Vaginal health is difficult to study in a lab setting partly because laboratory animals have totally different microbiomes than humans do.
Organs-on-a-chip mimic real bodily function, making it easier to study diseases and test drugs. In this case, the tissue acts like that of a real vagina in some important ways, responding to changes in estrogen by adjusting the expression of certain genes. It can also grow a humanlike microbiome dominated by "good" or "bad" bacteria.
https://microbiomejournal.biomedcentral.com/articles/10.1186/s40168-022-01400-1
In case science journals aren't an easy read for you, Scientific American has a good writeup on this technology.
https://www.scientificamerican.com/article/first-vagina-on-a-chip-will-help-researchers-test-drugs/