Immunogenicity and safety of a quadrivalent meningococcal tetanus toxoid-conjugate vaccine (MenACYW-TT) administered concomitantly with hexavalent acellular pertussis combined vaccine in healthy toddlers in Mexico: a phase III randomized study

Abstract

Background: Children are at increased risk of developing invasive meningococcal disease (IMD). Vaccination is an effective prevention tool, and its use with other pediatric vaccines offers programmatic benefits. Methods: A phase III study, open, randomized, descriptive, in toddlers 12-23 months of age evaluated the immunogenicity and safety of MenACYW-TT tetanus toxoid conjugate vaccine against serogroups A, C, W, and Y,  co-administered with pediatric vaccines (measles, mumps, rubella [MMR] varicella [V] in South Korea and Thailand, acellular hexavalent combined vaccine against, diphtheria, tetanus, pertusis, polio, hepatitis B and Haemophilus influenzae b [DTaP-IPV-HepB-Hib] in Mexico, and pneumococcal conjugate vaccine [PCV13] in Russia); that study was previously published. We only present the part of the study conducted in 400 participants in Mexico which includes additional unpublished immunogenicity and safety results, not included in the publication of the global study. Immunogenicity of each serogroup was assessed using the serum bactericidal antibody assay using human complement (hSBA) and for a subset of subjects, baby rabbit complement (rSBA). The safety of the vaccine was described 30 days after vaccination. Results: The proportion of participants with seroprotection (hSBA ≥1:8) for all serogroups on Day 30 of vaccination was comparable for MenACYW-TT alone (≥89,9%) and MenACYW-TT+DTaP-IPV-HepB-Hib (≥90,3%). The safety profiles of MenACYW-TT alone and DTaP-IPV-HepB-Hib, administered with or without MenACYW-TT were comparable. Conclusions: Coadministration of MenACYW-TT+DTaP-IPV-HepB-Hib in toddlers had no clinically relevant effect on the immunogenicity and safety of these vaccines. Both vaccines can be co-administered at 12-23 months of age. While some of these results in this manuscript have already been published, expanded information on Mexico’s results, with additional unpublished immunogenicity and safety data provide relevant information for Latinamerican healthcare professionals who may require concomitant administration of MenACYW-TT vaccine with hexavalent vaccine, or for health authority decision-making of a concomitant indication of these two vaccines in national immunization schedules, in order to diminish the possibility of missed vaccination opportunities.