Seroconversion and duration of immunity after vaccination against group C meningococcal infection in young children.
An increase in the incidence of group C meningococcal disease was observed in the Murcia Region (Spain) during 1996-1997. In September 1997, a massive vaccination campaign was implemented among the population aged 18 months to 19 years. The aim of this study was to assess the seroconversion rate of children aged 18-59 months and the persistence of immune response 1 year after vaccination. A total of 296 children were included. Blood samples were obtained before vaccination and 1 month and 1 year after vaccination. Three point seven percent of the children had bactericidal antibody titres of >/=1:8 before vaccination. One month after vaccination seroconversion was 63.7%, with a growing trend related to age at vaccination (p<0.0001). The increase in antibody titres was shown to be quantitatively greater above the age of 36 months (p<0.0001). One year after vaccination only 4.3% of the children who initially seroconverted still had bactericidal activity. Seroconversion in children under 5 increases with age but antibodies decline rapidly in the year following vaccination.
Espín Ríos
I
I
Directorate General of Public Health, 300008 Murcia, Spain.
García-Fulgueíras
A
A
Navarro Alonso
J A
JA
Vazquez Moreno
J
J
Rodriguez Gonzalez
T
T
Navarro Sánchez
C
C
Pérez-Flores
D
D
D000942:Antigens, Bacterial / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D008297:Male; D008589:Meningococcal Infections / Q000517:prevention & control*; D009345:Neisseria meningitidis / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D012307:Risk Factors; D013030:Spain
D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D011135:Polysaccharides, Bacterial; C037676:meningococcal group C polysaccharide