Chlamydiae are a type of endoparasite living in eukaryotes and they belong to the prokaryotes,which have a unique developmental cycle. It spreads all over the world,and infects across different species to cause multiple diseases with complicated symptoms,thus the diagnosis can be challenging. Therefore,it is needed to seek for an effective vaccine to enhance immunity for the prevention of chlamydia infection. In this article,we focuse on the subunit vaccine and new strategies,which intro...