This fellowship will build on previous experience and expertise of bacterial vaginosis (BV) at MITU and NIMR. It is based on secondary analyses of data from previous studies and the testing and analysis of stored specimens. Data and specimens from the EDCTP-funded Women’s health Project (WHP), the MRC-funded Inflammation Sub-study, and the MDP 301 feasibility study will be used to carry out in-depth analyses of the correlates of (BV) and recurrence, description and correlates of BV-specific bacteria, and description of immune responses associated with BV or BV-specific bacteria. In addition, the Vaginal Gene-Expression and Microbiome (VGEM) project will use 217 stored cervicovaginal lavages from WHP participants attending their 12 month (final) visit, of which over 50% were diagnosed with BV Samples will be sequenced using 16S methods to characterise the microbiome, and then tested for human gene expression.