HPV vaccine doesn’t make girls want sex -- any more than normal

A shot that would make girls more inclined to have sex.

When the HPV vaccine came on the scene, there were some who had that fear: This shot will reduce worries about a harmful sexually transmitted infection -- and reduce girls’ inhibitions as well. And girls could mistakenly believe it’s a magic bullet against pregnancy and other sexually transmitted diseases too.

A new study kicks those fears to the curb. Researchers looked at girls who’d had an HPV vaccine and tracked the appointments they made and the advice they sought regarding sexual health over the next three years. After comparing their behaviors to girls who didn’t get the vaccine, the researchers found no increase in classic markers of sexually activity following the HPV vaccine.

But why were American parents worried in the first place that a vaccine would endanger their daughters’ virtue?

One big factor, said Robert Bednarczyk, lead author of the new study, was that the vaccine was aimed primarily at 11- and 12-year-old girls -- not, say, a 16-year-old who had admitted becoming sexually active and needed to protect herself.

In that light, it’s a reaction that shouldn’t be surprising: This is my sixth-grader you’re talking about.

“When you’re dealing with preteens and talking about sexual activity,” Bednarczyk told the Los Angeles Times in an interview Monday, “it may give people a little bit of pause. ...

“Why would you vaccinate a pre-teenager against a virus that can be contracted sexually?”

The answer is, because the vaccine works best when it precedes sexual activity.

Bednarczyk said the CDC estimated that by ages 15 to 17, more than one-quarter of the nation’s girls have reported already being sexually active. And, medical researchers have found, it’s common for the human papillomavirus to be contracted soon after sexual activity begins.

“We know that the virus is prevalent in adolescents and teenagers,” Bednarczyk said, “and young women do become sexually active.”

Bednarczyk is a clinical investigator with the Kaiser Permanente Center for Health Research-Southeast in Atlanta and an epidemiologist with Emory University. The study included 1,398 girls ages 11 and 12 from the Kaiser Permanente health plan in Georgia in 2006 and 2007 -- 493 of them had at least one dose of the HPV vaccine Gardasil; 905 girls received other vaccines but not the HPV vaccine.

For three years, researchers followed both groups to see whether they had 1) taken a pregnancy test; 2) been tested for or diagnosed with a sexually transmitted infection; or 3) sought counseling for contraceptives.

Here’s what they found: It was a wash.

There was very little difference between the two groups as far as sexual behavior -- no increase in pregnancies and no increase in sexually transmitted infections or birth-control counseling from one group to the next. You can read the study online here.

He said that the study may provide some reassurance to parents who feared a change in their daughters as a result of the vaccine.

“There have been a number of studies done that have used self-reported surveys: ‘If you received this vaccine, would it lead you to change your behaviors.”

The flaw there was relying on the girl to be honest and forthcoming about sex -- a subject about which teens are not known to be honest or forthcoming.

So this study was done to “validate those results clinically,” Bednarczyk said. “The takeaway here is that this vaccine is safe and effective, and it’s not associated with any risk of ... outcomes related to sexual activity.”

The human papillomavirus can cause cervical cancer and other, less common but serious cancers, including cancers of the vulva, vagina, penis, anus and oropharynx (back of throat including base of tongue and tonsils), according to the Centers for Disease Control and Prevention.

The CDC recommends the HPV vaccine for both girls and boys. Information about the HPV vaccine online here.