Decline In Genital Warts Among Australian Women After Vaccination: Study

Researchers from Australia have reported a fall in the cases of genital warts in young girls. The decline has been attributed to the implementation of human papillomavirus (HPV) vaccination program in 2007.

The vaccine program was aimed at children between the ages 12 and 13. These children were again given a catch-up vaccine shot when they were 13-18 years old and 18-26 years old. The vaccine protected against HPV strains that cause genital warts and even cancer.

Preliminary data from the study showed that there was a 59 percent reduction in the number of women between 12 and 26 who were diagnosed with HPV. During the same time, a significant decrease was recorded in the number of women under 18 years of age who had developed cervical abnormalities.

The study was based on a sample size of 85,770 people in Australia between 2004 and 2011. Researchers divided data into the pre-vaccination period (2004-2007) and the vaccination period (2007-2011). The study also categorized people based on age groups; those under 21, 21-30 year olds, and those 30 and older.

Dramatic reduction in HPV cases were seen in women who were under ages 21; from being around 11 percent in 2007 to 0.85 percent (total of 13 cases) in the year 2011.

A similar pattern of decline in HPV cases were seen across age groups and in both men and women.

"The mathematical modelers told us that a large decline was to be expected, but we tend not to believe it until we see it. We were particularly surprised to see a 93 percent drop in genital warts in young women when only 85 percent were vaccinated. This suggests that the herd immunity that is protecting men is, in turn, also protecting unvaccinated women," said Basil Donovan, an author of the study and a professor at the University of New South Wales in Sydney, reports The New York Times.

The study is published in the journal bmj.                                                                                                

The human papillomaviruses are the most common viruses that cause genital warts. According to estimates by the Centers for Disease Control and Prevention, about 11,967 new cases of HPV-associated cervical cancer are diagnosed in the United States each year. The agency recommends the HPV vaccination for all pre-teen girls and boys aged 11 to 12.

A recent study published in the journal Pediatrics reported that two out of every five parents in the U.S. are against the HPV vaccination for their daughters.