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 includingmedical history, physical examination, and laboratory tests as judged by theinvestigator

• Clinical diagnosis of moderate or severe facial acne vulgaris with Investigator'sGlobal 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 nodulocysticlesions (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 ofimmunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy,within 6 months prior to the first study intervention administration; or long-termsystemic corticosteroid therapy (prednisone or equivalent for more than 2consecutive weeks within the past 3 months)

• Known systemic hypersensitivity to any of the study intervention components (eg,polyethylene glycol [PEG], polysorbate); history of a life-threatening reaction tothe study interventions used in the study or to a product containing any of the samesubstances; any allergic reaction (eg, anaphylaxis) after administration of mRNAcoronavirus 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 anystudy intervention administration or planned receipt of any vaccine (other than thestudy 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.