Kirsten P Perrett1, Peter C Richmond, Ray Borrow, Terry Nolan, Jodie McVernon. 1. From the *Vaccine and Immunisation Research Group (VIRGo), Murdoch Childrens Research Institute and Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia, †School of Paediatrics and Child Health, University of Western Australia, Telethon Institute for Child Health Research, Princess Margaret Hospital for Children, Perth, Western Australia, Australia; and ‡Vaccine Evaluation Unit, Public Health England, Manchester Royal Infirmary, Manchester, Greater Manchester, United Kingdom.
Abstract
BACKGROUND: In Australia, following the introduction of serogroup C meningococcal (MenC) conjugate vaccine for toddlers and catch-up immunization through adolescence, MenC disease incidence plummeted and remains low. However, individual protection following MenC conjugate vaccination, particularly in young children, may be short-lived. We investigated the persistence of MenC serum bactericidal antibody (SBA) titers in adolescents, more than 7 years after a single "catch-up" dose of MenC conjugate vaccine. We also investigated their exposure and susceptibility to meningococcal serogroups A, W and Y. METHODS: MenC SBA titers and Men A, C, W and Y IgG geometric mean concentration were measured in 240 healthy 11- to 16-year-old adolescents. The correlate of protection was an rSBA titer of ≥8. RESULTS: An rSBA≥8 was observed in 105 [44% (95% confidence interval {CI}, 37-50%)] of 240 adolescents (mean age, 13.2 years, mean interval since MenC immunization, 8.2 years). The proportion with an rSBA≥8, geometric mean rSBA titer and geometric mean IgG concentration increased with age, from 22% to 75%, 3.7 to 33.4 and 0.13 to 0.52 μg/mL, in participants who received MenC vaccine at mean age 2.8 to 7.5 years, respectively. Natural acquired antibody to Men A, W and Y was low with IgG geometric mean concentrations of 1.26, 0.38 and 0.47 μg/mL, respectively. CONCLUSIONS: More than half of Australian adolescents have inadequate serological protection against MenC disease and low natural immunity to MenA, W and Y.
BACKGROUND: In Australia, following the introduction of serogroup C meningococcal (MenC) conjugate vaccine for toddlers and catch-up immunization through adolescence, MenC disease incidence plummeted and remains low. However, individual protection following MenC conjugate vaccination, particularly in young children, may be short-lived. We investigated the persistence of MenC serum bactericidal antibody (SBA) titers in adolescents, more than 7 years after a single "catch-up" dose of MenC conjugate vaccine. We also investigated their exposure and susceptibility to meningococcal serogroups A, W and Y. METHODS: MenC SBA titers and Men A, C, W and Y IgG geometric mean concentration were measured in 240 healthy 11- to 16-year-old adolescents. The correlate of protection was an rSBA titer of ≥8. RESULTS: An rSBA≥8 was observed in 105 [44% (95% confidence interval {CI}, 37-50%)] of 240 adolescents (mean age, 13.2 years, mean interval since MenC immunization, 8.2 years). The proportion with an rSBA≥8, geometric mean rSBA titer and geometric mean IgG concentration increased with age, from 22% to 75%, 3.7 to 33.4 and 0.13 to 0.52 μg/mL, in participants who received MenC vaccine at mean age 2.8 to 7.5 years, respectively. Natural acquired antibody to Men A, W and Y was low with IgG geometric mean concentrations of 1.26, 0.38 and 0.47 μg/mL, respectively. CONCLUSIONS: More than half of Australian adolescents have inadequate serological protection against MenC disease and low natural immunity to MenA, W and Y.
Authors: Joan L Robinson; Sergio Fanella; Alison Lopez; Craig Frankel; Jane McDonald; Mohammad Alghounaim; Robert Slinger; Jennifer Bowes; Sarah Khan; Jeannette L Comeau; Kirk Leifso; John Gunawan; Michelle Barton Journal: Can Commun Dis Rep Date: 2020-10-01