Meningococcal ImmunisationPhase 4NCT05929651

Study of Immunogenicity and Safety of MenQuadfi® as a Booster Vaccine in Toddlers 12 to 23 Months, Regardless of the Quadrivalent Meningococcal Conjugate Vaccine Used for Priming in Infancy

A Phase 4 study testing MenACYW conjugate vaccine in people with Meningococcal Immunisation and Healthy Volunteers, run by Sanofi Pasteur, a Sanofi Company at 2 sites in Argentina.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

Search all trials

Trial summary

This study evaluated the immunogenicity and safety of a single dose of MenQuadfi® administered as a booster vaccine in toddlers 12 - 23 months of age in Argentina who had been primed with at least 1 dose of the quadrivalent meningococcal conjugate vaccines Nimenrix® or Menveo® during infancy to protect against… Read more about this study

Who is it for?: Ages 12 to 23 monthsHealthy volunteers can take part
Conditions the study is for: Meningococcal Immunisation, Healthy Volunteers
What is being tested?: MenACYW conjugate vaccine
Type of treatment: Vaccines, Injection or infusion
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 71 participants
Where: 2 sitesArgentina
Study dates: 7 Sep 2023to 9 Sep 2024
Phase: Phase 4
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 12 to 23 months
All sexes
Healthy volunteers accepted
Child

Who may be able to join

Aged 12 to 23 months on the day of inclusion
Participants who are healthy as determined by medical evaluation including medical history, physical examination, and judgement of the Investigator
Received at least one priming dose of licensed Nimenrix® or Menveo® vaccine during infancy before 12 months of age with an interval of at least 2 months between the last vaccination with Nimenrix® or Menveo® and the MenQuadfi® booster dose

Who cannot join

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 study (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)
Personal history of Guillain-Barré syndrome
Personal history of an Arthus-like reaction after vaccination with a tetanus toxoid containing vaccine
Known systemic hypersensitivity to any of the study intervention components, or history of a life-threatening reaction to the study intervention used in the study or to a product containing any of the same substances

Show all 12Show fewer

Moderate or severe acute illness/infection (according to investigator judgment) or febrile illness (temperature ≥ 38.0°C [≥ 100.4°F]) on the day of study intervention administration. Prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided
Receipt of any vaccine (including COVID-19 vaccines) in the 4 weeks preceding the study intervention administration or planned receipt of any vaccine (including COVID-19 vaccines) in the 4 weeks following the study intervention administration except for influenza vaccination, which may be received at least 2 weeks before or 2 weeks after the study intervention. This exception includes monovalent pandemic influenza vaccines and multivalent influenza vaccines.
Previous vaccination with a Meningococcal C vaccine or Meningococcal B (MenB) vaccine
Receipt of immunoglobulins, blood or blood-derived products in the past 3 months
Receipt of oral or injectable antibiotic therapy within 72 hours prior to the first blood draw
NOTE: The above information was not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.

Trial locations and contacts

2 sites in 1 country.

Argentina2 sites

Investigational Site Number : 0320002
Buenos Aires, Buenos Aires F.D., 1430
Investigational Site Number : 0320001
Ciudad Autonoma Buenos Aires, C1425EFD

Other trials in Argentina

About this study

Official title: A Descriptive, Phase IV, Open-label, Single-arm Multi-center Study to Assess the Immunogenicity and Safety of MenQuadfi® as a Booster Vaccine in Healthy Toddlers 12 to 23 Months of Age Who Had Been Primed With at Least 1 Dose of Another Quadrivalent Meningococcal Conjugate Vaccine, ie, Nimenrix® (MCV4-TT) or Menveo® (MCV4-CRM), in Infancy.

Participants received a single dose of MenQuadfi® at Visit 1. Participants provided 2 blood samples, one at D01 (Visit 1) pre-vaccination and another at D31 (Visit 2) post-vaccination for the immunogenicity assessments.

Study included 2 visits at D01 (Visit 1) and at D31 (Visit 2), and 1 Telephone call (TC) for safety follow-up at D09 post-study vaccination.

