Acne vaccine: Experimental shot for common skin condition reaches clinical trials. Here's what you need to know.

A close-up image of the side profile of a woman's face. She has severe facial acne. .

Scientists are testing a vaccine to treat acne, a skin condition that affects around 95% of people between the ages of 11 and 30. If the shot makes it through trials, it could become the first-ever acne vaccine.

Acne is an inflammatory disorder in which hair follicles and pores in the skin become clogged and the body reacts, leading to the formation of pimples that most commonly appear across the face, upper arms, trunk and back. The condition can have numerous triggers, including a sensitivity to certain body-made hormones, especially those that shift in adolescence; taking specific medications; and carrying certain genetic factors. Bacteria on the skin, such as the species Cutibacterium acnes, can also contribute to acne.