title: Age-specific differences in duration of clinical protection after vaccination with meningococcal polysaccharide A vaccine.
abstract: Sequential case-control studies were used to monitor changes in the clinical protection induced by group A meningococcal polysaccharide vaccine over a 3-year period. Overall, vaccine efficacy declined from 87% 1 year after vaccination to 70% and 54% at 2 and 3 years, respectively. When stratified by age at time of vaccination the data showed that, although vaccine efficacy remained high in children greater than or equal to 4 years of age (vaccine efficacy 85%, 74%, and 67% at 1, 2, and 3 years after vaccination, respectively), it declined dramatically in those less than 4 years of age at time of vaccination (vaccine efficacy 100%, 52%, and 8%, respectively, at 1, 2, and 3 years after vaccination). Thus, a single dose of group A meningococcal vaccine does not yield lasting clinical protection in children less than 4 years of age.
authors.forename: A L
authors.initials: AL
authors.lastname: Reingold
authors.forename: C V
authors.initials: CV
authors.lastname: Broome
authors.forename: A W
authors.initials: AW
authors.lastname: Hightower
authors.forename: G W
authors.initials: GW
authors.lastname: Ajello
authors.forename: G A
authors.initials: GA
authors.lastname: Bolan
authors.forename: C
authors.initials: C
authors.lastname: Adamsbaum
authors.forename: E E
authors.initials: EE
authors.lastname: Jones
authors.forename: C
authors.initials: C
authors.lastname: Phillips
authors.forename: H
authors.initials: H
authors.lastname: Tiendrebeogo
authors.forename: A
authors.initials: A
authors.lastname: Yada
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001428:Bacterial Vaccines; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008585:Meningitis, Meningococcal / Q000453:epidemiology / Q000517:prevention & control*; D022401:Meningococcal Vaccines; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D014611:Vaccination
chemical_list: D001428:Bacterial Vaccines; D022401:Meningococcal Vaccines; D011135:Polysaccharides, Bacterial; C043226:meningococcal group A polysaccharide