The quadrivalent human papillomavirus (HPV) vaccine prevented genital wart acquisition among women in clinical trials , but its effect at the population level is just beginning to be evaluated. In Denmark, routine free HPV vaccination of 12-year-old girls was introduced in 2009, and the current estimated coverage is 80% for all three doses. Now, investigators have assessed the incidence of genital warts in 55% of the Danish population from 1996 to 2011. Annual incidence of genital warts rose in both women and men from 1996 to 2008, when a downward turn was noted among women but not men. This reduction was especially pronounced among 16- to 17-year-old women, in whom incidence fell 10-fold (from 382 per 100,000 to 40 per 100,000). During this period, prevalence of chlamydia and syphilis continued to rise.

Comment: The drop in prevalence of genital warts but not other sexually transmitted diseases suggests that the human papillomavirus vaccine — and not a behavioral change in the target population — was primarily responsible for this beneficial outcome. It also indicates the need to vaccinate both men and women. Such studies also demonstrate how countries with healthcare systems that allow for efficient delivery of preventive care as well as rapid assessment of the benefits at the national level. The U.S. would do well to learn from such successes.

CITATION: Baandrup L et al. Significant decrease in the incidence of genital warts in young Danish women after implementation of a national human papillomavirus vaccination program. Sex Transm Dis 2013 Feb; 40:130.

Published in Journal Watch Women’s Health