Phase 3 Completed N=447 Prevention

Study on a MenACYW Conjugate Vaccine Administered as a Single Dose in Participants Aged 12 Months and Older in Vietnam

Meningococcal Infection · Healthy Volunteers

Source: ClinicalTrials.gov NCT06228586 ↗

Enrolled (actual)

447

Serious AEs

1.1%

Results posted

Sep 2025

Primary outcomePrimary: Geometric Mean Titers (GMTs) of Antibodies Against Meningococcal Serogroups A, C, Y, and W — 4.44; 7.58; 39.0; 43.2 titer

◆ Published Evidence

No publication linked

No peer-reviewed publication reporting this trial's results has been linked yet. This can indicate results are unpublished — a known publication-bias signal. We re-check periodically.

Summary

The MEQ00074 study was a Phase III, open-label, single-center study aimed at describing the immunogenicity and safety of a single dose of investigational quadrivalent Meningococcal Polysaccharide (serogroups A, C, W, and Y) Tetanus Toxoid Conjugate Vaccine (MenACYW conjugate vaccine) in participants aged 12 months and older in Vietnam. The primary objectives of the study were: * To describe the antibody responses to meningococcal serogroups A, C, W, and Y before and 30 days after the administration of a single dose of MenACYW conjugate vaccine * To describe the safety profile of a single dose of MenACYW conjugate vaccine The duration of each participant's participation will be approximately 30 to 44 days.

Outcome Measures

Outcome	Result	p-value
PRIMARY Geometric Mean Titers (GMTs) of Antibodies Against Meningococcal Serogroups A, C, Y, and W	4.44; 7.58; 39.0; 43.2; 2.61; 5.65	—
PRIMARY Percentage of Participants With Serum Bactericidal Assay Using Human Complement Titers >=4-Fold Rise From Pre-Vaccination to Post-Vaccination	81.5; 66.5; 99.5; 97.7; 96.5; 95.5	—
PRIMARY Percentage of Participants With Serum Bactericidal Assay Using Human Complement Titers >=1:4 and >=1:8	79.5; 94.1; 25.0; 59.7; 97.5; 89.1	—
PRIMARY Percentage of Participants With Serum Bactericidal Assay Using Human Complement Vaccine Seroresponse for Serogroups A, C, Y, and W	81.5; 66.5; 99.5; 97.7; 96.5; 95.5	—
PRIMARY Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs)	0; 1	—
PRIMARY Number of Participants With Solicited Injection Site Reactions and Systemic Reactions	29; 29; 34; 24	—
PRIMARY Number of Participants With Unsolicited Non-Serious Adverse Events	48; 11	—
PRIMARY Number of Participants With Serious Adverse Events (SAEs) and Adverse Events of Special Interest (AESIs)	3; 2; 0; 0	—

Eligibility Criteria

Inclusion Criteria

Aged 12 months and above on the day of inclusion

Adults:

Aged 18 and above on the day of inclusion
A female participant was eligible to participate if she was not pregnant or breastfeeding and one of the following conditions applies:
Was of non-childbearing potential. To be considered of non-childbearing potential, a female must be pre-menarche or post-menopausal for at least 1 year, or surgically sterile.
OR Was of childbearing potential and agreed to use an effective contraceptive method or abstinence from at least 4 weeks prior to study intervention administration until at least 4 weeks after study intervention administration.

A female participant of childbearing potential would have a negative highly sensitive pregnancy test (urine) within 1 week before the dose of study intervention.

Informed consent form was signed and dated
Was able to attend all scheduled visits and to comply with all study procedures

Adolescents:

Aged 10 to 17 years on the day of inclusion
A female participant was eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies:
Was of non-childbearing potential. To be considered of non-childbearing potential, a female must be pre-menarche.
OR Was of childbearing potential and agrees to use an effective contraceptive method or abstinence from at least 4 weeks prior to study intervention administration until at least 4 weeks after study intervention administration.

A female participant of childbearing potential would have a negative highly sensitive pregnancy test (urine) within 1 week before the dose of study intervention.

Informed consent form was signed and dated by both the participant and the parent(s) or another legally acceptable representative and by an independent witness, if required by local regulations Assent form was signed and dated by the participant (assent form required for participants aged 12 to 15 years) or verbal consent was obtained (for participants aged 10 to 11 years), and informed consent form was signed and dated by the parent(s) or another legally acceptable representative and by an independent witness, if required by local regulations
Participant and parent/legally acceptable representative were able to attend all scheduled visits and to comply with all study procedures

Children:

Aged 2 to 9 years on the day of inclusion
Verbal consent was obtained (for participants aged 7 to 9 years), and informed consent form was signed and dated by the parent(s) or another legally acceptable representative and by an independent witness, if required by local regulations
Participant and parent/legally acceptable representative were able to attend all scheduled visits and to comply with all study procedures

Toddlers

Aged 12 to 23 months on the day of inclusion
Informed consent form has been signed and dated by the parent(s) or other legally acceptable representative and by an independent witness if required by local regulations
Participant and parent/legally acceptable representative are able to attend all scheduled visits and to comply with all study procedures

Exclusion Criteria

Participants were excluded from the study if any of the following criteria apply:

Adults (aged 18 years and above), Adolescents (aged 10 to 17 years), Children (aged 2 to 9 years) and Toddlers (aged 12 to 23 months)

Participation at the time of study enrollment (or in the 4 weeks preceding the trial vaccination) or planned participation during the present trial period in another clinical study investigating a vaccine, drug, medical device, or medical procedure
Receipt of any vaccine in the 4 weeks preceding the study intervention administration or planned receipt of any vaccine in the 4 weeks following study intervention administration except for influenza vaccination, which may be received at least 2 weeks before or after study vaccine. This exception includes monovalent pandemic influenza

View full record on ClinicalTrials.gov →

Data sourced from ClinicalTrials.gov (NCT06228586). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication. Informational only — not medical advice.