ABSTRACT
Meningococcal group C polysaccharide-protein conjugate vaccines (MCV) prime infants and children for memory anticapsular responses upon subsequent exposure to unconjugated polysaccharide. The objective of this study was to determine whether MCV primes vaccine-naïve adults and adults previously vaccinated with meningococcal polysaccharide vaccine (MPSV) for memory antibody responses. Meningococcal vaccine-naïve adults were randomized to receive either MCV (MCV/naïve group) (n = 35) or pneumococcal conjugate vaccine (PCV) (PCV/naïve group) (n = 34). Participants with a history of receiving MPSV were given MCV (MCV/MPSV group) (n = 26). All subjects were challenged 10 months later with one-fifth of the usual dose of MPSV (10 mug of each polysaccharide). Sera were obtained before the conjugate vaccination and before and 7 days after the MPSV challenge and assayed for immunoglobulin G (IgG) anticapsular antibody concentrations and bactericidal titers. The MCV/naïve group had 7- to 10-fold-higher serum IgG and bactericidal responses after the MPSV challenge than the PCV/naïve group (P < 0.001). The increases (n-fold) in anticapsular antibody concentrations in the MCV/naïve group were greatest in subjects with antibody concentrations of Subject(s)
Antibodies, Bacterial/immunology
, Immunologic Memory/immunology
, Polysaccharides, Bacterial/immunology
, Vaccines, Conjugate/immunology
, Adolescent
, Adult
, Antibodies, Bacterial/biosynthesis
, Dose-Response Relationship, Immunologic
, Enzyme-Linked Immunosorbent Assay/methods
, Evaluation Studies as Topic
, Female
, Humans
, Immunization Schedule
, Immunization, Secondary
, Immunoglobulin G/blood
, Male
, Middle Aged
, Polysaccharides, Bacterial/administration & dosage
, Vaccination
, Vaccines, Conjugate/administration & dosage