Serologic responses to ACYW135 polysaccharide meningococcal vaccine in Saudi children under 5 years of age.
Infect Immun
; 73(5): 2932-9, 2005 May.
Article
in En
| MEDLINE
| ID: mdl-15845499
ABSTRACT
An immunization campaign with meningococcal ACYW135 polysaccharide vaccine was conducted in 2003 by the Saudi Arabian Ministry of Health and included a study to evaluate the immune responses in children under 5 years of age in the Al Qassim region of Saudi Arabia. Children who were >/=24 months old were given one dose of tetravalent polysaccharide vaccine, while younger children were given two doses with an interval of 2 to 3 months. Blood samples were collected prevaccination and 1 month after the second dose for children younger than 24 months old and 1 month after the single dose for older children. Serogroup-specific antibody responses were determined by serum bactericidal antibody (SBA) assays and a tetraplex immunoglobulin G (IgG) bead assay. Significant increases in the proportions of individuals who were >/=24 months old with SBA titers of >/=8 were observed pre- to postvaccination for all serogroups. Age-dependent increases in the percentage of individuals with SBA titers of >/=8 1 month postvaccination were observed for each serogroup. Age-dependent increases in postvaccination IgG levels were observed for serogroup A (menA), serogroup W135 (menW), and serogroup Y (menY) but not for serogroup C (menC). Two doses of tetravalent polysaccharide vaccine in individuals who were =18 months old were poorly immunogenic for menC, menW, and menY. However, for menA, 42% of the children who were 18 months old were putatively protected with SBA titers of >/=8. A high percentage of subjects who were >/=2 years of age were putatively protected for menA; a similar level was observed for menY for children who were 4 years of age but not for younger children. However, for menC and menW poor levels of putative protection were still evident at 4 years of age.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Polysaccharides, Bacterial
/
Meningococcal Vaccines
/
Antibodies, Bacterial
/
Neisseria meningitidis
Type of study:
Clinical_trials
Limits:
Child, preschool
/
Humans
/
Infant
Country/Region as subject:
Asia
Language:
En
Journal:
Infect Immun
Year:
2005
Document type:
Article
Affiliation country:
United kingdom