Antibody persistence and immune memory 15 months after priming with an investigational tetravalent meningococcal tetanus toxoid conjugate vaccine (MenACWY-TT) in toddlers and young children

Abstract

The present extension study, conducted in children originally vaccinated at 12–14 mo or 3–5 y of age, assessed antibody persistence and immune memory induced by an investigational tetravalent meningococcal serogroups A, C, W-135 and Y tetanus toxoid conjugate vaccine (MenACWY-TT). In the original study, participants were randomized to receive one dose of MenACWY-TT or licensed age-appropriate meningococcal control vaccines. Fifteen months post-vaccination, all participants underwent serum sampling to evaluate antibody persistence and participants previously vaccinated as toddlers received a polysaccharide challenge to assess immune memory development.

 

Exploratory comparisons showed that (1) All children and ≥ 92.3% of the toddlers maintained serum bactericidal (rSBA) titers ≥ 1:8 at 15 mo post MenACWY-TT vaccination; statistically significantly higher rSBA geometric mean titers (GMTs) were observed compared with control vaccines. (2) At one month after polysaccharide challenge, all toddlers primed with MenACWY-TT or with the monovalent serogroup C conjugate vaccine had rSBA titers ≥ 1:8 and ≥ 1:128 for serogroup C and similar rSBA-GMTs; rSBA-GMTs for serogroups A, W-135 and Y were statistically significantly higher in toddlers primed with MenACWY-TT compared with the control vaccine. Thus, a single dose of MenACWY-TT induced persisting antibodies in toddlers and children and immune memory in toddlers.

This study has been registered at www.clinicaltrials.gov NCT00126984.

Keywords: :

• children
• immune memory
• meningococcal vaccine
• persistence
• tetanus toxoid
• toddlers

Disclosure of Potential Conflicts of Interest

MK received honoraria or consulting fees as well as support for meetings, travel or accommodation expenses from GSK in the past 3 y. YB, VB, DB and JM are employees of GSK Biologicals. YB, DB and JM declare stock ownership in GSK. DB is also inventor of certain GSK Biologicals patents.

Funding

GSK Biologicals was the funding source and was involved in all stages of the study conduct and analysis. GSK Biologicals also took responsibility for all costs associated with the development and publishing of the present manuscript.

Acknowledgments

The authors are indebted to the study participants and their parents, clinicians, nurses, and laboratory technicians at the study site as well as to the sponsor’s project staff and to the study managers for their support and contributions throughout the study. We are grateful to Doctors Angermayr, Busse, Doering, Grunert, Hoernlein, Kieninger-Baum, Kimmig, Knecht, Maurer, Taube, Van Stiphout, Wagner, Wittermann and all teams for their contribution to this study, as well as Werner Kroeniger, Margit Spacek and Sophie Ledant (GSK Biologicals) for their supports. The authors would also like to thank Koen Maleux and Pascal Lestrate, who coordinated the laboratory testing for this study, Laurence Fissette (GSK Biologicals) for performing the statistical analysis and Emmanuel Aris (GSK Biologicals) for statistical advice. Finally we thank Claire Verbelen (XPE Pharma and Science) who provided medical writing services and Stephanie Harbers (GSK Biologicals), Virginie Durbecq and Juliette Gray (XPE Pharma and Science) for editorial assistance and manuscript coordination.

Supplementary Material

Supplementary materials can be found at: www.landesbioscience.com/journals/vaccines/article/20229