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.