The primary objectives of this study are:

• To describe the safety profile of each of the investigational vaccine formulations for all participants
• To describe the humoral and cell-mediated immune responses to all of the investigational vaccine formulations
• To evaluate the dose response to vaccine components
• To describe the magnitude, quality, and longevity of immune responses to each of the investigational vaccine formulations

Study duration per participant is approximately 1 year, which will include a safety follow-up contact at 12 months after vaccination

Inclusion criteria :

• Individuals born in Canada and vaccinated with a combination vaccine in accordance with the National Immunization Program (NIP).
• Aged ≥ 19 years and < 22 years on the day of inclusion.
• Able to attend all scheduled visits and to comply with all trial procedures.

Exclusion criteria:

• Pregnant, or lactating, or of childbearing potential and not using an effective method of contraception or abstinence from at least 4 weeks prior to the first vaccination until at least 3 months after the last vaccination. To be considered of non-childbearing potential, a female must be pre-menarche, or post-menopausal for at least 1 year, or surgically sterile.
• Participation at the time of study enrollment (or in the 4 weeks preceding the first trial vaccination) or planned participation during the present trial period in another clinical trial investigating a vaccine, drug, medical device, or medical procedure.
• Receipt of any vaccine in the 4 weeks preceding the first trial vaccination or planned receipt of any vaccine in the 4 weeks before and/or after any study vaccination except for influenza vaccination only, which may be received at least 2 weeks before or 2 weeks after any study vaccination.
• History of autoimmune disorder.
• History of cardiovascular disorder.
• History of Guillain-Barré syndrome.
• Receipt of immune globulins, blood or blood-derived products in the past 3 months.
• Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive 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 3 months).
• Known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccine(s) used in the trial or to a vaccine containing any of the same substances.
• Laboratory-confirmed/self-reported thrombocytopenia, contraindicating intramuscular vaccination.
• Bleeding disorder or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating intramuscular vaccination.
• Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with trial conduct or completion.
• Moderate or severe acute illness/infection (according to investigator judgment) on the day of vaccination or febrile illness (temperature ≥ 38.0 C). A prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided.
• Identified as an Investigator or employee of the Investigator or study center with direct involvement in the proposed study, or identified as an immediate family member (ie, parent, spouse, natural or adopted child) of the Investigator or employee with direct involvement in the proposed study.

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

Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org