Fewer teens and young women getting genital warts thanks to HPV vaccine program

Ontario’s human papillomavirus (HPV) vaccination program has led to a drop in young women contracting genital warts, new research from Public Health Ontario (PHO) and the Institute for Clinical Evaluative Sciences (ICES) has found.

Genital warts are a sexually transmitted infection caused by certain strains of HPV and can cause pain, discomfort and itching. Certain types of HPV are especially dangerous for women because they can also cause cancer of the cervix and vulva. In a new paper in Vaccine, researchers examined the impact of Ontario’s HPV vaccination program on the incidence of genital warts in the province by comparing data before and after the introduction of the program.

“The analysis was very clear – we saw a marked decrease in genital warts among young women when we compared the pre- and post-immunization program periods,” says Dr. Shelley Deeks, PHO medical director of immunization and vaccine-preventable disease and senior author on the paper

Ontario’s HPV vaccination program began in 2007 for Grade 8 girls (those born in 1994). Deeks and fellow researchers from PHO and ICES looked at doctor’s office visits for genital warts in patients 15 years and older. A total of 286,609 anonymized records spanning a 10-year period (2004-2014) were included in the study.

When comparing pre- and post-immunization time periods, doctor’s office visits for genital warts decreased by 10-14 per cent in young women 15-23 years of age.

“While we found a positive effect of the province’s HPV vaccine program in Ontario teens and young women, we did not see evidence of herd immunity in young men. However, data from the study’s later years (2011-2013) did suggest that doctor’s office visits for genital warts among young men was going down, which is encouraging and needs to be followed,” says Dr. Deeks.

The authors say further research is needed, especially since Ontario boys will be eligible to receive the publicly-funded HPV vaccine starting in the 2016-17 school year.

The paper titled Early Impact of Ontario’s human papillomavirus (HPV) vaccination program on anogenital warts (AGWs): A Population-Based Assessment is in the current edition of Vaccine.