Comparative study of serum bactericidal activity to serogroup C and serogroup A polysaccharide meningococcal vaccination

Abstract number: R2547

Siadat S.D., Rezaei N., Norouzian D., Aghamohammadi A., Ahmadi H., Tabaraie B., Nejati M.

Objective: The polysaccharide vaccine against meningococcus serogroups A and C was the prototype vaccine for this infection, which is safe, inexpensive and effective against the serotypes A and C. Serum bactericidal antibody (SBA) assay, an antibody-mediated complement-dependent method, is the gold standard surrogate of protection for Neisseria meningitidis. This study was performed to compare serum bactericidal activity to serogroup C and serogroup A after polysaccharide meningococcal vaccination.

Methods: Sixteen subjects (36 patients with primary immunodeficiency diseases and 24 healthy controls) were vaccinated with meningococcal polysaccharide vaccine A + C. The SBA assay was performed according to the World Health Organization (WHO) expert Committee on Biological Standardization procedure. Bactericidal antibody response to N. meningitidis serogroups A and C in the sera of all subjects were compared before and 3 weeks after vaccination. The geometric mean titer (GMT) were calculated and compared.

Results: Following vaccination, the serum bactericidal antibody GMT against N. meningitidis serogroup A and serogroup C were significantly increased compared to the pre-vaccination level in both patient and control groups. The serum bactericidal GMT pre- and post-vaccination against serogroup C were 1.49 and 12.1 while against serogroup A were 1.32 and 16.25. Comparative studies of the serum bactericidal GMT per-vaccination was not revealed any significant difference between bactericidal activity to N. meningitidis serogroup A and serogroup C (P= 0.207), whereas the serum bactericidal GMT post-vaccination to serogroup A were significantly higher than the serogroup C (P= 0.006).

Conclusion: The high level of bactericidal antibody response to N. meningitidis serogroups A is seemed to be due to differences protective efficacy of serogroup A polysaccharide (89–100%) in comparison to serogroup C polysaccharide (85%) in clinical trials.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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