Impact of quadrivalent human papillomavirus vaccine in women at increased risk of genital warts burden: Population-based cross-sectional survey of Czech women aged 16 to 40 years.

BACKGROUND

To assess the impact of a quadrivalent human papillomavirus vaccine (4HPV) in women at increased risk of genital warts (GWs) acquisition.

METHODS

The study was conducted using a population-based cross-sectional survey of 19,199 women aged 16 to 40 years randomly chosen from the general population in the Czech Republic between January 2013 and March 2014. A total of 1086 women reported having received the 4HPV vaccine. The vaccine's effectiveness was estimated not only in the general population of women but also in those at increased risk due to having a sexual partner with GWs or prior GWs history.

RESULTS

The acquisition of GWs was dramatically reduced by 90.6% (80.1-95.6%) in immunised women at least one year after the completion of the 4HPV vaccination in comparison with unimmunised women. Recurrent GWs prevalences of 1.1% (95% CI, 0.0-5.9) and 10.9% (95% CI, 9.1-12.9) in immunised and unimmunised women with prior GWs history, respectively, resulted in a vaccine effectiveness of 89.0% (38.6-98.0%). The notably strong protective effect of 4HPV immunisation in women who had a sexual partner with GWs was demonstrated by a very low age-adjusted odds ratio of 0.02 (95% CI 0.01-0.10) in contrast to unimmunised women.

CONCLUSIONS

To lower the chance of genital warts acquisition in the general population and in populations at increased risk, only current 4HPV or incoming 9HPV vaccination should be recommended to provide effective protection.