Read the detailed description

Study duration was approximately 30 days (+14 days) per participant

Conditions: Meningococcal Immunisation, Healthy Volunteers
Being tested: MenACYW conjugate vaccine

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

MenACYW conjugate vaccineBiological
Also called MenQuadfi®
Pharmaceutical form: Liquid solution Route of administration: Intramuscular (IM) injection

Study groups in NCT05929651
Study group	Role	What they receive
MenACYW conjugate vaccine	Experimental	participants received a single booster dose of the MenACYW conjugate vaccine with an interval of at least 2 months after the last vaccination with Nimenrix® or Menveo® received during infancy before 12 months of age Receives: Biological: MenACYW conjugate vaccine

What is being measured

The primary outcome is the main question the study is designed to answer.

Percentage of Participants With Serum Bactericidal Assay Using Human Complement (hSBA) Antibody Titers >=1:8 Against Meningococcal Serogroups A, C, Y, and W
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using human complement (hSBA). Percentages are rounded to the nearest tenth.
Measured: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Geometric Mean Titers (GMTs) Against Meningococcal Serogroups A, C, Y, and W as Measured by Serum Bactericidal Assay Using Human Complement
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using human complement (hSBA).
Measured: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Percentage of Participants With Serum Bactericidal Assay Using Human Complement Antibody Titers >=1:4 Against Meningococcal Serogroups A, C, Y, and W
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using human complement (hSBA). Percentages are rounded to the nearest tenth.
Measured: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Percentage of Participants With Serum Bactericidal Assay Using Human Complement Antibody Titers >=4-Fold Rise From Pre-vaccination to Post-Vaccination
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using human complement (hSBA). Percentages are rounded to the nearest tenth.
Measured: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Percentage of Participants With Vaccine Seroresponse by Serum Bactericidal Assay Using Human Complement
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using human complement (hSBA). hSBA vaccine seroresponse was defined for a participant with a pre-vaccination titer <1:8 as a post-vaccination titer of >=1:16 and for a participant with a pre-vaccination titer >=1:8 as a post-vaccination titer that is at least 4-fold greater than the pre-vaccination titer. Percentages are rounded to the nearest tenth.
Measured: Day 1 (pre-vaccination) and Day 31 (30 days post vaccination on Day 1)
Geometric Mean Titers Against Meningococcal Serogroups A, C, Y, and W as Measured by Serum Bactericidal Antibody Assay Using Baby Rabbit Complement (rSBA)
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using baby rabbit complement (rSBA).
Measured: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Percentage of Participants With Serum Bactericidal Antibody Assay Using Baby Rabbit Complement Antibody Titers >=1:8 and >=1:128 Against Meningococcal Serogroups A, C, Y, and W
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using baby rabbit complement (rSBA). Percentages are rounded to the nearest tenth.
Measured: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Percentage of Participants With Serum Bactericidal Antibody Assay Using Baby Rabbit Complement Antibody Titers >=4-Fold Rise From Pre-vaccination to Post-Vaccination
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using baby rabbit complement (rSBA). Percentages are rounded to the nearest tenth.
Measured: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Percentage of Participants With Vaccine Seroresponse by Serum Bactericidal Antibody Assay Using Baby Rabbit Complement
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using baby rabbit complement (rSBA). rSBA vaccine seroresponse was defined for a participant with a pre-vaccination titer <1:8 as a post-vaccination titer of >=1:32 and for a participant with a pre-vaccination titer >=1:8 as a post-vaccination titer that is at least 4-fold greater than the pre-vaccination titer. Percentages are rounded to the nearest tenth.
Measured: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Geometric Mean Concentrations (GMCs) of Antibodies Against Tetanus Toxoid
Geometric Mean Concentrations (GMCs) of anti-tetanus toxoid antibodies was measured by diphtheria, tetanus, pertussis multiplexed electrochemiluminescent assay.
Measured: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs)
An unsolicited AE was an observed AE that did not fulfill the conditions of solicited reactions, i.e., pre-listed in the CRF in terms of diagnosis and onset window post-vaccination.
Measured: Up to 30 minutes post-vaccination on Day 1
Number of Participants With Solicited Injection Site Reactions and Systemic Reactions
A solicited reaction was an "expected" adverse reaction (AR) (sign or symptom) observed and reported under the conditions (nature and onset) pre-listed in the protocol and CRF. An injection site reaction was an AR at and around the injection site. Solicited injection site reactions included injection site tenderness, injection site erythema and injection site swelling. Solicited systemic reactions included fever, vomiting, crying abnormal, drowsiness, appetite loss and irritability.
Measured: Up to 7 days post-vaccination on Day 1
Number of Participants With Unsolicited Adverse Events
An unsolicited AE was an observed AE that did not fulfill the conditions of solicited reactions, i.e., pre-listed in the CRF in terms of diagnosis and/or onset window post-vaccination.
Measured: Up to 30 days post-vaccination on Day 1
Number of Participants With Serious Adverse Events (SAEs) and Adverse Events of Special Interest (AESIs)
An SAE was any AE that at any dose resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, or was an important medical event. An AESI (serious or non-serious) was defined as one of scientific and medical concern specific to the Sponsor's study intervention or program, for which ongoing monitoring and rapid communication by the investigator to the Sponsor could be appropriate.
Measured: From vaccination (Day 1) up to 30 days post vaccination, 31 days

