Immunogenicity and Safety of a Booster Dose of an Investigational Quadrivalent Meningococcal Conjugate Vaccine

Healthy adolescents and adults who had received 1 dose of a quadrivalent meningococcal
conjugate vaccine 4 to 10 years previously will be randomized to receive either 1 dose of
MenACYW conjugate vaccine or a licensed MCV4 . All participants will undergo immunogenicity
assessment at baseline (pre-vaccination) and 1 month post-vaccination and will also be
evaluated for safety up to Day 180 post-vaccination. In addition, a subset will have an
additional blood sample collected at 6 days post-vaccination for immunogenicity assessment.

Inclusion Criteria:

- Aged ≥ 15 years on the day of inclusion

- Subject has documented record of having received 1 dose of a quadrivalent
meningococcal conjugate vaccine 4 to 10 years prior to enrollment

- Subject aged 15 to < 18 years: assent form signed and dated by the subject and
informed consent form (ICF) signed and dated by the parent or guardian

- Subject aged ≥ 18 years: ICF signed and dated by the subject

- Subjects aged 15 to < 18 years: both the subject and parent / guardian are able to
attend all scheduled visits and to comply with all trial procedures

- Subjects aged ≥ 18 years: able to attend all scheduled visits and to comply with all
trial procedures

Exclusion Criteria:

- Subject is pregnant, lactating, or of childbearing potential (to be considered of
non-childbearing potential, a female must be pre-menarche or post-menopausal for at
least 1 year, surgically sterile, or using an effective method of contraception or
abstinence from at least 4 weeks prior to vaccination until at least 4 weeks after
vaccination)

- 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 Day 30 visit except for influenza vaccination,
which may be received at least 2 weeks before study investigational vaccines. This
exception includes monovalent pandemic influenza vaccines and multivalent influenza
vaccines

- Previous vaccination against meningococcal disease with either an investigational or
approved meningococcal B vaccine

- 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)

- History of meningococcal infection, confirmed either clinically, serologically, or
microbiologically

- At high risk for meningococcal infection during the trial (specifically, but not
limited to, subjects with persistent complement deficiency, with anatomic or
functional asplenia, or subjects 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 vaccine(s) used in the trial or to a vaccine
containing any of the same substances

- Personal history of an Arthus-like reaction after vaccination with a tetanus
toxoid-containing vaccine

- Personal history of Guillain-Barré syndrome

- Verbal report of thrombocytopenia, contraindicating intramuscular vaccination in the
Investigator's opinion

- Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion,
contraindicating intramuscular vaccination in the Investigator's opinion

- Deprived of freedom by an administrative or court order, or in an emergency setting,
or hospitalized involuntarily

- Current alcohol abuse or drug addiction

- 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 the Investigator's judgment)
on the day of vaccination or febrile illness (temperature ≥ 100.4°F). A prospective
subject should not be included in the study until the condition has resolved or the
febrile event has 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.