A barrier to increased 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).
HPV is a common virus, almost everyone will have it at some point in their lives, but it can cause genital warts and cervical cancer. Cervical cancer kills about 4,000 women each year. The vaccine can prevent 70 percent of problems caused by the targeted HPV strains. Because of modern distrust of medicine among anti-vaccine groups, primarily in states like California, Oregon and Washington, there have been increased concerns about pharmaceuticals in general and so only 57 percent of females between the ages of 13 and 17 have received at least one dose, whereas only 38 percent received all three recommended doses, according to the study background. Though rare, cervical cancer is still more dangerous than measles, which is getting all of the attention because of outbreaks that have occurred during the modern anti-vaccine fad.
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.
Citation: JAMA Intern Med. Published online February 9, 2015. doi:10.1001/jamainternmed.2014.7886.