Study of an Investigational Quadrivalent Meningococcal Conjugate Vaccine Administered in Children Aged 2 to 9 Years

Healthy participants will be enrolled, randomized, and will receive a single dose of either
MenACYW conjugate vaccine or MENVEO®.

All participants will be assessed for immunogenicity at baseline (pre-vaccination) and at
Visit 2 (post-vaccination). Safety information will be collected post each vaccination and
throughout the entire study.

Inclusion Criteria:

- Aged 2 to 9 years on the day of inclusion

- Assent form has been signed and dated by the participant (as required by local
regulations) and informed consent form (ICF) has been signed and dated by parent(s) or
guardian

- Participant and parent/guardian are able to attend all scheduled visits and to comply
with all trial procedures

Exclusion Criteria:

- Participant is pregnant, or lactating, or of childbearing potential and not using an
effective method of contraception or abstinence from at least 4 weeks prior to
vaccination until at least 4 weeks after vaccination. To be considered of
non-childbearing potential, a female must be pre-menarche

- 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 prior to Visit 2 except for influenza vaccination,
which may be received at least 2 weeks before or after the study investigational
vaccines. This exception includes monovalent, multivalent, live, and attenuated
influenza vaccines

- Previous vaccination against meningococcal disease with either the trial vaccine or
another vaccine (ie., mono- or polyvalent, polysaccharide, or conjugate meningococcal
vaccine containing serogroups A, C, Y, W; or meningococcal B serogroup containing
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, participants with persistent complement deficiency, with anatomic or
functional asplenia, or participants traveling 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

- Verbal report of thrombocytopenia, contraindicating intramuscular vaccination by the
Investigator's judgment

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

- Personal history of Guillain-Barré syndrome

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

- 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's judgment) on
the day of vaccination or febrile illness (temperature ≥100.4°F). A prospective
participant 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 a natural or adopted child of the Investigator or employee with direct
involvement in the proposed study