The most common sexually transmitted infection (STI) is genital human papillomavirus (also called HPV). Most people who become infected with HPV do not even know they have it, so it is easily spread. The 40 or so varieties of the virus (it is completely different from herpes or HIV) are passed on through genital contact. The virus can produce genital warts and raises the risk of cervical and other cancers.

The human papillomavirus vaccine is generally seen as important to preventing the disease and its spread, but it can be a touchy topic for parents, who may be reluctant to have their preteen vaccinated against a sexually transmitted infection, fearing that the vaccine could encourage promiscuous sexual behavior or earlier initiation of sexual activity.

Hopefully, these findings will reassure the physicians who are counseling parents making decisions about vaccinations for their child.

A number of surveys have been done to try to address parents' concerns about the vaccine, and young girls have indicated that receiving the vaccine would not lead to changes in their sexual behavior or encourage them to become sexually active. Because the surveys were typically self-reported, bias was possible, Robert Bednarczyk, an epidemiologist at the Rollins School of Public Health at Emory University in Atlanta, told TheDoctor.

“[Another] of the major [drawbacks] is that these surveys were usually conducted in older adolescents or young adults, and the concern we have seen is about the recommendation to vaccinate 11- and 12-year olds,” said Bednarczyk, who is also a clinical investigator at Kaiser Permanente Center for Health Research.

So Bednarczyk and his colleagues at Kaiser Permanente and Emory University used the medical visit information in the Kaiser Permanente Georgia research infrastructure to monitor outcomes related to sexual activity in 1,398 11- and 12-year old girls, 493 of whom received the HPV vaccine and 905 who did not. “This way, we could take an objective look [at the HPV vaccine and it its relation to sexual activity among preteens] and not have the limitations of the self-reported survey,” said Bednarczyk.

The investigators looked at the outcomes typically associated with sexual activity --lab testing for a sexually transmitted disease or pregnancy, diagnosis of STI or counseling about the use of contraceptives. With up to three years of follow-up of these girls, no difference in these outcomes was seen between the girls who received the HPV vaccine versus those who did not.

“These findings just keep adding to the evidence that that the HPV vaccine does not impact sexual activity,” Bednarczyk said.

Physicians should be able to use the information presented in the current study and other reported research efforts to provide solid evidence to parents that the HPV vaccine is safe and effective and not associated with increased or earlier sexual activity, Bednarczyk said. “It is an important vaccine to prevent cervical cancer in women and other cancers of the genital tract, and also to protect against genital warts.”

Bednarczyk thinks the next step is to make sure that this information reaches physicians and parents; hopefully, it will reassure the physicians who are counseling those making decisions about vaccinations for their child.

“We also need to look at the best way to get this message out,” he added. The information should be accurate and presented in a way that is going to be easily understood by parents and preteens, and sensitive to the topic being discussed.

The study was published online in the journal Pediatrics.