Ability of 3 different meningococcal C conjugate vaccines to induce immunologic memory after a single dose in UK toddlers.
To test for immunologic memory after a single dose of meningococcal C conjugate (MCC) vaccine in toddlers, 226 children 12-18 months old were randomized to receive 1 of 3 MCC vaccines, with a C polysaccharide booster 6 months later. The protein conjugate was diphtheria mutant toxoid in 2 vaccines (MCC-CRM(197)) and was tetanus toxoid in the third (MCC-TT). One month after the MCC vaccines, 91%-100% of children had serum bactericidal antibody (SBA) titers > or =8, and 89%-100% had a > or =4-fold increase. Geometric mean titer (GMT) increased from <4 to 215 (95% confidence interval [CI], 166-279). MCC-TT induced higher SBA GMTs (P<.001) and higher proportions with SBA > or =8 (P=.02) than did the MCC-CRM(197) vaccines. By 6 months, GMTs had decreased to 55.1 (95% CI, 40-76), but IgG antibody avidity increased (P<.001). Induction of immunologic memory was confirmed by a GMT of 1977 (range, 1535-2547) after the polysaccharide booster and a further increase in avidity. This evidence justified the use of a single dose in a catch-up immunization program for children 1-18 years old.
Richmond
P
P
Immunisation Division, Communicable Disease Surveillance Centre, Public Health Laboratory Service, London, United Kingdom.
Borrow
R
R
Goldblatt
D
D
Findlow
J
J
Martin
S
S
Morris
R
R
Cartwright
K
K
Miller
E
E
D000907:Antibodies, Bacterial / Q000097:blood*; D000915:Antibody Affinity; D004168:Diphtheria Toxoid / Q000276:immunology; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007156:Immunologic Memory; D007223:Infant; D008297:Male; D016920:Meningitis, Bacterial / Q000097:blood / Q000517:prevention & control*; D022401:Meningococcal Vaccines / Q000008:administration & dosage / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000276:immunology; D013745:Tetanus Toxoid / Q000276:immunology; D006113:United Kingdom; D014611:Vaccination; D017778:Vaccines, Combined / Q000008:administration & dosage / Q000276:immunology; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000276:immunology*
D000907:Antibodies, Bacterial; D004168:Diphtheria Toxoid; D007074:Immunoglobulin G; D022401:Meningococcal Vaccines; D011135:Polysaccharides, Bacterial; D013745:Tetanus Toxoid; D017778:Vaccines, Combined; D018074:Vaccines, Conjugate