Discussion
Our substudy, which included South African and Kenyan women enrolled in the ECHO TrialIn light of the negative effect of Cu-IUD use on the relative abundance and prevalence of various lactobacilli, we sought to elucidate if this effect was mediated by CuWe employed an integrative approach to identify microbial and immunological differences between HIV cases and controls, finding that the absolute abundance of The implications of our findings regarding highly effective and available contraceptives provide key insights into shifts in the vaginal environment that may follow contraceptive initiation. However, limitations of the study include the duration of longitudinal data, small sample sizes of some CST groups, and the lack of a control/placebo arm in the Trial. While we appreciate the ethical constraints of offering a placebo to participants seeking safe and effective contraception, we also appreciate the limitation that this places on our ability to assess the effect of these contraceptive options. However, despite the lack of a true control group, we feel that the randomized nature of the trial and the inclusion of pre-post analyses have enabled our results to have some generalizability and offer valuable insights. In a move to expand the contraceptives available to women in settings with a high unmet need for contraception, use of a Cu-IUD has many benefits including long-term efficacy (up to 5 years), a non-hormonal mechanism of action, and typically does not require regular clinical visits. However, our randomized data confirm the observations of others