HPV vaccination not associated with increase in sexually transmitted infections

A barrier to human papillomavirus (HPV) vaccination has been the concern that it may promote unsafe sexual activity, but a new study of adolescent girls finds that HPV vaccination was not associated with increases in sexually transmitted infections (STIs), according to an article published online by JAMA Internal Medicine.

Nearly one-quarter of U.S. females between the ages 14 and 19 and 45 percent of women between the ages of 20 and 24 are affected by HPV. The HPV vaccination can prevent cervical, vulvar and vaginal cancers and genital warts caused by certain HPV strains. Still, HPV vaccination rates remain low in the United States and, by 2013, only 57 percent of females between the ages of 13 and 17 had received at least one dose, whereas only 38 percent had received all three recommended doses, according to the study background.

Anupam B. Jena, M.D., Ph.D., of Harvard Medical School, Boston, and coauthors used a large insurance database of females (ages 12 to 18) from 2005 through 2010 to examine STIs among girls who were vaccinated and those who were not.

The authors found use of the vaccination increased over time with 27.3 percent of females receiving the vaccination by the end of 2010 compared with just 2.5 percent of females at the end of 2006. The study included 21,610 females who were vaccinated against HPV and 186,501 matched females who were nonvaccinated.

The study found that females who were vaccinated were more likely to be sexually active in the year before vaccination compared with those who were nonvaccinated. Study results also indicate that vaccinated females had higher rates of STIs before and after vaccination compared with those who were nonvaccinated. For example, the rates of STIs in the year before vaccination were higher among HPV-vaccinated females (94 of 21,610, 4.3 per 1,000) compared with nonvaccinated females (522 of 186,501, 2.8 per 1,000). The rates of STIs increased both for vaccinated (147 of 21,610, 6.8 per 1,000) and nonvaccinated (781 of 186,501, 4.2 per 1,000) girls in the year after vaccination. The difference in odds between the two groups implies that the HPV vaccination was not associated with an increase in STIs relative to the growth of STIs among nonvaccinated females.

"We found no evidence that HPV vaccination leads to higher rates of STIs. Given low rates of HPV vaccination among adolescent females in the United States, our findings should be reassuring to physicians, parents and policy makers that HPV vaccination is unlikely to promote unsafe sexual activity," the study concludes.

(JAMA Intern Med. Published online February 9, 2015. doi:10.1001/jamainternmed.2014.7886. Available pre-embargo to the media at http://media.jamanetwork.com.)

Editor's Note: This study was funded by a grant from the National Institutes of Health and a grant from the National Institute of Aging. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

In a related commentary, Robert A. Bednarczyk, Ph.D., of Emory University, Atlanta, writes: "However, just as we do not wait until we have been in the sun for two hours to apply sunscreen, we should not wait until after an individual is sexually active to attempt to prevent HPV infection."

"The hesitancy on the part of parents and physicians to vaccinate or discuss vaccination may be attributable to worries that HPV vaccination will be seen as a tacit approval for sexual activity. ... In this issue of JAMA Internal Medicine, Jena et al add to the literature by presenting a novel analysis that indicates no evidence for increased sexual activity after HPV vaccination," he continues.

"These findings should not come as a surprise to researchers in the field of HPV vaccinology and should serve as continued reassurance that HPV vaccination does not lead to sexual disinhibition. However, this reassurance leaves us with the question, "How can we use these findings to address concerns of anxious parents of adolescents? ... To date, much research has been conducted to identify HPV vaccination barriers, but less research has been conducted to identify the preferred content and mode of delivery of information to mitigate these barriers. Addressing this knowledge gap through the development and delivery of information relative to all key partners (adolescents, their parents and their health care professionals) will be critical in removing the stigma of HPV vaccine in our efforts to fully use this vaccine," Bednarczyk concludes.

(JAMA Intern Med. Published online February 9, 2015. doi:10.1001/jamainternmed.2014.7894. Available pre-embargo to the media at http://media.jamanetwork.com.)

Editor's Note: The author made conflict of interest disclosures. The commentary was supported in part by a grant from the National Institutes of Health. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

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Media Advisory: To contact author Anupam B. Jena, M.D., Ph.D., call David Cameron at 617-432-0441 or email david_cameron@hms.harvard.edu. To contact commentary author Robert A. Bednarczyk, Ph.D., call Melva Robertson at 404-727-5692 or email melva.robertson@emory.edu.