Different Long-Term Duration of Seroprotection against Neisseria meningitidis in Adolescents and Middle-Aged Adults after a Single Meningococcal ACWY Conjugate Vaccination in The Netherlands.

Milou Ohm,Mariëtte B. van Ravenhorst,Debbie M. van Rooijen,Elisabeth A.M. Sanders,Guy A.M. Berbers,Axel A. Bonačić Marinović,Anne-Marie Buisman,Marieke van der Heiden

doi:10.3390/vaccines8040624

Abstract

Neisseria meningitidis is often asymptomatically carried in the nasopharynx but may cause invasive meningococcal disease, leading to morbidity and mortality. Meningococcal conjugate vaccinations induce functional protective antibodies against capsular antigens, but seroprotection wanes over time. We measured functional antibody titers five years after administration of a single dose of the meningococcal ACWY-polysaccharide-specific tetanus toxoid-conjugated (MenACWY-TT) vaccine in adolescents and middle-aged adults in the Netherlands, using the serum bactericidal antibody with baby rabbit complement (rSBA) assay. Protection was defined as rSBA titer ≥8. The meningococcal ACWY-specific serum IgG concentrations were measured with a multiplex immunoassay. Duration of protection was estimated by a bi-exponential decay model. Sufficient protection for MenC, MenW, and MenY was achieved in 94–96% of the adolescents five years postvaccination, but, in middle-aged adults, only in 32% for MenC, 65% for MenW and 71% for MenY. Median duration of protection for MenCWY was 4, 14, and 21 years, respectively, in middle-aged adults, while, in adolescents, it was 32, 98, and 33 years. Our findings suggest that adolescents, primed in early childhood with MenC conjugate vaccination, remain sufficiently protected after a single dose of MenACWY-TT vaccine. Middle-aged adults without priming vaccination show fast waning of antibodies, particularly MenC, for which protection is lost after four years.

Highlights

As a commensal bacterium, Neisseria meningitidis resides in the nasopharynx in humans mostly without clinical symptoms
A primary MenACWY-TT vaccination was administered to 225 healthy adolescents who were all once primed with a meningococcal C (MenC)-TT vaccine (NeisVac-C) at an age between 14 months and 3 years, and to 204 healthy middle-aged adults who were naïve to meningococcal vaccination
Seroprotection for MenCWY is maintained in adolescents five years after a MenACWY-TT vaccination and estimated duration of protection is more than 30 years for MenC and

Summary

Introduction

Neisseria meningitidis resides in the nasopharynx in humans mostly without clinical symptoms. Sometimes encapsulated serogroups may invade the bloodstream of the human host, and cause invasive meningococcal disease (IMD) [1,2]. IMD has both severe acute and life-long consequences and is a major cause of mortality [3]. Vaccination with meningococcal conjugate vaccines induces the production of protective antibodies against the polysaccharide capsule of the meningococcal bacterium [4]. A vaccine induces a cellular memory response, the response might be too slow to provide protection against Neisseria meningitidis. A memory response can take up to five days, while an invasive disease can manifest itself within hours after encountering the pathogen [5,6]

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