Not Yet RecruitingPhase 3

Immunogenicity and Safety Study of an Investigational Quadrivalent Meningococcal Conjugate Vaccine Administered in Healthy Infants and Toddlers in China

4,568 participantsStarted 2026-08-20

Plain-language summary

The purpose of this study is to describe the safety and immunogenicity of MenACYW conjugate vaccine compared with locally-licensed meningococcal vaccines in healthy infants and toddlers in China. Study details include: * Study duration (including 6-month safety follow-up after the last dose): - Cohort I (Groups 1 and 2): approximately 211 or 271 days (approximately 7 or 9 months) - Cohort II (Groups 3 and 4): up to 18 months - Cohort III (Groups 5 and 6): up to 21 months - Cohort III (Group 7): approximately 16 months * Vaccination Visits Period: * Cohort I (Groups 1 and 2): a 2-dose vaccination at V01 (D01) and V02 (D31) or V03 (D91). Two blood samples are collected pre-vaccination (D01) and 30 days post the 2nd dose of vaccination (D61 or D121). Telephone calls (TCs) are planned on the 4th, the 9th, and the 21st day after each vaccination, and 5 TCs (1 TC/month) are planned for the 5 months post the last on-site visit for safety follow-up. For participants receiving the second vaccination with a 3-month interval: an on-site visit is planned 30 days post the 1st dose of vaccination (V02, D31) for participant diary collection. * Cohort II (Groups 3 and 4): a 2-dose vaccination at V01 (D01) and V02 (D31) or V03 (D91). A 1-dose booster is planned for Group 3 only at 18 MoA (within the 18th month from the participant's birth date). Up to 4 blood samples will be collected. In the primary vaccination period, blood samples are collected before the first primary vaccination (D01) and 30 days post the 2nd dose of primary vaccination (D61 or D121). A blood sample will be collected from all participants at 18 MoA. A post-booster blood sample will be collected from participants in Group 3, 30 days post their booster vaccination. Telephone calls are planned on the 4th, the 9th, and the 21st day after each vaccination (including the booster dose), and 5 TCs (1 TC/month) are planned for the 5 months post the last on-site visit of the primary and the booster vaccination periods, respectively, for safety follow-up. For participants receiving the second vaccination with a 3-month interval: an on-site visit is planned 30 days post the 1st dose of vaccination (V02, D31) for participant diary collection. - Cohort III - Groups 5 and 6: a 3-dose primary vaccination at V01 (D01), V02 (D31) and V03 (D61), a 1-dose booster at 12 MoA (within the 12th months from the participant's birth date) on V05 or at 18 MoA (within the 18th months from the participant's birth date) on V06. In total 4 blood samples are to be collected. In the primary vaccination period, blood samples are to be collected before the first primary vaccination (D01) and 30 days post the 3rd dose of primary vaccination (D91); in the booster vaccination period, blood samples are to be collected before booster vaccination at V05 (for participants receiving the booster at 12 MoA) or V06 (for participants receiving the booster at 18 MoA), and 30 days post booster vaccination (V05 + 30 days or V06 + 30 days). Telephone calls are planned on the 4th, the 9th, and the 21st day after each vaccination (including the booster dose), and 5 TCs (1 TC/month) are planned for the 5 months post the last on-site visit of the primary and the booster vaccination periods respectively for safety follow-up. \- Cohort III - Group 7: a 3-dose primary vaccination at V01 (D01), V02 (D61) and V03 (D121), a 1-dose booster at V05 at 12 MoA (within the 12th months from the participant's birth date). In total 4 blood samples are to be collected. In the primary vaccination period, blood samples are to be collected before the first primary vaccination (D01) and 30 days post the 3rd dose of primary vaccination (D151); in the booster vaccination period, blood samples are to be collected before booster vaccination at V05 and 30 days post booster vaccination (V06). Telephone calls are planned on the 4th, the 9th, and the 21st day after each vaccination (including the booster dose), and 5 TCs (1 TC/month) are planned for the 5 months post the last on-site visit of the primary and the booster vaccination periods (ie, V04 and V06), respectively, for safety follow-up. A safety visit is planned on the 9th day after the first vaccination for the ESDR participants (the first 30 participants in this group).

