HPV Vaccination Does Not Increase Sexual Activity Among Teens, Study Finds

October 15, 2012 — Teens who are vaccinated against the human papillomavirus are not more likely than non-vaccinated teens to engage in sexual behavior, according to a study published Monday in the journal Pediatrics, the AP/Sacramento Bee reports.

The American Academy of Pediatrics and CDC recommend that girls and boys begin the three-dose vaccination series at age 11 or 12 (Tanner, AP/Sacramento Bee, 10/14). The vaccine is most effective when it is administered before a person's first sexual encounter.

Although HPV is the most common sexually transmitted infection in the U.S. and can cause cancers of the cervix, anus and throat, vaccination rates have remained relatively low, possibly because of parental concerns that vaccinating against an STI will make teens less concerned about engaging in sexual activity (O'Connor, "Well," New York Times, 10/15).

Study Details

The researchers examined medical records for 1,398 girls enrolled in Kaiser Permanente Georgia -- an Atlanta-area managed care organization -- who visited their primary care physician at age 11 or 12 in 2006 and 2007. Of those, 493 received at least one dose of the HPV vaccine during the study period (Pittman, Reuters, 10/15).

The researchers compared three years of medical records for vaccinated and unvaccinated girls to determine whether they sought contraception advice, testing for STI or pregnancy, or became pregnant.

Outcomes in both groups were largely the same. At least 90% of both groups did not seek pregnancy or STI testing, or contraceptive counseling. Two girls in each group became pregnant, while one vaccinated girl and three unvaccinated girls were diagnosed with chlamydia.

Implications

Previous studies on connections between HPV vaccination and sexual behavior involved self-reporting, which is less reliable than the method used in the new study (AP/Sacramento Bee, 10/14). However, the researchers were unable to determine whether STI and pregnancy tests were distributed as part of standard clinical procedures or because girls reported being sexually active or having symptoms.

Divya Patel, an ob-gyn at the University of Michigan who was not involved in the study, also noted that the girls may not have been aware of the connection between the vaccine and an STI and that they could have obtained pregnancy and STI tests from someone other than their PCP. She suggests that future studies focus on older teens and various locations, such as school health clinics (Reuters, 10/15).