Study on Immunogenicity and Safety of a Meningococcal ACYW Conjugate Vaccine in Healthy Infants and Toddlers

Inclusion Criteria:

• Aged 6 to 7 months on the day of inclusion

• Participants who are healthy as determined by medical evaluation including medicalhistory, physical examination and judgment of the Investigator

Exclusion Criteria: Participants are excluded from the study if any of the following criteria apply:

• Known or suspected congenital or acquired immunodeficiency; or receipt ofimmunosuppressive 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 3months

• History of meningococcal infection, confirmed either clinically, serologically, ormicrobiologically

• At high risk for meningococcal infection during the study (specifically but notlimited to participants with persistent complement deficiency, with anatomic orfunctional asplenia, or participants traveling to countries with high endemic orepidemic disease)

• Personal history of Guillain-Barré syndrome

• Personal history of an Arthus-like reaction after vaccination with a tetanustoxoid-containing vaccine

• Known systemic hypersensitivity to any of the study intervention components, orhistory of a life-threatening reaction to the study intervention(s) used in thestudy or to a product containing any of the same substances

• Moderate or severe acute illness/infection (according to investigator judgment) orfebrile illness (temperature ≥ 38.0°C [≥ 100.4°F]) on the day of study interventionadministration. A prospective participant should not be included in the study untilthe condition has resolved or the febrile event has subsided

• Receipt of any vaccine (including COVID-19) and Meningococcal B vaccines) in the 4weeks preceding the first and second study intervention administration or plannedreceipt of any vaccine (including COVID-19 and Meningococcal B vaccines) in the 4weeks following any study intervention administration except for influenzavaccination, which may be received at least 2 weeks before or 2 weeks after thestudy interventions. This exception includes monovalent pandemic influenza vaccinesand multivalent influenza vaccines.

• Previous vaccination against meningococcal A, C, W, or Y disease with either thetrial vaccine or another vaccine (i.e., mono- or quadrivalent meningococcalconjugate vaccine) containing serogroups A, C, Y, or W.