Genital warts in young Australians five years into national human papillomavirus vaccination programme: national surveillance data

OBJECTIVE: To measure the effect on genital warts of the national human papillomavirus vaccination programme in Australia, which started in mid-2007. DESIGN: Trend analysis of national surveillance data. SETTING: Data collated from eight sexual health services from 2004 to 2011; the two largest clinics also collected self reported human papillomavirus vaccination status from 2009. PARTICIPANTS: Between 2004 and 2011, 85,770 Australian born patients were seen for the first time; 7686 (9.0%) were found to have genital warts. MAIN OUTCOME MEASURE: Rate ratios comparing trends in proportion of new patients diagnosed as having genital warts in the pre-vaccination period (2004 to mid-2007) and vaccination period (mid-2007 to the end of 2011). RESULTS: Large declines occurred in the proportions of under 21 year old (92.6%) and 21-30 year old (72.6%) women diagnosed as having genital warts in the vaccination period-from 11.5% in 2007 to 0.85% in 2011 (P<0.001) and from 11.3% in 2007 to 3.1% in 2011 (P<0.001), respectively. No significant decline in wart diagnoses was seen in women over 30 years of age. Significant declines occurred in proportions of under 21 year old (81.8%) and 21-30 year old (51.1%) heterosexual men diagnosed as having genital warts in the vaccination period-from 12.1% in 2007 to 2.2% in 2011 (P<0.001) and from 18.2% in 2007 to 8.9% in 2011 (P<0.001), respectively. No significant decline in genital wart diagnoses was seen in heterosexual men over 30 years of age. In 2011 no genital wart diagnoses were made among 235 women under 21 years of age who reported prior human papillomavirus vaccination. CONCLUSIONS: The significant declines in the proportion of young women found to have genital warts and the absence of genital warts in vaccinated women in 2011 suggests that the human papillomavirus vaccine has a high efficacy outside of the trial setting. Large declines in diagnoses of genital warts in heterosexual men are probably due to herd immunity.