Poster Presentation 25th International Pathogenic Neisseria Conference 2026

Safety, tolerability, and immunogenicity of meningococcal combined MenACWY-7B vaccine in healthy infants: a randomized, partially blinded phase 2 study (#047)

Federico Martinon-Torres 1 , Sara Manzella 2 , Vikramjit Singh 2 , Vincent Weynants 3 , Manuel Baca 4 , Shaun Barnabas 5 , Luis Cousin 6 , Dominic Kelly 7 8 , Michael Horn 9 , Terisha Naidoo 10 , Luis Martinez 11 , Ignacio Salamanca de la Cueva 12 , Leszek Szenborn 13 , Izabela Tarczon 14 , Marco Costantini 2 , Maria Lattanzi 2 , Pavitra Keshavan 2 , Ugo D’Oro 2
  1. Hospital Clínico Universitario de Santiago, Santiago De Compostela, Spain
  2. GSK, Sienna, Italy
  3. GSK, Rixensart, Belgium
  4. Hospital Quirónsalud Málaga, Malaga, Spain
  5. Stellenbosch University, Cape Town, South Africa
  6. Demedica S. de R. L. de C.V., San Pedro Sula, Honduras
  7. Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, United Kingdom
  8. NIHR Oxford Biomedical Research Centre, Oxford University Hospitals, NHS Foundation Trust, Oxford, United Kingdom
  9. Pediatric Office Dr. Horn, Schoenau, Germany
  10. Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa
  11. Hospital Materno Infantil San Lorenzo de Los Mina, Santo Domingo Este, Dominican Republic
  12. Unidad de Investigación, Grupo IHP, Universidad de Málaga, Málaga, Spain
  13. Uniwersytecki Szpital Kliniczny im., Wroclaw, Poland
  14. Przyladek Zdrowia Poradnie Medyczne, Krakow, Poland

Background: MenACWY-7B is a pentavalent meningococcal vaccine comprising antigenic components from established vaccines MenACWY-CRM and 4-component MenB (4CMenB), and 3 additional MenB antigen components.

 

Aim/Methods: This completed phase 2 study (NCT05082285) was designed to assess the safety and immunogenicity of 2 formulations of MenACWY-7B and MenABCWY in healthy infants 55–89 days of age at first vaccination. Infants were randomized 1:1:1:1 to receive a formulation containing either a low (MenACWY-7B-low) or high dose (MenACWY-7B-high) of the novel antigen components, MenABCWY, or a combination of two control vaccines MenACWY-TT + 4CMenB. Vaccines were given at three timepoints: 2, 4, and 12 months of age. Immunogenicity was measured by human serum bactericidal assay (hSBA) 30 days after the second and third dose.

 

Results: A total of 724 infants received study vaccines (MenACWY-7B-low, n=188; MenACWY-7B-high, n=179; MenABCWY, n=175; MenACWY-TT + 4CMenB, n=182). Both formulations of MenACWY-7B and MenABCWY were well tolerated. Reactogenicity and safety profiles were similar to the control vaccines and no safety issues were identified. After all vaccinations, the immune response against ACWY serogroups was comparable between MenACWY-7B formulations. For both formulations, the percentages of participants with hSBA titers above the lower limit of quantification (≥LLOQ) were comparable to the control (MenACWY-TT) for ACWY serogroups, while geometric mean titers (GMTs) were lower than the control. Immune response against MenB antigens was also comparable between MenACWY-7B formulations. For MenB antigens common to MenACWY-7B and 4CMenB, the percentages of participants with hSBA titers ≥LLOQ and GMTs for both MenACWY-7B formulations were higher than 4CMenB for fHbp, NHBA, and PorA, while responses were lower than 4CMenB for NadA. The immune response elicited by both MenACWY-7B formulations was higher than 4CMenB for the novel MenB antigens. Across all MenB antigens, MenABCWY elicited lower or comparable responses with respect to MenACWY-7B and control.

 

Conclusions: These results demonstrate the added value of the novel antigen components in MenACWY-7B. There are no meaningful differences in immunogenicity or safety profiles between the two MenACWY-7B formulations tested. 

Funding: GSK.