Study of Different Formulations of Vaccines Encoding the RSV Monovalent Antigen or the Flu H5 Antigen in Participants 18 to 49 Years of Age

Inclusion Criteria: * Aged 18 to 49 years on the day of inclusion * A female participant is eligible to participate if she is not pregnant or breastfeeding and of the following conditions applies: * Is of NCBP (Non-Child-Bearing Potential). To be considered of NCBP, a female must be post-menopausal for at least 1 year, or surgically sterile. OR * Is of CBP (Child-Bearing Potential) and uses an effective contraceptive method or abstinence from at least 4 weeks prior to study intervention administration until at least 12 weeks after the last study intervention administration. Exclusion Criteria: • Any condition which, in the opinion of the Investigator, might interfere with the evaluation of the study objectives The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.