[Levels of bactericidal antibodies against meningococcus C after vaccination in 2- to 6-year-old children in Andalusia].
BACKGROUND
In 1997, 18.5% of the cases of Meningococcal Disease caused b serogroup C in Andalusia were children between 2 and 4 years of age; ages where the initial immune response and the duration of the capsular A + C meningococcal polysaccharide vaccine is less than in older age groups. Research was designed in order to measure the immune response produced by this vaccine in children from 2 to 6 years of age and to compare it with the natural immunity present in unvaccinated children.


METHODS
I. Dual monitoring study: a) groups of children vaccinated previously and control groups, b) groups of children who were going to be vaccinated, for pre and post-vaccination (1, 6 and 12 months) analysis and a control group. II. The bactericidal activity was measured according to the standardised protocol of the CDC with regard to the strain of N. meningitidis C-11. The sera with bactericidal activity (TAB) > 1:8 were considered to be protective.


RESULTS
1 and 2 months following vaccination, the proportion of TAB > 1:8 was significantly higher than that of the control group (65.6% and 73% in comparison to 2.2% and 12%). In the pre-vaccine and post-vaccine (after 6, 7, 12 and 13 months) verification, no significant difference between vaccinated individuals and controls was observed.


CONCLUSIONS
The differences between vaccinated and unvaccinated individuals 1 and 2 months following vaccination indicate seroconversion in the vaccinated individuals. For the age group of between 2 to 6 years of age, the bactericidal activity acquired decline quickly, as, after 6 months, differences between this group and the control group are no longer observed.
Delgado Torralbo
E
E
Programa de Epidemiología Aplicada de Campo (PEAC), Instituto de Salud Carlos III. dseedt@csalud.junta-andalucia.es
Vazquez Moreno
J A
JA
García León
J
J
González Enríquez
J
J
Martínez Navarro
F
F
Berrón Morato
S
S
Mayoral Cortés
J M
JM
Rubin Gómez
M A
MA
Méndez Martínez
C
C
Cortés Majó
M
M
Chaves Caballero
M
M
Bernal González
M L
ML
D000907:Antibodies, Bacterial / Q000097:blood*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D022401:Meningococcal Vaccines / Q000276:immunology*; D009345:Neisseria meningitidis / Q000276:immunology*
D000907:Antibodies, Bacterial; D022401:Meningococcal Vaccines