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

7 Sep 20239 Sep 2024

First posted3 Jul 2023
Study start7 Sep 2023
Primary completion9 Sep 2024
Study completion9 Sep 2024

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Meningococcal ImmunisationStudies of the same condition, open and under way.
More trials run by Sanofi Pasteur, a Sanofi CompanyThe sponsor's other registered studies.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 4
Primary purpose: Prevention
Allocation: Not applicable
Intervention model: Single group
Masking: None (open label)
Enrolment: 71 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05929651
Sponsor's protocol ID: MEQ00086
Other IDs: U1111-1277-6838, 2025-000002-42, 2025
Status last verified: Aug 2025
First submitted: 12 Jun 2023
Last updated: 22 Sep 2025
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: Yes
FDA-regulated device: No
Individual data sharing: Yes: 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

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

Not yet recruitingPhase 4
Single-center, Open-label Study: Immunogenicity and Safety Observation After Vaccination With ACYW135 Meningococcal Polysaccharide Vaccine in Junior High School Students Aged 13-15 Years
Meningococcal Disease; Meningococcal Meningitis
Active, not recruitingPhase 3
Study on an Investigational Quadrivalent Meningococcal Conjugate Vaccine (MenACYW Conjugate Vaccine) Administered as a 5- and/or 10-year Booster Doses in Children and Adolescents Vaccinated 5 or 10 Years Earlier as Toddlers
Meningococcal Immunisation, Healthy Volunteers
RecruitingObservational study
Post Marketing Surveillance Study for MenQuadfi® [Meningococcal (Groups A, C, Y, W) Polysaccharide Tetanus Toxoid Conjugate Vaccine] Administered in Participants Aged 6 Weeks to 55 Years in Republic of Korea
Meningococcal Immunization, Healthy Volunteers
Not yet recruitingObservational study
Metagenomic Analysis of the Pharynx in High Risk Partners
Gonorrhea, Neisseria Gonorrhea
RecruitingObservational study
Evaluation of the Antibody Persistence Beyond Five Years After Immunization With MenFiveTM (NmCV-5), a Pentavalent Meningococcal ACYWX Conjugate Vaccine
Meningoccocal Disease

All Meningococcal Immunisation trials

Study at a glance

From the registry record, last updated by the sponsor on 22 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Descriptive, Phase IV, Open-label, Single-arm Multi-center Study to Assess the Immunogenicity and Safety of MenQuadfi® as a Booster Vaccine in Healthy Toddlers 12 to 23 Months of Age Who Had Been Primed With at Least 1 Dose of Another Quadrivalent Meningococcal Conjugate Vaccine, ie, Nimenrix® (MCV4-TT) or Menveo® (MCV4-CRM), in Infancy.
ClinicalTrials.gov ID: NCT05929651
Acronym / sponsor ID: MEQ00086
Conditions: Meningococcal Immunisation, Healthy Volunteers
Phase: Phase 4
Study type: Interventional
Recruitment status: Completed
Enrolment: 71 participants (actual)
Lead sponsor: Sanofi Pasteur, a Sanofi CompanyIndustry (pharma, biotech, devices)
Study start: 7 Sep 2023 (actual)
Primary completion: 9 Sep 2024 (actual)
Study completion: 9 Sep 2024 (actual)
First posted: 3 Jul 2023 (actual)
Results: Posted 22 Sep 2025

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Study included 2 visits at D01 (Visit 1) and at D31 (Visit 2), and 1 Telephone call (TC) for safety follow-up at D09 post-study vaccination.

