Receipt of HPV Vaccine Associated with Increased Prevalence of High-Risk HPV Infections

Identifying possible negative side effects of vaccines helps to determine whether benefits outweigh the costs of a medical intervention that claims to prevent a disease. Such a cost-benefit analysis is essential both for vaccine policy as well as informed consent. This study seeks to determine whether the use of the human papillomavirus (HPV) vaccine is related to an increase in high-risk (HR), possibly cancer related, HPV infections. Data from the U.S. National Health and Examination Nutrition Survey reveal a statistically significantly higher percentage of women who received an HPV vaccine carried an HR-HPV than women who did not receive an HPV shot (Rao-Scott Chi-square contrast p-value of 0.002). Vaccine recipients tested positive less frequently for HPVs targeted by the vaccines, but had a higher prevalence of other HR (cancer related) HPVs. The results suggest that a thorough investigation of the effects of HPV vaccines on HR-HPV viruses (and other pathogens) not targeted by them is warranted.