Success of the Free HPV Vaccine

Genital warts cases down since introduction of HPV vaccine program in Australia

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) It's icing on the cake when a vaccine is offered for little to no cost. Free human papilloma virus (HPV) vaccine programs can protect many individuals from genital warts without draining their bank accounts.

The number of human papilloma virus (HPV) cases in both men and women has dropped significantly since the introduction of the free HPV vaccine program in Australia, according to a recently published study.

The decline suggests that the vaccine worked effectively among young women and girls, with men protected by those who were already vaccinated, according to the study's authors.

"Ask your doctor about HPV vaccination."

Hammad Ali, lecturer at the Kirby Institute at the University of New South Wales in Australia, and colleagues investigated how Australia's national HPV vaccine program affected genital warts trends across the country.

Genital warts are caused by HPV through sexual contact. The HPV vaccine program, which started in 2007 and was one of the first of its kind in the world, offers free vaccinations to 12- and 13-year-old girls.

The study included more than 85,000 patients being treated at eight sexual health clinics between 2004 and 2011. In total, 7,686 patients, or 9 percent of that population, had genital warts.

The researchers designated the years 2004 to mid 2007 as the pre-vaccination period and mid 2007 to the end of 2011 as the vaccination period.

They then compared the proportion of patients who were newly diagnosed with genital warts during the first time frame to the second time frame.

At two of the largest clinics involved in the study, patients reported whether they had received the HPV vaccine.

During the vaccination period, genital warts declined about 93 percent in women under 21 years of age and about 73 percent in women between 21 and 30 years of age, the researchers found.

Specifically, the proportion of women under 21 who were diagnosed with genital warts went down from 11.5 percent in 2007 to 0.85 percent in 2011.

Among women between 21 and 30 years old, the proportion diagnosed also declined from 11.3 percent in 2007 to 3.1 percent in 2011.

The number of genital warts cases also declined about 82 percent in heterosexual men under 21 years of age, and about 51 percent in men between 21 and 30 years old.

"The greatest decline in the proportion of women diagnosed as having genital warts was seen in the youngest age group (under 21 years), and all these women were eligible for the free quadrivalent human papilloma virus vaccine," the researchers wrote in their report. "A higher proportion of these women would have received the vaccine in school before becoming sexually active."

At the same time, about 12 percent of the men younger than 21 had genital warts, compared to 2.2 percent in 2007. Among 21- to 30-year-old men, the number of cases went down from 18.2 percent to 8.9 percent during the same time frame.

For men who had sex with men, the decline in genital warts cases was "modest but significant," according to the researchers. The decline was not evident in bisexual men.

There was no significant decline in HPV diagnoses for either men or women over 30 years old.

Researchers said that the decline in genital warts among the younger age groups in both genders could be from the indirect protection that the few unvaccinated individuals get from men and women who are vaccinated – a situation called herd immunity.

The authors noted that sexual health services normally target populations that are at higher risk of sexually transmitted infections.

The study, funded by CSLBiotherapies, was published online April 18 in the BMC Infectious Diseases.

Some of the authors received honoraria and research funding from CSL Biotherapies, Sanofi Pasteur MSD and Merck. One served as a site investigator for Merck and another as an advisor for Gardasil.

Reviewed by: 
Review Date: 
April 18, 2013
Last Updated:
December 11, 2013