Detailed description

Study duration was approximately 30 days (+14 days) per participant

Study design

Primary purpose: Prevention
Allocation: Not applicable
Intervention model: Single group
Masking: None (open label)
Number of arms: 1

Arm	Type	Receives
MenACYW conjugate vaccine	Experimental	Biological: MenACYW conjugate vaccineparticipants received a single booster dose of the MenACYW conjugate vaccine with an interval of at least 2 months after the last vaccination with Nimenrix® or Menveo® received during infancy before 12 months of age

Who may qualify

Ages: 12 to 23 months
Sex: All
Healthy volunteers: Accepted
Age groups: Child

Key inclusion criteria (3 listed)

Aged 12 to 23 months on the day of inclusion
Participants who are healthy as determined by medical evaluation including medical history, physical examination, and judgement of the Investigator
Received at least one priming dose of licensed Nimenrix® or Menveo® vaccine during infancy before 12 months of age with an interval of at least 2 months between the last vaccination with Nimenrix® or Menveo® and the MenQuadfi® booster dose

Key exclusion criteria (12 listed)

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 study (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)
Personal history of Guillain-Barré syndrome
Personal history of an Arthus-like reaction after vaccination with a tetanus toxoid containing vaccine

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
MenACYW conjugate vaccineAlso: MenQuadfi®Pharmaceutical form: Liquid solution Route of administration: Intramuscular (IM) injection	Biological	MenACYW conjugate vaccine

Primary outcome

Percentage of Participants With Serum Bactericidal Assay Using Human Complement (hSBA) Antibody Titers >=1:8 Against Meningococcal Serogroups A, C, Y, and W
Time frame: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using human complement (hSBA). Percentages are rounded to the nearest tenth.
Geometric Mean Titers (GMTs) Against Meningococcal Serogroups A, C, Y, and W as Measured by Serum Bactericidal Assay Using Human Complement
Time frame: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using human complement (hSBA).
Percentage of Participants With Serum Bactericidal Assay Using Human Complement Antibody Titers >=1:4 Against Meningococcal Serogroups A, C, Y, and W
Time frame: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using human complement (hSBA). Percentages are rounded to the nearest tenth.
Percentage of Participants With Serum Bactericidal Assay Using Human Complement Antibody Titers >=4-Fold Rise From Pre-vaccination to Post-Vaccination
Time frame: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using human complement (hSBA). Percentages are rounded to the nearest tenth.
Percentage of Participants With Vaccine Seroresponse by Serum Bactericidal Assay Using Human Complement
Time frame: Day 1 (pre-vaccination) and Day 31 (30 days post vaccination on Day 1)
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using human complement (hSBA). hSBA vaccine seroresponse was defined for a participant with a pre-vaccination titer <1:8 as a post-vaccination titer of >=1:16 and for a participant with a pre-vaccination titer >=1:8 as a post-vaccination titer that is at least 4-fold greater than the pre-vaccination titer. Percentages are rounded to the nearest tenth.
Geometric Mean Titers Against Meningococcal Serogroups A, C, Y, and W as Measured by Serum Bactericidal Antibody Assay Using Baby Rabbit Complement (rSBA)
Time frame: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using baby rabbit complement (rSBA).
Percentage of Participants With Serum Bactericidal Antibody Assay Using Baby Rabbit Complement Antibody Titers >=1:8 and >=1:128 Against Meningococcal Serogroups A, C, Y, and W
Time frame: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using baby rabbit complement (rSBA). Percentages are rounded to the nearest tenth.
Percentage of Participants With Serum Bactericidal Antibody Assay Using Baby Rabbit Complement Antibody Titers >=4-Fold Rise From Pre-vaccination to Post-Vaccination
Time frame: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using baby rabbit complement (rSBA). Percentages are rounded to the nearest tenth.
Percentage of Participants With Vaccine Seroresponse by Serum Bactericidal Antibody Assay Using Baby Rabbit Complement
Time frame: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Functional meningococcal antibody activity against serogroups A, C, Y, and W was measured in a serum bactericidal assay using baby rabbit complement (rSBA). rSBA vaccine seroresponse was defined for a participant with a pre-vaccination titer <1:8 as a post-vaccination titer of >=1:32 and for a participant with a pre-vaccination titer >=1:8 as a post-vaccination titer that is at least 4-fold greater than the pre-vaccination titer. Percentages are rounded to the nearest tenth.
Geometric Mean Concentrations (GMCs) of Antibodies Against Tetanus Toxoid
Time frame: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)
Geometric Mean Concentrations (GMCs) of anti-tetanus toxoid antibodies was measured by diphtheria, tetanus, pertussis multiplexed electrochemiluminescent assay.
Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs)
Time frame: Up to 30 minutes post-vaccination on Day 1
An unsolicited AE was an observed AE that did not fulfill the conditions of solicited reactions, i.e., pre-listed in the CRF in terms of diagnosis and onset window post-vaccination.
Number of Participants With Solicited Injection Site Reactions and Systemic Reactions
Time frame: Up to 7 days post-vaccination on Day 1
A solicited reaction was an "expected" adverse reaction (AR) (sign or symptom) observed and reported under the conditions (nature and onset) pre-listed in the protocol and CRF. An injection site reaction was an AR at and around the injection site. Solicited injection site reactions included injection site tenderness, injection site erythema and injection site swelling. Solicited systemic reactions included fever, vomiting, crying abnormal, drowsiness, appetite loss and irritability.
Number of Participants With Unsolicited Adverse Events
Time frame: Up to 30 days post-vaccination on Day 1
An unsolicited AE was an observed AE that did not fulfill the conditions of solicited reactions, i.e., pre-listed in the CRF in terms of diagnosis and/or onset window post-vaccination.
Number of Participants With Serious Adverse Events (SAEs) and Adverse Events of Special Interest (AESIs)
Time frame: From vaccination (Day 1) up to 30 days post vaccination, 31 days
An SAE was any AE that at any dose resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, or was an important medical event. An AESI (serious or non-serious) was defined as one of scientific and medical concern specific to the Sponsor's study intervention or program, for which ongoing monitoring and rapid communication by the investigator to the Sponsor could be appropriate.

