title: Effects of prior polysaccharide vaccination on magnitude, duration, and quality of immune responses to and safety profile of a meningococcal serogroup C tetanus toxoid conjugate vaccination in adults.
abstract: Extensive use of meningococcal AC polysaccharide (MACP) vaccines has raised concerns about induction of immunologic hyporesponsiveness to C polysaccharide. We investigated the immunogenicity and safety of a meningococcal C-tetanus conjugate (MCC-TT) vaccine in naive adults and prior MACP vaccinees. Laboratory staff (n = 113) were recruited; 73 were naive to meningococcal vaccination, and 40 had previously received > or =1 dose of MACP vaccine. Blood was taken prior to MCC-TT vaccination and 1 week, 1 month, and 6 months later. At each time point, proportions of subjects with serum bactericidal antibody (SBA) titers of > or =8 or > or =128 were similar (P > 0.46); >94% of subjects achieved titers of > or =128 at 1 month. However, the geometric mean titer (GMT) of SBA at 1 month was higher in the naive (1,757; 95% confidence interval [95% CI], 1,102 to 2,803) than in the previously vaccinated (662; 95% CI, 363 to 1,207) group (P = 0.02), and similarly at 6 months (P < 0.001). Conversely, geometric mean concentrations (GMCs) of serogroup C-specific immunoglobulin G (IgG) were significantly higher in the previously vaccinated group pre-MCC-TT and at 1 week; the groups were similar at 1 month, and there was some evidence that the GMC for the previously vaccinated group was higher at 6 months. Qualitative differences in antibodies between groups were demonstrated by using the SBA/IgG ratio, though avidity measures were similar for the two groups throughout the study. MCC-TT was well tolerated, with similar safety profiles in the two groups. Pain in the arm and headache were the most frequently reported events following vaccination. The study shows that MCC-TT is safe and immunogenic in naive and previously MACP-vaccinated adults, though the magnitude and persistence of postvaccination SBA responses in the latter group were lower.
authors.affiliation: Immunisation Department, Communicable Disease Surveillance Centre, Health Protection Agency, 61 Colindale Ave., Colindale, London, United Kingdom. jo.southern@hpa.org.uk
authors.forename: Jo
authors.initials: J
authors.lastname: Southern
authors.forename: Sarah
authors.initials: S
authors.lastname: Deane
authors.forename: Lindsey
authors.initials: L
authors.lastname: Ashton
authors.forename: Ray
authors.initials: R
authors.lastname: Borrow
authors.forename: David
authors.initials: D
authors.lastname: Goldblatt
authors.forename: Nick
authors.initials: N
authors.lastname: Andrews
authors.forename: Paul
authors.initials: P
authors.lastname: Balmer
authors.forename: Rhonwen
authors.initials: R
authors.lastname: Morris
authors.forename: J Simon
authors.initials: JS
authors.lastname: Kroll
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Miller
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000032:analysis*; D003257:Consumer Product Safety; D005260:Female; D006801:Humans; D007156:Immunologic Memory; D008297:Male; D008589:Meningococcal Infections / Q000276:immunology / Q000517:prevention & control; D022401:Meningococcal Vaccines / Q000276:immunology*; D038542:Neisseria meningitidis, Serogroup C / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D015610:Serum Bactericidal Test; D013745:Tetanus Toxoid / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D022401:Meningococcal Vaccines; D011135:Polysaccharides, Bacterial; D013745:Tetanus Toxoid; D018074:Vaccines, Conjugate