title: [Analysis for protection rate and antibody levels of epidemic cerebrospinal meningitis among children aged between 3-23 months in Liuzhou, in 2012].
abstract: Objective:To understand the level of bactericidal antibodies againstNeisseria meningitidisand their rate of protection in children aged between 3 and 23 months, in Liuzhou, in 2012.Methods:Convenience sampling was performed in Liujiang, Rong'an and Sanjiang Counties from May through August, 2012. The inclusion criteria for 603 subjects were: Children aged between 3 and 23 months; no history of meningococcal meningitis; no vaccination againstNeisseria meningitidisserogroup C; more than 30 days from the last vaccination againstNeisseria meningitidisserogroup A. Demographic information and immunization history of the subjects were obtained using questionnaires. Venous blood samples (2.0 ml each) were collected and levels ofNeisseria meningitidesantibodies determined using a Serum Bactericidal Assay (SBA). The geometric mean titer (GMT) of serum bacterial antibodies was positive when it was greater than or equal to 1∶2 and protective when greater than 1∶8. Chi-square and Fisher's exact tests were used to compare differences in the positive and protective rates of serum antibodies ofNeisseria meningitidisserogroup A andNeisseria meningitidisserogroup C, among children with different demographic characteristics. Kruskal-WallisHtest was used to compare differences in the GMT of serum antibodies ofNeisseria meningitidisserogroup A andNeisseria meningitidisserogroup C, among children with different demographic characteristics.Results:Of 603 subjects, 325 (53.9%) were female and 278 (46.1%) were male; 276 (45.8%), 143 (23.7%) and 184 (30.5%) subjects were administered, respectively, no treatment, 1 dose vaccine and 2 doses vaccine. The GMT of serum antibodies against group ANeisseria meningitidiswas 1∶1.11, the positive rate was 7.6% (46) and the protective rate was 2.0% (12). The GMT of antibodies in children receiving 1 vaccine dose was 1∶1.16 and the protective rate was 3.5% (5), both values higher than those in children receiving 2 vaccine doses (GMT: 1∶1.2, protective rate: 3.5% (5)). However, these differences were not statistically significant (GMT:H=0.64,P=0.728; protective rate: Fisher's exact test,P=0.080). The GMT of antibodies in children receiving 1 and 2 doses ofmeningococcal polysaccharidevaccines were 1∶1.12 and 1∶2.30, respectively (≤180 d). The GMT of serum antibodies for group Cmeningococcalvaccine was 1∶1.18 and its positive and protective rates were 14.6% (88) and 2.2% (13), respectively.Conclusion:Children aged between 3 and 23 months are susceptible toNeisseria meningitidisgroups A and C. The immune effectiveness of group Ameningococcal polysaccharidevaccine is relatively poor in this age group and their antibody levels decreased rapidly.
authors.affiliation: Liuzhou Center for Disease Control and Prevention, Liuzhou 545007, China.
authors.forename: X L
authors.initials: XL
authors.lastname: Cui
authors.forename: X
authors.initials: X
authors.lastname: Wu
authors.forename: M Q
authors.initials: MQ
authors.lastname: Li
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008585:Meningitis, Meningococcal; D022401:Meningococcal Vaccines; D009345:Neisseria meningitidis / Q000302:isolation & purification*; D038381:Neisseria meningitidis, Serogroup A; D038542:Neisseria meningitidis, Serogroup C / Q000276:immunology; D011135:Polysaccharides, Bacterial; D015610:Serum Bactericidal Test; D014611:Vaccination
chemical_list: D000907:Antibodies, Bacterial; D022401:Meningococcal Vaccines; D011135:Polysaccharides, Bacterial; C043226:meningococcal group A polysaccharide