Primary Objective:

To demonstrate the vaccine seroresponse sufficiency of meningococcal serogroups A, C, Y, and W following the administration of a booster dose of meningococcal Polysaccharide (Serogroups A, C, Y and W) Tetanus Toxoid (MenACYW) Conjugate vaccine:

• In Group 1 participants who were first vaccinated with 1 dose of MenACYW Conjugate vaccine 3-6 years before the booster dose.
• In Group 2 participants who were first vaccinated with 1 dose of Menveo vaccine (meningococcal [Groups A, C, Y and W135] Oligosaccharide Diphtheria CRM197 Conjugate vaccine) 3-6 years before the booster dose.

Secondary Objective:

To describe:

• The vaccine seroresponse, seroprotection (serum bactericidal assay using human complement [hSBA] titer greater than or equal to [>=]1:8), and antibody responses (geometric mean titers [GMTs]) of meningococcal serogroups A, C, Y, and W measured using hSBA in serum specimens collected 6 days (±1 day) after vaccination in a subset of 50 participants per group (Groups 1 and 2).
• The vaccine seroresponse, seroprotection (hSBA titer >=1:8), and antibody responses (GMTs) to serogroups A, C, Y, and W measured using hSBA on Day (D)0 (pre-vaccination) and D30 (+14 days) after vaccination with MenACYW Conjugate vaccine alone (Groups 1 and 2).
• The antibody persistence (GMTs and vaccine seroprotection; hSBA titer >=1:8) of meningococcal serogroups A, C, Y, and W before a booster dose in participants who received either MenACYW Conjugate vaccine or Menveo vaccine 3-6 years earlier.
• The antibody persistence (GMTs and vaccine seroprotection; hSBA titer >=1:8) of meningococcal serogroups A, C, Y, and W in participants who received either a single dose MenACYW Conjugate vaccine (participants randomized to MET59 Groups 1, 3, and 4) or Menveo vaccine (participants assigned to MET59 Group 2), as part of study MET50, or MET43 (participants randomized to MET59 Groups 1, 3 and 4).
• To describe the vaccine seroresponse, seroprotection (hSBA titer >=1:8), and antibody responses (GMTs) to the antigens present in MenACYW Conjugate vaccine, when MenACYW Conjugate vaccine was given concomitantly with meningococcal serogroup B (MenB) vaccine (Groups 3 and 4), compared to those when it was given alone (Group 1).

Study duration per participant was approximately 6 months including: 1 day of screening and vaccination, 1 or 2 additional visits at Day 6 and Day 30, 2 phone calls and a safety follow-up/end of study visit, at Day 8 and Day 180 after vaccine administration, respectively.

Safety assessment included solicited reactions within 7 days after vaccination, unsolicited adverse events (AEs) up to 30 days after vaccination, serious adverse events (SAEs) throughout the study.

Inclusion criteria :

• Aged >= 13 to less than (<) 26 years on the day of inclusion.
• Participants participated in and completed study MET50 (MET50 Groups 1, 2, or 3 only) or study MET43 (MET43 Groups 1, 2, or 3 only).
• For MET59 Group 2 only (Menveo vaccine-primed participants only; enrichment population): participants had a documented record of having received 1 dose of Menveo vaccine 3-6 years earlier either as part of a clinical trial or as routine vaccination. Participants who participated in MET50 Group 4 can be enrolled if they fulfill this criterion.
• Participants aged 13 to < 18 years: assent form had been signed and dated by the participant and informed consent form (ICF) had been signed and dated by the parent or guardian.
• Participants aged >=18 (or legal age of majority, if different from 18 years of age) to < 26 years: ICF had been signed and dated by the participants.
• Participant aged 13 to < 18 years: both the participant and parent or guardian were able to attend all scheduled visits and complied with all trial procedures.
• Participants aged >=18 (or legal age of majority, if different from 18 years of age) to < 26 years: able to attend all scheduled visits and complied with all trial procedures.

Exclusion criteria:

• Participant was 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 4 weeks 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 in the 4 weeks preceding the 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 (28 days) preceding the trial vaccination or planned receipt of any vaccine before Visit 3 (Day 30) except for influenza vaccination, which might be received at least 2 weeks before study investigational vaccine.
• Receipt of immune globulins, blood or blood-derived products in the past 3 months.
• Receipt of any meningococcal vaccine including a licensed or investigational MenACWY vaccine or MenB vaccine since participation in study MET50 or MET43.
• Menveo vaccine-primed participants only (enrichment group for Group 2): receipt of more than 1 dose of Menveo vaccine or vaccination with another licensed or investigational MenACWY vaccine or with a licensed or investigational MenB vaccine.
• 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).
• History of meningococcal infection, confirmed either clinically, serologically, or microbiologically.
• At high risk for meningococcal infection during the trial (specifically but not limited to participants with persistent complement deficiency, with anatomic or functional asplenia, or participants travelling to countries with high endemic or epidemic disease).
• Known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccines used in the trial or to a vaccine containing any of the same substances.
• Personal history of Guillain-Barré syndrome.
• Personal history of an Arthus-like reaction after vaccination with a tetanus toxoid-containing vaccine within at least 10 years of the proposed study vaccination.
• Verbal report of thrombocytopenia, contraindicating IM vaccination.
• Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating IM vaccination.
• Current alcohol abuse or drug addiction.
• Chronic illness (e.g., Human immunodeficiency viruses, hepatitis B, hepatitis C) that, in the opinion of the investigator, was 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 >= 100.4 degree Fahrenheit). A prospective participant should not be included in the study until the condition had resolved or the febrile event had subsided.
• Receipt of oral or injectable antibiotic therapy within 72 hours prior to the first blood draw.
• 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 (i.e, parent, spouse, natural or adopted child) of the Investigator or employee with direct involvement in the proposed study.

The above information was not intended to contain all considerations relevant to a participant'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

The laboratory personnel who performed the serology testing were blinded to the group assignment.