December 10, 2014 — Administering the human papillomavirus vaccine to young girls does not lead to an increase in risky sexual activity, according to a McGill University study published in the Canadian Medical Association Journal, Reuters reports (Doyle, Reuters, 12/8).
According to CDC, 79 million U.S. residents have HPV, the most common sexually transmitted infection in the country, and there are 14 million new cases each year. The virus has been linked to cervical, vaginal, penile and anal cancers. The number of girls receiving the full dosage of the human papillomavirus vaccine increased by about four percentage points between 2012 and 2013, but the overall rate remains well short of CDC's 80% vaccination goal, according to research from the agency (Women's Health Policy Report, 11/3).
All eighth-grade girls in Ontario, Canada, were offered the full three-dose regimen of the HPV vaccine beginning in 2007, Reuters reports. For the study, the researchers used Ontario health databases to examine more than 128,000 girls, 50% of whom were eligible to receive the vaccine at school. The remaining half had completed the eighth grade before the vaccine was offered in school.
Study Results, Impact
The study found that more than 10,000 girls in grades 10 through 12 became pregnant and 6,000 contracted an STI. However, the researchers found that teenage girls who were vaccinated for HPV were no more likely to contract a STI or become pregnant than those who were unvaccinated.
According to Reuters, one other study has been conducted on the issue. The research had a small sample size and also found no connection. McGill University's Leah Smith, the lead author of the new study, said, "Our study was almost 200 times larger than the previous study and found no evidence of an increase in risk."
Further, Smith noted that previous "studies on HPV vaccination and sexual behavior have focused on perceptions of changes in sexual behavior following vaccination, rather than actual behavior, or have relied on self-reports of sexual behavior, which are notoriously problematic to study because they are vulnerable to the recall bias, response bias, and social desirability bias." She noted that the new study's results "should help put any remaining uncertainty on this issue to rest" (Reuters, 12/8).