A vaccine, with a mean follow-up of 50.4 months.
- Evaluated outcomes using an according-to-protocol (ATP) cohort of compliant, baseline HPV-negative women and an intention-to-treat (ITT) cohort including all randomized women.
- ATP vaccine efficacy was 90.9% (95% CI, 82.0–95.9) against HPV16/18 infections, 44.5% (95% CI, 17.5–63.1) against HPV31/33/45 infections, and 12.4% (95% CI, −3.2 to 25.6) against any oncogenic infection.
- Overall ITT vaccine efficacy against HPV16/18 was 49.0%, with efficacy approaching 100% in year 4 of follow-up across both ATP and ITT cohorts.
- ITT vaccine efficacy against HPV16/18 was substantially higher among younger participants (68.9% among those aged 18–19 years vs. 21.8% among those aged 24–25 years) and reached 79.8% among virgins.
Cite This Study
Herrero et al. (2011) studied this question.