Study to Evaluate Safety, Efficacy and Immunogenicity of Acne mRNA Vaccine in Adults With Moderate to Severe Acne

Inclusion Criteria:

* Participants who are overtly healthy as determined by medical evaluation including medical history, physical examination, and laboratory tests as judged by the investigator
* Clinical diagnosis of moderate or severe facial acne vulgaris with Investigator's Global Assessment (IGA) score of Moderate or Severe (grade 3 or grade 4 on the 5-grade IGA scale) and ≥ 25 non-inflammatory lesions (ie, open and closed comedones) and ≥ 20 inflammatory lesions (ie, papules and pustules) and ≤ 2 nodulocystic lesions (ie, nodules and cysts)

Exclusion Criteria:

Participants are excluded from the study if any of the following criteria apply:

* Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within 6 months prior to the first study intervention administration; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months)
* Known systemic hypersensitivity to any of the study intervention components; history of a life-threatening reaction to the study interventions used in the study or to a product containing any of the same substances; any allergic reaction (eg, anaphylaxis) after administration of mRNA coronavirus disease 2019 (COVID-19) vaccine
* Active nodulocystic acne, acne conglobate, acne fulminans, secondary acne (eg, chloracne, drug-induced acne) or other forms of acne (eg, acne mechanica)
* Use of any acne-affecting treatment without an appropriate washout period
* Receipt of any vaccine (other than the study vaccine) in the 4 weeks preceding any study intervention administration or planned receipt of any vaccine (other than the study vaccine) in the 4 weeks following any study intervention administration
* Previous vaccination against C. acnes with an investigational vaccine
* Receipt of immune globulins, blood or blood-derived products in the past 3 months
* Self-reported or documented seropositivity for human immunodeficiency virus (HIV), hepatitis B virus, or hepatitis C virus.

The above information is not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.