Potential impact of the human papillomavirus vaccine on the incidence proportion of genital warts in French women (EFFICAE study): a multicentric prospective observational study

Background The objective was to evaluate the effect of a HPV vaccination program on the incidence proportion of a proxy, genital warts (GW), in women in France. Methods: The number of primary GW cases was prospectively recorded over two 4-month periods before (T0: Dec 2008 to March 2009) and after (T1: Dec 2011 to March 2012) a HPV vaccination program. A total of 160 gynaecologists participated in T0 and 189 in T1. Primary genital herpes (HSV) infection was used as a control. Results: During T0, 39 190 15- to 26 year-old women were seen, of whom 176 were diagnosed with GW (incidence proportion: 0.45%) and 155 with primary HSV infection (incidence proportion: 0.39%). During T1, 45 628 females were seen [229 with GW (incidence proportion: 0.50%) and 202 with HSV (incidence proportion: 0.44%)]. In the 15–20 years age category, the incidence proportion of primary GW decreased from 0.41% to 0.30% (P = 0.128) between T0 and T1, and the proportion of women newly diagnosed with primary genital herpes diseases slightly increased from 0.34% to 0.38% (P = 0.620). In the 15–18 years age group, this decrease became significant (0.34% to 0.18%; P = 0.048). Conclusions: A trend for a non-significant decreased incidence proportion of GW was observed in young women below 20 years who are more frequently vaccinated. This may be the result of HPV vaccination and suggests that a substantial increase in vaccine coverage could lead to a more pronounced decreased incidence proportion of GW in the future.