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May 15, 1996

Safety and Immunogenicity of a Serogroups A/C Neisseria meningitidis Oligosaccharide—Protein Conjugate Vaccine in Young Children: A Randomized Controlled Trial

Author Affiliations

From the UCLA Center for Vaccine Research, Harbor-UCLA Medical Center, Torrance, Calif (Drs Lieberman, Chiu, and Ward, Mss Partridge and Chang, and Mr Chiu); Kaiser Permanente, Southern California Region, Bellflower (Dr Wong); and the Childhood and Respiratory Diseases Branch, Division of Bacterial and Mycotic Diseases, Centers for Disease Control and Prevention, Atlanta, Ga (Dr Carlone and Ms Gheesling). Dr Chiu is now with the Department of Paediatrics. Queen Mary Hospital, University of Hong Kong.

JAMA. 1996;275(19):1499-1503. doi:10.1001/jama.1996.03530430043037

Objective.  —To assess the safety and immunogenicity of a bivalent serogroups A/C meningococcal oligosaccharide—protein conjugate vaccine compared with the licensed meningococcal polysaccharide vaccine.

Design.  —Randomized controlled trial.

Study population.  —Ninety healthy 18- to 24-month-old children who were seen at a southern California Kaiser Permanente clinic.

Interventions.  —Vaccination with either the meningococcal conjugate vaccine (at 1 of 2 dosages) or the polysaccharide vaccine, with 2 doses given 2 months apart.

Main Outcome Measures.  —Immune response to each vaccine dose as determined by measurement of serogroup-specific total antibodies by enzyme-linked immunosorbent assay (ELISA) and by assessment of serum bactericidal activity.

Results.  —Both vaccines appeared to be safe, and nearly all children responded with greater than 4-fold increases in antibody levels. The 2 dosages of the conjugate vaccine induced similar antibody responses; therefore, the data for the 2 conjugate vaccine groups were combined. Following 2 doses, ELISA antibody levels against group C meningococcus were significantly higher in conjugate vaccine recipients than in polysaccharide vaccine recipients (16.66 μg/mL vs 8.31 μg/mL; P<.001), but antibody levels against group A were not significantly different (22.75 μg/mL vs 21.24 μg/mL; P=.70). The serum bactericidal assays showed striking differences between the conjugate and polysaccharide vaccine groups. Geometric mean serum bactericidal titers were significantly higher in conjugate vaccine recipients (755.6 vs 37.6 for group A, P<.001; 3197.9 vs 11.4 for group C, P<.001).

Conclusions.  —The immune response induced by this meningococcal oligosaccharide—protein conjugate vaccine was qualitatively different from that induced by the polysaccharide vaccine, and the antibodies it elicited provided greater functional activity.(JAMA. 1996;275:1499-1503)