A vaccine against inflammatory acne has been tested successfully in mice, but it is not certain that it would work similarly in humans.^[78]

A 2007 microbiology article reporting the first genome sequencing of a Propionibacterium acnes bacteriophage (PA6) said this “should greatly enhance the development of a potential bacteriophage therapy to treat acne and therefore overcome the significant problems associated with long-term antibiotic therapy and bacterial resistance.”^[79]

Talarozole, a retinoic acid metabolism blocking agent, is currently under investigation for acne therapy in combination with tretinoin.^{[citation needed]}