Presentation Abstract

Abstract Number: 844
Presentation Title: Comparison of HPV prevalence between HPV-vaccinated and non-vaccinated young adult women (20-26 years)
Presentation Time: Sunday, Apr 19, 2015, 1:00 PM - 5:00 PM
Location: Section 35
Poster Board Number: 16
Author Block: Fangjian Guo, Jacqueline M. Hirth, Abbey B. Berenson. University of Texas Medical Branch, Galveston, TX
Abstract Body: Background Although the HPV vaccine provides protection against genital warts and HPV-associated anogenital cancers among young girls, there is some concern about its effectiveness when administered to young adult women due to the risk of prior HPV infections before vaccination and potentially reduced immunogenicity when administered at older ages. This study used 2 cycles of the National Health and Nutrition Examination Survey (NHANES) data to evaluate the effectiveness of the HPV vaccine among women 20-26 years of age.
Methods This cross-sectional study included 592 young adult women (20-26 years) with complete information on HPV prevalence and HPV vaccination status from NHANES 2007-2010. Multivariate logistic regression models were used to examine differences in HPV prevalence between vaccinated and unvaccinated young women.
Results After controlling for past sexual behaviors, vaccinated women had a lower risk of testing positive for the 4 types included in the HPV vaccine (6, 11, 16, or 18; Table 1). This association became stronger when the number of recent sexual partners was controlled for. However, vaccinated women had a higher prevalence of nonvaccine high-risk types than unvaccinated women (61.5% vs 39.7%, prevalence ratio 1.55, 95% CI 1.22-1.98). After adjusting for the number of recent sexual partners, the difference in prevalence of high-risk nonvaccine types was reduced, but remained significant.
Conclusion HPV vaccination was effective for the protection against all four vaccine types in young adult women. Vaccinated women had a higher prevalence of nonvaccine
high-risk types, which suggests that they may benefit from vaccines that cover additional types of HPV.
Table 1. Type-specific HPV prevalence among US adult women by HPV vaccination status.
Prevalence (95% CI) aAdjusted Prevalence Ratio (95% CI) Vaccinated vs. Unvaccinated
Vaccinated (n=80)Unvaccinated (n=512)Model 1 bModel 2 cModel 3 d
Any HPV70.7 (59.1-82.3)56.1 (50.2-62.0)1.26(1.05-1.52)1.28(1.05-1.55)1.24(1.02-1.52)1.21(0.99-1.48)
Low-Risk Type41.6 (30.4-52.8)40.3 (34.0-46.5)1.03(0.77-1.38)1.06(0.76-1.47)1.03(0.72-1.45)0.96(0.68-1.37)
High-Risk Type63.6 (51.4-75.7)44.5 (39.1-49.9)1.43(1.14-1.79)1.34(1.07-1.69)1.30(1.06-1.60)1.26(1.03-1.53)
HPV 6, 11, 16 or 1810.8 (2.2-19.4)19.7 (15.8-23.7)0.55(0.26-1.15)0.48(0.23-1.01)0.46(0.22-0.93)0.42(0.21-0.87)
HPV 6 or 1105.6 (3.5-7.7)0
HPV 16 or 1810.8 (2.2-19.4)15.9 (12.1-19.7)0.68(0.32-1.45)0.57(0.27-1.21)0.54(0.26-1.12)0.51(0.25-1.04)
Nonvaccine Type68.6 (57.1-80.2)53.9 (47.9-60.0)1.27(1.05-1.54)1.28(1.05-1.57)1.25(1.02-1.54)1.21(0.98-1.48)
Nonvaccine Low-Risk Type41.6 (30.4-52.8)38.1 (31.9-44.4)1.09(0.81-1.46)1.11(0.79-1.56)1.08(0.76-1.55)1.02(0.71-1.47)
Nonvaccine High-Risk Type61.5 (49.4-73.7)39.7 (34.7-44.7)1.55(1.22-1.98)1.47(1.15-1.88)1.43(1.14-1.79)1.38(1.11-1.71)
a: Prevalence was weighted using sample weights.
b: Model 1 was adjusted for age, race/ethnicity, education, income, smoking status, and marital status.
c: Model 2 was adjusted for variables in Model 1 plus sexually transmitted diseases and number of lifetime sexual partners.
d: Model 3 was adjusted for variables in Model 2 plus number of sexual partners in the past 12 months.