Effect of Prophylactic Human Papillomavirus (HPV) Vaccination on Oral HPV Infections Among Young Adults in the United States

Abstract

Purpose The incidence of human papilloma virus (HPV)-positive oropharyngeal cancers has risen rapidly in recent decades among men in the United States. We investigated the US population-level effect of prophylactic HPV vaccination on the burden of oral HPV infection, the principal cause of HPV-positive oropharyngeal cancers. Methods We conducted a cross-sectional study of men and women 18 to 33 years of age (N = 2,627) within the National Health and Nutrition Examination Survey 2011 to 2014, a representative sample of the US population. Oral HPV infection with vaccine types 16, 18, 6, or 11 was compared by HPV vaccination status, as measured by self-reported receipt of at least one dose of the HPV vaccine. Analyses accounted for the complex sampling design and were adjusted for age, sex, and race. Statistical significance was assessed using a quasi-score test. Results Between 2011 and 2014, 18.3% of the US population 18 to 33 years of age reported receipt of at least one dose of the HPV vaccine before the age of 26 years (29.2% in women and 6.9% in men; P < .001). The prevalence of oral HPV16/18/6/11 infections was significantly reduced in vaccinated versus unvaccinated individuals (0.11% v 1.61%; P_adj = .008), corresponding to an estimated 88.2% (95% CI, 5.7% to 98.5%) reduction in prevalence after model adjustment for age, sex, and race. Notably, the prevalence of oral HPV16/18/6/11 infections was significantly reduced in vaccinated versus unvaccinated men (0.0% v 2.13%; P_adj = .007). Accounting for vaccine uptake, the population-level effect of HPV vaccination on the burden of oral HPV16/18/6/11 infections was 17.0% overall, 25.0% in women, and 6.9% in men. Conclusion HPV vaccination was associated with reduction in vaccine-type oral HPV prevalence among young US adults. However, because of low vaccine uptake, the population-level effect was modest overall and particularly low in men.

Fig 1.

Effect of human papillomavirus (HPV) vaccination on the burden of vaccine-type oral HPV infections in the US population of individuals 18 to 33 years of age, National Health and Nutrition Examination Survey 2011 to 2014. The bar graph shows the estimated effect of prophylactic HPV vaccination on the burden of vaccine-type oral HPV infections (HPV16/18/6/11) among individuals 18 to 33 years of age at participation in the National Health and Nutrition Examination Survey 2011 to 2014. Results are shown overall as well as separately in men and women. Results are presented as the total number of infections in the absence of HPV vaccination in the US population: (US population size × prevalence in unvaccinated) = blue bars; the number of preventable infections at 100% vaccination levels (US population size × prevalence in vaccinated) = gold bars; and the number of potentially vaccine-prevented infections at current HPV vaccine–uptake levels (US population size of vaccinated individuals × prevalence difference between unvaccinated and vaccinated) = gray bars. As a measure of the population-level effect of HPV vaccination on the burden of oral HPV infection, we estimated the proportion of potentially vaccine-prevented infections at the current HPV vaccine–uptake levels (number of potentially vaccine-prevented infections/total number of infections in the absence of HPV vaccination). Prevalence estimates used for these computations were not adjusted for any factors. The prevalence of individual vaccine-type HPV infections in the US population of individuals 18 to 33 years of age was as follows: HPV16 = 0.79%, HPV18 = 0.20%, HPV6 = 0.29%, and HPV11 = 0.14%.

Fig A1.

Inclusions/exclusions for the analyses of the effect of human papilloma virus (HPV) vaccination on oral HPV infections, National Health and Nutrition Examination Survey (NHANES) 2011 to 2014. MEC, Mobile Exam Center. ACASI, Audio-computer assisted self-interview.