Meningococcal quadrivalent ACYW-TT conjugated vaccine at 6-23 months: phase III study (US/Puerto Rico)

Cheryl Duffy; Olga Lyabis; Mandeep Singh Dhingra; Betzana Zambrano; Julie Chaix; Olga Syrkina; Siham B'Chir; Sandeep Gupta; Christine Rehm

doi:10.1038/s41390-026-04833-8

Meningococcal quadrivalent ACYW-TT conjugated vaccine at 6-23 months: phase III study (US/Puerto Rico)

Pediatr Res. 2026 Mar 6. doi: 10.1038/s41390-026-04833-8. Online ahead of print.

Authors

Cheryl Duffy^{1

2}, Olga Lyabis³, Mandeep Singh Dhingra⁴, Betzana Zambrano⁵, Julie Chaix⁶, Olga Syrkina⁷, Siham B'Chir⁸, Sandeep Gupta⁴, Christine Rehm⁹

Affiliations

¹ Children's Community Pediatrics-Kids Way, Hermitage, PA, USA.
² The University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
³ Global Clinical Development Strategy, Sanofi, Marcy L'Étoile, France.
⁴ Global Clinical Development Strategy, Sanofi, Swiftwater, PA, USA.
⁵ Global Clinical Development Strategy, Sanofi, Montevideo, Uruguay.
⁶ Global Immunology, Sanofi, Marcy L'Étoile, France.
⁷ Patient Safety and Pharmacovigilance, Sanofi R&D, Cambridge, MA, USA.
⁸ Global Clinical Development Biostatistical Sciences, Sanofi, Marcy L'Étoile, France.
⁹ Global Clinical Development Strategy, Sanofi, Swiftwater, PA, USA. Christine.rehm@sanofi.com.

PMID: 41792337
DOI: 10.1038/s41390-026-04833-8

Abstract

Background: A quadrivalent meningococcal tetanus toxoid-conjugate vaccine, MenACYW-TT, was developed to provide broad protection against invasive meningococcal disease across all age groups. We evaluated the immunogenicity and safety of MenACYW-TT as a two-dose series (1 + 1 schedule) co-administered with routine pediatric vaccines to infants from 6 months of age.

Methods: This phase III modified double-blind, randomized study (NCT03691610) enrolled healthy infants (n = 750) and toddlers (n = 200). Infants were randomized 1:1 to receive MenACYW-TT (Group 1) or another quadrivalent conjugate vaccine, MenACWY-CRM (Group 2) at ages 6-7 and 12-13 months, co-administered with routine vaccines. Toddlers were randomized 1:1 to receive MenACYW-TT (Group 3) or another quadrivalent conjugate vaccine, MenACWY-DT (Group 4) at ages 17-19 and 20-23 months. Functional antibodies against the four meningococcal serogroups were assessed by serum bactericidal antibody assay using human complement (hSBA). Safety was assessed up to 6 months post-vaccination.

Results: Seroresponse to MenACYW-TT was non-inferior to that with MenACWY-CRM against all four serogroups (seroresponse rates 30 days post-dose 2 were 89.4-99.3% and 82.9-97.7%, respectively). All vaccines were well tolerated.

Conclusions: These findings support MenACYW-TT administration as a two-dose series in children from 6 months of age.

Study registration: Clinicaltrials.gov: NCT03691610.

Impact: When administered as a two-dose series (1 + 1 schedule), MenACYW-TT demonstrated comparable/higher immunogenicity to MenACWY-CRM (ages 6-7 and 12-13 months) and the safety profiles of these quadrivalent meningococcal vaccines were similar. MenACYW-TT was non-inferior to MenACWY-CRM in terms of seroresponse rates and proportion of participants with antibody titer ≥1:8 after a second dose at age 12-13 months. This phase III study is the first to confirm the safety and immunogenicity of MenACYW-TT in infants and supports its use as a two-dose series from 6 months of age.

Associated data

ClinicalTrials.gov/NCT03691610