Immunogenicity and safety of a booster dose of the 10-valent pneumococcal haemophilus influenzae protein D conjugate vaccine coadministered with the tetravalent meningococcal serogroups A, C, W-135 and y tetanus toxoid conjugate vaccine in toddlers: A randomized trial

Background: This open, randomized clinical trial (NCT00758264) evaluated the coadministration of a booster dose of the 10-valent pneumococcal conjugate vaccine (PHiD-CV) and a single dose of the tetravalent meningococcal conjugate vaccine (MenACWY-TT) in Taiwanese and Mexican toddlers. Methods: Healthy toddlers aged 12-23 months (N = 363) were randomized (2:1:1) to receive either both vaccines at first visit, MenACWY-TT at first visit and 1 month later PHiD-CV, or PHiD-CV at first visit and 1 month later MenACWY-TT. Immune responses were measured 1 month after MenACWY-TT vaccination by meningococcal serum bactericidal activity (rSBA) assay and 1 month after PHiD-CV vaccination by pneumococcal 22F-inhibition enzyme-linked immunosorbent assay and functional opsonophagocytic activity assay. Solicited and unsolicited symptoms were recorded for days 4 and 31 postvaccination, respectively. Serious adverse events were recorded throughout the study. Results: The prespecified criteria for noninferiority of coadministration versus individual administrations were met for all meningococcal serogroups (in terms of percentages of toddlers with rSBA titer 8) and all vaccine pneumococcal serotypes (in terms of antibody geometric mean concentration ratios), except pneumococcal serotype 18C. For each meningococcal serogroup, 97.5% of toddlers across the 3 groups had rSBA titers 128 at 1 month after MenACWY-TT vaccination. For each pneumococcal serotype, at 1 month after PHiD-CV vaccination, 96.0% and 92.9% of toddlers across the 3 groups had antibody concentrations 0.2 μg/mL and opsonophagocytic activity titers 8, respectively. The safety profiles of both vaccines when coadministered were clinically acceptable. Conclusions: This study supports the coadministration of PHiD-CV and MenACWY-TT in toddlers.