A new research study published compared medical records of vaccinated and unvaccinated girls to determine that the human papillomavirus (HPV) vaccine did not increase sexual activity amongst vaccinated young girls.
The study was conducted by Emory University and Kaiser Permanente researchers. Kaiser Permanente is a California-based managed care system.
HPV – the most sexually transmitted disease in the U.S. – usually presents no symptoms in women but can cause genital warts and cervical cancer. Research found that nearly a third of children 14 to 19 years old are infected with HPV.
However, only 34.8 percent of 13 to 17 year old girls received all three doses of the vaccine in 2011, according to the CDC.
Since 2006, public health officials have continued to suggest that 11 to 12 year old girls get the shot for HPV in order to gain maximum protection before they become sexually active.
The vaccine has been FDA approved for years now and new studies verifying its safety continue to be released.
According to a Yale University School of Medicine study, while financial and logistical matters do factor into decision-making, one of the top reasons parents choose not to vaccinate their children is that the vaccine acts as a "license for sex," as many critics have said.
New Evidence
This study, published last Monday in the Journal of Pediatrics, may provide even harder-to-dispute evidence of the falsity of that notion.
In 2006 and 2007, the research project tracked the medical signals of sexual activity of 1,398 girls ages 11 to 12. The girls were all Kaiser Permanente health plan members in Georgia. Doctors gave 493 girls at least one dose of the shot, while 905 were not given any shot.
Three years later, the researchers found no significant association between receiving the vaccine and changes in the signs of sexual behavior like contraceptive counseling, pregnancy or STD and pregnancy tests based on data like medical appointments.
Out of the girls in both groups, 90 percent did not request birth control counseling or tests for pregnancy or chlamydia. In each group, two girls became pregnant. In the unvaccinated group, three girls were diagnosed with chlamydia, and in the vaccinated group, one girl was diagnosed with chlamydia.
Lead author Robert Bednarczyk said that his study shows these results because pre-teens typically lack sexual understanding needed to comprehend the vaccine. Bednarczyk is an epidemiologist in Emory University's Hubert Department of Global Health, Rollins School of Public Health and a clinical investigator with the Kaiser Permanente Center for Health Research-Southeast.
Although there have been multiple studies about this topic, this new research is the first to move beyond the shortcomings of preceding studies because of its focus on specific signs of sexual activity. Previous work was based on self-reporting, like a Centers for Disease Control and Prevention study in January that showcases similar results to this study in women aged 15 to 24.
"We know that with sensitive topics like sexual activity, people may not be as forthcoming with researchers about their fully truthful answers," Bednarczyk said. "[Our study] is done in a much more objective manner ... So that is one of the best strengths of this particular study."
Saad Omer also thinks this study removes the informational bias present in other studies. Omer is an assistant professor at the Hubert Department of Global Health of the Emory University Rollins School of Public Health and assistant professor of the Emory Vaccine Center.
Kevin Ault, another author and associate professor of gynecology and obstetrics, said he also sees the study as the best one so far because of its utilization of signals of sexual activity and not self-reported surveys.
Hopefully, according to all three, the strength of this study will change the status quo.
The Study's Impacts
Bednarczyk has seen these public perceptions of promiscuity even before the vaccine became approved, especially since this particular vaccine targets pre-teens. That was one of the main reasons Bednarczyk and his team conducted this study, specifically focusing on this new approach with medical records.
"I'm hopeful that physicians are able to take this study and use the evidence that is presented in there in conjunction with all the other evidence about safety ... to really be able to present to parents when they are counseling them about vaccination decisions with their children," Bednarczyk said.
He hopes that the increase in evidence will pave the way for more parents to get their children vaccinated but acknowledges that it will take a while for the information to spread.
Omer said he also wishes for physicians to inform patients with this new evidence in a "proactive communication effort." At the same time, he said it was wishful thinking to believe that this study will change the minds of all parents. Instead, he said the impact would more likely be seen amongst the fence-sitting, undecided parents.
Ault said he hopes to see the HPV shot within a set of vaccines that all youth receive, including the flu shot, the meningitis shot and the whooping cough vaccine.
Moreover, Ault said he sees a broader implication with this study that he has discussed with fellow colleagues. He said people do not take riskier actions just because of preventative care or "anticipatory guidance," as he calls it, citing to studies about the effect of free condoms or abstinence education.
And this theory, according to him, applies across the medical field.
Omer also cited similar thinking about the implications of the study by using the analogy that wearing helmets does not necessarily make you take riskier actions.
"It does make you feel more safe, but it doesn't mean that you become a daredevil," Omer said. "So I am not surprised by our findings."
Bednarczyk also said he has seen mostly positive media outreach and little backlash to the study.
Limitations
Some media outlets pointed out certain imperfections in the project.
The team did not distinguish between procedural STD and pregnancy tests versus those triggered by symptoms. It also did not look into sexual signals for boys.
Bednarczyk also mentions another limitation: the study was conducted within one single manage care organization and any service external to Kaiser Permanente provided to these girls would not fall under their radar. However, he does not see that fact creating any major shift in results because there does not seem to be any reason that a vaccine would make girls more or less likely to seek care outside of the system.
Regardless of these limitations, all three researchers said they do hope this study alters the minds of apprehensive parents nationwide, leading to more protection and less presence of this disease.
The article's authors include Robert Davis, a senior investigator with the Kaiser Permanente Center for Health Research-Southeast, and Walter Orenstein, with the School of Medicine and Emory Vaccine Center.
– By Karishma Mehrotra
