Skip Navigation LinksHome > June 2004 - Volume 23 - Issue 6 > Protective Activity of Group C Anticapsular Antibodies Elici...
Pediatric Infectious Disease Journal:
Original Studies

Protective Activity of Group C Anticapsular Antibodies Elicited in Two-Year-Olds by an Investigational Quadrivalent Neisseria meningitidis-Diphtheria Toxoid Conjugate Vaccine

Granoff, Dan M. MD; Harris, Shannon L. PhD

Collapse Box


Background: Quadrivalent capsular group A, C, Y and W-135 meningococcal conjugate (MC-4) vaccines are under development

Objective: Predict efficacy of an investigational MC-4 vaccine in 2-year-old children for prevention of group C disease.

Design: Measurement of group C antibody concentrations, avidity and bactericidal and passive protective activity in sera from 2-year-olds given 1 dose of MC-4 vaccine (N = 30) and 3-year-olds (N = 30) and adults (N = 26) given 1 dose of meningococcal polysaccharide (MPS-4) vaccine.

Results: One month after vaccination, the geometric mean anticapsular antibody concentration of children given MC-4 vaccine (3.1 μg/ml) was lower than that of control children (5.1 μg/ml; P < 0.04) or adults immunized with MPS-4 vaccine (22.9 μg/ml; P < 0.001). However, the percent of sera with protective bactericidal titers of ≥1/4 was higher in children given MC-4 vaccine (50%, versus 17% in children given MPS-4 vaccine; P < 0.02) and was not significantly different from that of immunized adults (65%). In children, the mean antibody avidity at 1 month was higher in the MC-4 group (22 nM−1 versus 16 nM−1 in the MPS-4 group; P = 0.002), and at 6 months increased in the MC-4 group (28 nM−1; P < 0.001), but not in the MPS-4 vaccine group (17 nM−1). Higher avidity antibody gave greater passive protection in the infant rat bacteremia model than did lower avidity antibody (P < 0.03).

Conclusions: Although MPS-4 vaccine elicited higher group C serum antibody concentrations in 3-year-olds than did MC-4 vaccine in 2-year-olds, the higher antibody avidity after MC-4 vaccine resulted in higher bactericidal and passive protective activity.

© 2004 Lippincott Williams & Wilkins, Inc.


Article Tools


Article Level Metrics

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.