Bertoli HK, et al. - Researchers analyzed 26 studies studies published between 1986 and 2017 in PubMed, Embase and Cochrane Library, to determine the overall and type-specific prevalence of human papillomavirus (HPV) and p16 overexpression in vaginal cancer and vaginal intraepithelial neoplasia (VaIN). These studies used PCR-based or Hybrid Capture 2 tests and/or any method. They estimated the pooled prevalence of HPV and p16 overexpression along with 95% confidence intervals (CIs) by using a random effects model. For vaginal squamous cell carcinoma (VaSCC, n=593) and VaIN (n=1374), 66.7% and 85.2%, respectively, were the pooled HPV prevalences estimated. Heterogeneity was observed. Among the HPV positive VaSCC and VaIN cases, the most predominant HPV type was HPV16, followed by HPV33, and HPV45 (in VaIN) and HPV18, and HPV33 (in VaSCC). p16 overexpression was seen in 89.9% of HPV positive and 38.9% of HPV negative vaginal cancers in pooled analyses. Overall, a substantial proportion of vaginal neoplasia might be prevented through vaccination against HPV.