Epidemiologic evaluation of human papillomavirus type competition in unvaccinated women from Xiamen, China.

Background: Human papillomavirus (HPV) vaccination is expected to reduce the burden of cervical cancer and other HPV-related diseases. However, if competition exists among HPV types, type replacement may occur following the reduction of vaccine-targeted types. Here, we conducted the study to explore natural HPV type competition in unvaccinated women. Methods: HPV DNA test results from cervical samples collected between January 2013 and July 2023 at Xiamen University's Women and Children's Hospital were analyzed. In cross-sectional study, first-visit HPV genotyping results were used, and logistic regression model was constructed to evaluate interactions between vaccine-targeted and other HPV types. In cohort of women with multiple visits, the risk of acquiring other HPV types was compared between women infected with vaccine-targeted types and those HPV-negative using Cox proportional hazards model. Results: Among 159,049 women, 19.8% tested HPV-positive, with 5.1% having multiple types. Significant negative associations were observed between HPV-6 and HPV-72 (OR: < 0.01; 95%CI: < 0.01-0.03), HPV-18 and HPV-72 (OR: < 0.01; 95%CI: < 0.01-0.02), HPV-31 and HPV-83 (OR: < 0.01; 95%CI: < 0.01-0.55), HPV-33 and HPV-26 (OR: < 0.01; 95%CI: < 0.01-0.81), HPV-45 and HPV-55 (OR: < 0.01; 95%CI: < 0.01- < 0.01), HPV-56 and HPV-26 (OR: < 0.01; 95%CI: < 0.01-0.09), as well as HPV-59 and HPV-69 (OR: < 0.01; 95%CI: < 0.01-0.68), suggesting potential type competition. However, no type competition pair was found in the cohort study. Conversely, women with vaccine-targeted types had a higher risk of acquiring other types (HR > 1.0). Conclusions: Our findings suggested that HPV-6 and HPV-72, HPV-18 and HPV-72, HPV-31 and HPV-83, HPV-33 and HPV-26, HPV-45 and HPV-55, HPV-56 and HPV-26, HPV-59 and HPV-69 were potential type competition pairs.