U-M study: HPV risk doesn’t depend on teen’s sexual activity

Finding supports controversial recommendation to vaccinate all women aged 11-26

A teen’s sexual activity doesn’t predict her future risk for HPV, and shouldn’t determine whether she receives the HPV vaccine, according to University of Michigan researchers.

The U of M study conducted by C.S. Mott Children’s Hospital’s Child Health Evaluation and Research Unit found that the sexual activity of adolescents did not predict future contraction of HPV as adults. HPV, genital human papillomavirus, is the most common sexually transmitted infection, according to the Centers for Disease Control and Prevention.

The findings support the CDC’s recommendation for universal vaccination for all women ages 11 to 26, regardless of sexual experience, Dr. Amanda Dempsey, the study’s lead researcher, told Michigan Messenger. 

“We couldn’t find any discernible adolescent behavior, including sexual activity, that was associated with an increased risk of HPV infection as a sexually active young adult,” Dempsey said. “HPV is so prevalent that everyone who becomes sexually active is at risk.”

Continued -Dempsey says she and her colleagues undertook the study because of a continued “reluctance among parents to be okay with vaccinating their younger female adolescent children. In clinic, I hear some parents expressing that their adolescent child wouldn’t need the vaccine because she’s not at risk. We wanted to examine more closely a girl’s risk for HPV during adolescence based on her behaviors.”

They also wanted to address conflicting recommendations about who should get the vaccine, Dempsey said. While the CDC recommends it for all women age 11 to 26, the American Cancer Society recommends that women 18 and older talk with their doctors about whether they’re at risk for the virus based on their sexual history.

The problem with that approach, the study results indicate, is that “you really can’t pick out one or two behaviors that predict if you’ve been exposed to HPV,” Dempsey said. “HPV is just so common and so easily transmitted from person to person that it doesn’t take more than one partner to get exposed. It doesn’t matter what you did as an adolescent. Most people are going to become sexually active and at that point are going to be at risk.”

The prospective study — one that relies on information gathered at the time of a person’s life being studied rather than asking participants to remember information retrospectively — examined data on 3,181 adolescents who participated in a long-term study. Researchers were able to use data collected on participants from early adolescence on to link their HPV status with the behaviors the girls reported several years earlier. 

The U of M researchers found no correlation between an adult woman’s HPV infection and her number of sexual partners, her history of having an older male sexual partners and/or a new sex partner with the past year, her illegal drug use, her history of sex while alcohol-impaired or her regular use of cigarettes or alcohol.

HPV infection generally occurs shortly after a woman becomes sexually active. Most women never know they have the virus because it usually goes away on its own and may not cause any symptoms.

The HPV vaccine guards against four types of HPV: two that cause 70 out of 100 cases of cervical cancer and two that cause 90 out of 100 cases of genital warts. There are more than 100 types of HPV, but only some types lead to cervical cancer or genital warts.

Because the vaccine protects against only four strains, even women who have tested positive for HPV should still get vaccinated, Dempsey said. 

The study appears in the July issue of Pediatrics.