Summary: This diversity supplement relates to aims 2 and 3 of the parent grant and proposes to examine the influence of (high and low) Human Papilloma Virus (HPV) on the risk of preterm births (PTB) and the possible immune-modulatory role of the vaginal microbiome on such relationship, considering (Black or White) race as a moderator. Aim 1 will estimate the association of HPV with PTB using logistic regression, overall and stratified by high or low risk HPV. We will test race as a moderator for each strata of HPV via an interaction term. Aim 2 will additionally use structural equations modeling to separately estimate the effects of HPV on PTB directly and/or indirectly through the microbiome and inflammation biomarkers. Findings from this study may have significant public health implications for HPV vaccination especially for women who plan to become pregnant. An association with HPV and PTB regardless of subtype may support the need for a broad-spectrum HPV vaccine, inclusive of both, high and low risk subtypes. A differential association between HPV and PTB by race within strata of HPV subtypes may suggest the need for tailored vaccine interventions. Finally understanding the predominant path in the association between HPV and PTB will provide future targets for additional research questions, potentially towards the development of clinical interventions or early diagnostic tools.