Results and safety

Results posted to the registry on 22 Sep 2025, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
MenACYW Conjugate Vaccine	71	68

Primary outcome: Percentage of Participants With Serum Bactericidal Assay Using Human Complement (hSBA) Antibody Titers >=1:8 Against Meningococcal Serogroups A, C, Y, and W

Time frame: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1). Number (95% Confidence Interval). Unit: Percentage of participants

Measure	MenACYW Conjugate Vaccine n = 64
Serogroup A: Day 1	72.1 (59.2 to 82.9)
Serogroup A: Day 31	100 (93.8 to 100)
Serogroup C: Day 1	60.3 (47.2 to 72.4)
Serogroup C: Day 31	100 (94.1 to 100)
Serogroup Y: Day 1	67.7 (54.7 to 79.1)
Serogroup Y: Day 31	100 (93.2 to 100)
Serogroup W: Day 1	73.4 (60.9 to 83.7)
Serogroup W: Day 31	100 (93.8 to 100)

Population analysed: The per-protocol analysis set (PPAS) was a subset of the full analysis set (FAS). The FAS included participants who received the study vaccine and had a valid post-vaccination serology result. Only participants with data collected for each specified serogroup are reported.

Primary outcome: Geometric Mean Titers (GMTs) Against Meningococcal Serogroups A, C, Y, and W as Measured by Serum Bactericidal Assay Using Human Complement

Time frame: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1). Geometric mean (95% Confidence Interval). Unit: Titer

Measure	MenACYW Conjugate Vaccine n = 64
Serogroup A: Day 1	14.0 (10.1 to 19.4)
Serogroup A: Day 31	244 (163 to 366)
Serogroup C: Day 1	12.3 (8.29 to 18.2)
Serogroup C: Day 31	1072 (805 to 1426)
Serogroup Y: Day 1	14.0 (9.70 to 20.2)
Serogroup Y: Day 31	945 (683 to 1309)
Serogroup W: Day 1	16.9 (11.8 to 24.2)
Serogroup W: Day 31	953 (712 to 1275)

Population analysed: The PPAS was a subset of the FAS. The FAS included participants who received the study vaccine and had a valid post-vaccination serology result. Only participants with data collected for each specified serogroup are reported.

