Decline in meningococcal antibody levels in African children 5 years after vaccination and the lack of an effect of booster immunization.
Antibodies to group A meningococcal polysaccharide were measured by hemagglutination (HA) and by ELISA in sera obtained from Gambian children before vaccination and 3 weeks, 2 years, and 5 years after vaccination with a group A + group C meningococcal capsular polysaccharide vaccine. Children were 1-4 years old at the time of vaccination. Most showed a good initial response to vaccination, including those aged 1-2 years. However, antibody titers declined progressively during follow-up, and 5 years after vaccination, antibody titers measured by both HA and ELISA had returned to prevaccination levels. This decline was not influenced significantly by a booster dose of vaccine given 2 years after initial immunization. Administration of malaria chemoprophylaxis reduced the rate at which antibody levels fell after initial immunization. Sustained protection of children against group A meningococcal disease will require the development of vaccines that are immunogenic in infants and that can induce T cell memory.
Ceesay
S J
SJ
Medical Research Council Laboratories, Fajara, Banjul, The Gambia.
Allen
S J
SJ
Menon
A
A
Todd
J E
JE
Cham
K
K
Carlone
G M
GM
Turner
S H
SH
Gheesling
L L
LL
DeWitt
W
W
Plikaytis
B D
BD
D000907:Antibodies, Bacterial / Q000097:blood*; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005714:Gambia / Q000453:epidemiology; D006384:Hemagglutination; D006801:Humans; D007117:Immunization, Secondary; D007223:Infant; D008288:Malaria / Q000517:prevention & control; D008297:Male; D008585:Meningitis, Meningococcal / Q000453:epidemiology / Q000276:immunology*; D022401:Meningococcal Vaccines; D009345:Neisseria meningitidis / Q000276:immunology*; D014611:Vaccination
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D022401:Meningococcal Vaccines