Impact of quadrivalent human papillomavirus vaccine on genital warts in an opportunistic vaccination structure

Objective Genital warts are the most common sexually transmitted disease and have a detrimental impact on quality of life. Genital warts could be prevented by prophylactic HPV vaccination. The objective was to study real-life benefit of opportunistic HPV vaccination on age and gender specific incidence of genital warts. Methods We performed a register-based population cohort study from publicly funded health-care provider in Israel. The incidence of genital warts was assessed during three time frame intervals: 2006–2008 (pre-vaccination effect period) 2009–2012 (early post-vaccination effect period) and 2013–2015 (late post-vaccination effect period), with an average annual number of members of 1,765,481, 1,906,774 and 2,042,678 in the years 2006–2008, 2009–2012 and 2013–2015, respectively. Results Among females, annual incidence of genital warts per 100,000 women decreased from 210.43 to 161.71 (OR 0.76, 95%CI 0.71–0.82, p < 0.001) and to 146.8 (OR 0.69, 95%CI 0.66–0.72, p < 0.001) between pre-vaccination period and early and late post-vaccination periods, respectively. Among males, annual incidence of genital warts per 100,000 men decreased from 262.85 to 232.40 (OR 0.88, 95%CI 0.83–0.93, p < 0.001) and to 234.01 (OR 0.88, 95%CI 0.86–0.91, p < 0.001) between pre-vaccination period and early and late post-vaccination periods, respectively. Conclusions There is a potential benefit in reducing incidence of genital warts even in opportunistic HPV vaccination structure. This information may be relevant for health-care providers in countries where national immunization programs do not include HPV vaccines.