Primary outcome: Percentage of Participants With Serum Bactericidal Assay Using Human Complement Antibody Titers >=1:4 Against Meningococcal Serogroups A, C, Y, and W

Time frame: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1). Number (95% Confidence Interval). Unit: Percentage of participants

Measure	MenACYW Conjugate Vaccine n = 64
Serogroup A: Day 1	96.7 (88.7 to 99.6)
Serogroup A: Day 31	100 (93.8 to 100)
Serogroup C: Day 1	76.2 (63.8 to 86.0)
Serogroup C: Day 31	100 (94.1 to 100)
Serogroup Y: Day 1	85.5 (74.2 to 93.1)
Serogroup Y: Day 31	100 (93.2 to 100)
Serogroup W: Day 1	87.5 (76.8 to 94.4)
Serogroup W: Day 31	100 (93.8 to 100)

Primary outcome: Percentage of Participants With Serum Bactericidal Assay Using Human Complement Antibody Titers >=4-Fold Rise From Pre-vaccination to Post-Vaccination

Time frame: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1). Number (95% Confidence Interval). Unit: Percentage of participants

Measure	MenACYW Conjugate Vaccine n = 59
Serogroup A	91.1 (80.4 to 97.0)
Serogroup C	100 (93.9 to 100)
Serogroup Y	96.1 (86.5 to 99.5)
Serogroup W	100 (93.7 to 100)

Adverse events

Time frame: AEs, SAEs and all-cause mortality (deaths) were collected from vaccination (Day 1) up to 30 days post vaccination, 31 days.. Other adverse events reported at 5% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
MenACYW Conjugate Vaccine	1 of 69 (1.4%)	45 of 69 (65.2%)	0 of 69

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 22 Sep 2025.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
MEQ00086 Plain Language Results SummaryLink provided by the sponsor.
Individual participant dataSharing planned: Yes. 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

Related trials for Meningococcal Immunisation

Not yet recruitingPhase 4
Single-center, Open-label Study: Immunogenicity and Safety Observation After Vaccination With ACYW135 Meningococcal Polysaccharide Vaccine in Junior High School Students Aged 13-15 Years
Meningococcal Disease; Meningococcal Meningitis
Active, not recruitingPhase 3
Study on an Investigational Quadrivalent Meningococcal Conjugate Vaccine (MenACYW Conjugate Vaccine) Administered as a 5- and/or 10-year Booster Doses in Children and Adolescents Vaccinated 5 or 10 Years Earlier as Toddlers
Meningococcal Immunisation, Healthy Volunteers
RecruitingObservational study
Post Marketing Surveillance Study for MenQuadfi® [Meningococcal (Groups A, C, Y, W) Polysaccharide Tetanus Toxoid Conjugate Vaccine] Administered in Participants Aged 6 Weeks to 55 Years in Republic of Korea
Meningococcal Immunization, Healthy Volunteers
Not yet recruitingObservational study
Metagenomic Analysis of the Pharynx in High Risk Partners
Gonorrhea, Neisseria Gonorrhea
RecruitingObservational study
Evaluation of the Antibody Persistence Beyond Five Years After Immunization With MenFiveTM (NmCV-5), a Pentavalent Meningococcal ACYWX Conjugate Vaccine
Meningoccocal Disease

Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Clinical Sciences & Operations study director

Sanofi Pasteur, a Sanofi Company

2 sites in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing MenACYW conjugate vaccine in people with Meningococcal Immunisation and Healthy Volunteers, run by Sanofi Pasteur, a Sanofi Company at 2 sites in Argentina.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 22 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in Argentina. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 22 Sep 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Percentage of Participants With Serum Bactericidal Assay Using Human Complement (hSBA) Antibody Titers >=1:8 Against Meningococcal Serogroups A, C, Y, and W (time frame: Day 1 (pre-vaccination) and Day 31 (30 days post-vaccination on Day 1)). The study lists 14 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05929651.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Sep 2025.