Influence of prior meningococcal C polysaccharide vaccination on the response and generation of memory after meningococcal C conjugate vaccination in young children.
To determine whether the immunological hyporesponsiveness induced by meningococcal AC polysaccharide (MACP) vaccines can be overcome by meningococcal C conjugate (MCC) vaccine in young children, serum bactericidal antibody (SBA) serogroup C-specific IgG and IgG avidity indices were measured in young children who received MACP vaccine, followed 7 months later by MCC vaccine, and their responses were compared with those in age-matched MACP-naive control children, who received a single dose of MCC vaccine. For children <1 year of age at MACP vaccination, the SBA geometric mean titer (GMT) after MCC vaccination was lower (P=.022) and proportions with SBA titers <8 (P=.0083) or <128 (P=.0091) were higher than those in the control children. For older children, there was no difference in the SBA GMTs between the study and control groups (P>.5) or in the proportion with SBA titers <8 (P=1.00) or <128 (P=.98). No increase in avidity occurred after MACP vaccination, whereas avidity increased significantly 1 month after MCC vaccination, with a further increase at 6 months, which indicates that the induction of immunological memory was not impaired.
Borrow
R
R
Public Health Laboratory Service Meningococcal Reference Unit, Withington Hospital, Manchester, United Kingdom.
Goldblatt
D
D
Andrews
N
N
Richmond
P
P
Southern
J
J
Miller
E
E
D000367:Age Factors; D000907:Antibodies, Bacterial / Q000097:blood*; D000915:Antibody Affinity; D000917:Antibody Formation; D001770:Blood Bactericidal Activity; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007117:Immunization, Secondary; D007074:Immunoglobulin G / Q000097:blood*; D007156:Immunologic Memory; D007223:Infant; D022401:Meningococcal Vaccines / Q000627:therapeutic use*; D009345:Neisseria meningitidis / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000627:therapeutic use*
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D022401:Meningococcal Vaccines; D018074:Vaccines, Conjugate; C410218:serogroup C meningococcal conjugate vaccine