A Study to Investigate the Safety and Immunogenicity of the Quadrivalent Influenza mRNA Vaccines in Adults Aged 18 Years and Above

Inclusion Criteria: - Aged from 18 years on the day of inclusion or aged from 21 years on the days of inclusion, depending on the countries.

• A female participant is eligible to participate if she is not pregnant orbreastfeeding and one of the following conditions applies:

• Is of non-childbearing potential. To be considered of non-childbearingpotential, a female must be postmenopausal for at least 1 year, or surgicallysterile OR

• Is of childbearing potential and agrees to use an effective contraceptivemethod or abstinence from at least 4 weeks prior to study interventionadministration until at least 12 weeks after study intervention administration.

• A female participant of childbearing potential must have a negative highly sensitivepregnancy test (urine or serum as required by local regulation) within 8 hours

before the 1st dose of study intervention Exclusion Criteria: Participants areexcluded 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 the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3months)

• Known systemic hypersensitivity to any of the study intervention components (eg,polyethylene glycol, polysorbate); history of a life-threatening reaction to thestudy interventions used in the study or to a product containing any of the samesubstances; any allergic reaction (eg, anaphylaxis) after administration of mRNAvaccine

• Previous history of myocarditis, pericarditis, and / or myopericarditis

• Known history of previous episodes of Gillian-Barre Syndrome (GBS), neuritis (including Bell's palsy), convulsions, encephalitis, transverse myelitis, andvasculitis

• Participants with an ECG that is consistent with possible myocarditis orpericarditis or, in the opinion of the investigator, demonstrates clinicallyrelevant abnormalities that may affect participant safety or study results

• Self-reported thrombocytopenia, contraindicating Intramuscular vaccination based onInvestigator's judgment

• Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion,contraindicating Intramuscular vaccination based on Investigator's judgment

• Chronic illness that, in the opinion of the Investigator, is at a stage where itmight interfere with study conduct or completion

• Moderate or severe acute illness / infection (according to Investigator's judgment)or febrile illness (temperature ≥ 38.0°C [≥ 100.4°F]) on the day of vaccination. Aprospective participant should not be included in the study until the condition hasresolved or the febrile event has subsided

• Participant who had acute infection symptoms or a positive SARS-CoV-2 RT-PCR orantigen test in the past 10 days prior to the 1st visit (V01)

• Receipt of any vaccine in the 4 weeks preceding study intervention administration orplanned receipt of any vaccine in the 4 weeks following study interventionadministration

• Receipt of immune globulins, blood or blood-derived products in the past 3 months

• Previous vaccination against influenza in the previous 6 months with aninvestigational or marketed vaccine

• Receipt of any mRNA vaccine/product in the 2 months preceding study interventionadministration NOTE: The above information is not intended to contain allconsiderations relevant to a patient's potential participation in a clinical trial.