Evidence for cross-protection but not type-replacement over the 11 years after human papillomavirus vaccine introduction

• Published in: Human vaccines & immunotherapeutics Vol. 15; no. 7-8; pp. 1962 - 1969
• Main Authors: Covert, Courtney, Ding, Lili, Brown, Darron, Franco, Eduardo L., Bernstein, David I, Kahn, Jessica A.
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 03.08.2019; Taylor & Francis Group
• Subjects: Adolescent; Adult; Cross Protection; Cross-Sectional Studies; Female; Genotype; human papillomavirus; Human papillomavirus 16 - genetics; Human papillomavirus 16 - immunology; Humans; Immunity, Herd; Logistic Models; Odds Ratio; Papillomavirus Infections - epidemiology; Papillomavirus Infections - prevention & control; Papillomavirus Vaccines - immunology; Prevalence; Research Paper; Time Factors; type-replacement; United States - epidemiology; Vaccination - statistics & numerical data; Young Adult; United States; Cross-protection; human papillomavirus; type-replacement
• ISSN: 2164-5515; 2164-554X
• DOI: 10.1080/21645515.2018.1564438

Examination of cross-protection and type replacement after human papillomavirus (HPV) vaccine introduction is essential to guide vaccination recommendations and policies. The aims of this study were to examine trends in non-vaccine-type HPV: 1) genetically related to vaccine types (to assess for cross-protection) and 2) genetically unrelated to vaccine types (to assess for type replacement), among young women 13-26 years of age during the 11 years after HPV vaccine introduction. Participants were recruited from a hospital-based teen health center and a community health department for four cross-sectional surveillance studies between 2006 and 2017. Participants completed a survey that assessed sociodemographic characteristics and behaviors, and cervicovaginal swabs were collected and tested for 36 HPV genotypes. We determined changes in proportions of non-vaccine-type HPV prevalence and conducted logistic regression to determine the odds of infection across the surveillance studies, propensity-score adjusted to control for selection bias. Analyses were stratified by vaccination status. Among vaccinated women who received only the 4-valent vaccine (n = 1,540), the adjusted prevalence of HPV types genetically related to HPV16 decreased significantly by 45.8% (adjusted odds ratio [AOR] = 0.48, 95% confidence interval [CI] = 0.31-0.74) from 2006-2017, demonstrating evidence of cross-protection. The adjusted prevalence of HPV types genetically related to HPV18 did not change significantly (14.2% decrease, AOR = 0.83, 95% CI = 0.56-1.21). The adjusted prevalence of HPV types genetically unrelated to vaccine types did not change significantly (4.2% increase, AOR = 1.09, CI = 0.80-1.48), demonstrating no evidence of type replacement. Further studies are needed to monitor for cross-protection and possible type replacement after introduction of the 9-valent HPV vaccine.