Who can participate

Age range

2 Months – 23 Months

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * For Cohort I: Aged 12 months through 23 months on the day of inclusion. For Cohort II: Aged 6 months through 11 months on the day of inclusion. For Cohort III: Aged 2 months through 5 months on the day of inclusion - Born at full term of pregnancy (≥37 weeks) or born after a gestation period of 27 through 36 weeks and medically stable as assessed by the investigator - Informed consent form has been signed and dated by the parent(s) or other LAR (and by an independent witness if required by local regulations). - Participant and parent/LAR are able to attend all scheduled visits and to comply with all study procedures. Exclusion Criteria: * Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy; or long-term systemic corticosteroid therapy - History of meningococcal infection - History of any neurological disorders - History of Guillain-Barré syndrome - History of an Arthus-type hypersensitivity reaction after a previous dose of tetanus toxoid-containing vaccine - At high risk for meningococcal infection during the study - Known systemic hypersensitivity to any of the study intervention components, or history of a life-threatening reaction to the study interventions used in the study or to a product containing any of the same substances - Self-reported thrombocytopenia, contraindicating intramuscular injection - Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Participants 12 through 23 MoA (Cohort I): Vaccine seroresponse to meningococcal serogroups A, C, Y, and W

Timeframe: 30 days post 2nd vaccination (up to Day 121)

Participants 12 through 23 MoA (Cohort I): Antibody titers (in terms of GMTs) against meningococcal serogroups A, C, Y, and W measured by rSBA

Timeframe: 30 days post 2nd vaccination (up to Day 121)

Participants 6 through 11 MoA (Cohort II): Vaccine seroresponse to meningococcal serogroups A, C, Y, and W

Timeframe: 30 days post 2nd vaccination (up to Day 121)

Participants 6 through 11 MoA (Cohort II): Antibody titers (in terms of GMTs) against meningococcal serogroups A, C, Y, and W, measured by rSBA

Timeframe: 30 days post 2nd vaccination (up to Day 121)

Participants 3 through 5 MoA (Cohort III -Groups 5 and 6): Vaccine seroresponse to meningococcal serogroups A, C, Y, and W

Timeframe: Day 91

Participants 3 through 5 MoA (Cohort III -Groups 5 and 6): Antibody titers (in terms of GMTs) against meningococcal serogroups A, C, Y, and W, measured by rSBA

Timeframe: Day 91

Trial details

NCT IDNCT07710872

SponsorSanofi

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2028-03-13

Contact for this trial

Trial Transparency email recommended (Toll free for US & Canada)

800-633-1610 Contact-US@sanofi.com

View on ClinicalTrials.gov More Meningococcal Infection trials

Plain-language summary

Who can participate

Age range

2 Months – 23 Months

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

What they're measuring

Participants 12 through 23 MoA (Cohort I): Vaccine seroresponse to meningococcal serogroups A, C, Y, and W

Timeframe: 30 days post 2nd vaccination (up to Day 121)

Participants 12 through 23 MoA (Cohort I): Antibody titers (in terms of GMTs) against meningococcal serogroups A, C, Y, and W measured by rSBA

Timeframe: 30 days post 2nd vaccination (up to Day 121)

Participants 6 through 11 MoA (Cohort II): Vaccine seroresponse to meningococcal serogroups A, C, Y, and W

Timeframe: 30 days post 2nd vaccination (up to Day 121)

Participants 6 through 11 MoA (Cohort II): Antibody titers (in terms of GMTs) against meningococcal serogroups A, C, Y, and W, measured by rSBA

Timeframe: 30 days post 2nd vaccination (up to Day 121)

Participants 3 through 5 MoA (Cohort III -Groups 5 and 6): Vaccine seroresponse to meningococcal serogroups A, C, Y, and W

Timeframe: Day 91

Participants 3 through 5 MoA (Cohort III -Groups 5 and 6): Antibody titers (in terms of GMTs) against meningococcal serogroups A, C, Y, and W, measured by rSBA

Timeframe: Day 91