Back during primary season, I got a little hot and bothered when some candidates made some crazy claims about the Human Papillomavirus (HPV) vaccine. Those claims were, of course, completely unfounded. But I acknowledged that the reason that some are potentially opposed to the HPV vaccine in adolescent girls is that they believe that it sends an implicit signal to those girls that the sexual activity through which they might acquire HPV is permissible. In other words, they believe that if you give girls the vaccine, it might make them more likely to have sex.
That’s an answerable question. Many of the studies that have looked at this in the past were flawed. But in a recent study in Pediatrics, researchers sought to answer this question in a more robust way. “Sexual Activity-Related Outcomes After Human Papillomavirus Vaccination of 11- to 12-Year-Olds”
OBJECTIVE: Previous surveys on hypothesized sexual activity changes after human papillomavirus (HPV) vaccination may be subject to self-response biases. To date, no studies measured clinical markers of sexual activity after HPV vaccination. This study evaluated sexual activity-related clinical outcomes after adolescent vaccination.
METHODS: We conducted a retrospective cohort study utilizing longitudinal electronic data from a large managed care organization. Girls enrolled in the managed care organization, aged 11 through 12 years between July 2006 and December 2007, were classified by adolescent vaccine (HPV; tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis, adsorbed; quadrivalent meningococcal conjugate) receipt. Outcomes (pregnancy/sexually transmitted infection testing or diagnosis; contraceptive counseling) were assessed through December 31, 2010, providing up to 3 years of follow-up. Incidence rate ratios comparing vaccination categories were estimated with multivariate Poisson regression, adjusting for health care-seeking behavior and demographic characteristics.
They looked at 1398 girls, of whom 493 received the HPV vaccine and 905 did not. Then they looked at the pregnancy rates among those two groups, as well as pregnancy testing rates. They also looked at the rates for sexually transmitted infection testing and actual disease. And they looked at reported contraceptive counseling And what did they find? There were no significant differences in these occurances between girls who received an HPV vaccine and those who did not.
Here’s that in a chart:
Do you see a difference? Me neither. There’s no association between an adolescent girl getting the HPV vaccine and her engaging in sexual activity. Since there’s a definite benefit, and the harm seems to be mostly mythical, giving this should be a no-brainer.
[Cross-posted at The Incidental Economist]