The introduction of a vaccine against the human papillomavirus (HPV) in 2006 has reduced the prevalence of the cancer-causing virus among U.S. teenage girls by 56 percent, according to a new study from the U.S. Centers for Disease Control and Prevention (CDC).

Illustrative image. (Source: Internet)

According to the CDC, human papillomavirus, the most common sexually transmitted infection in the United States, can cause genital warts, cervical cancer and throat cancer.

"This report shows that HPV vaccine works well, and the report should be a wake-up call to our nation to protect the next generation by increasing HPV vaccination rates," said CDC Director Tom Frieden in a statement.

The study used data from the National Health and Nutrition Examination Survey to compare the proportion of girls and women aged 14 to 59 years with certain types of HPV in the four-year period before and after the vaccine program began.

As expected from clinical trials before the vaccine was licensed, the study showed that the vaccine is highly effective.

"The decline in vaccine type prevalence is higher than expected and could be due to factors such as to herd immunity, high effectiveness with less than a complete three-dose series and/or changes in sexual behavior we could not measure," said lead author Lauri Markowitz.

"This decline is encouraging, given the substantial health and economic burden of HPV-associated disease," Markowitz said.

In the United States, HPV vaccines are recommended for 11- or 12-year-old boys and girls, and they are given in three shots over six months. But the CDC said only one third of U.S. girls aged 13 to 17 have been fully vaccinated against HPV.

Currently, about 79 million Americans, most in their late teens and early 20s, are infected with HPV, and each year about 14 million people become newly infected, the CDC said.

According to the CDC, HPV infections cause about 19,000 cancers each year among women in the United States, with cervical cancer being the most common. HPV infections also cause about 8,000 cancers each year in the U.S. men, with throat cancers being the most common.

Source: Xinhuanet