[Testing of antibodies against serogroup C Neisseria meningitidis by serum bactericidal assay in healthy population, Liaoning province].

Objective: To test the serum antibodies from healthy population by Serum Bactericidal Assay (SBA), in order to evaluate the level of protective antibodies against serogroup C Neisseria meningitidis in Liaoning province.

Methods: 240 serum samples were selected from eight age-group randomly. Serogroup C vaccine candidate strain (C11) and the prevail serogroup C strain (053442) were used for SBA.

Results: 48.33% of 240 serum samples were positive (titer > or = 1:2) to C11 vaccine strain. Protective rate of SBA was 35.83% (titer > or = 1:8), in which, > or = 6 years old were 13.33%, 7-19 years old was 61.67%, 20-39 years old were 46.67% and > or = 40 years old were 63.33%. Rate of SBA to 053442 was lower than that to C11 in the group over 15 years old by statistic analysis.

Conclusion: Population under 6 years old showed lower SBA capacities. With the implemention of Expanded Program on Immunization, children under 3 years old should be considered how to give them meningococcal vaccine in order to improve the titer of antibodies against Neisseria meningitidis serogroup C.