Clinical Evaluation of Group A and Group C Meningococcal Polysaccharide Vaccines in Infants and Children

摘要

A cohort of infants, previously immunized once or twice between 3-12 months of age with groups A and C meningococcal polysaccharide vaccines, received boosters at 2 and 5 and one half years of age with bivalent A/C vaccine. Antibody concentrations were measured by a radioactive antigen binding assay. Anti-A and anti-C concentrations were 5.59 and 2.86 micrograms/ml, respectively, by 4 years of age. After booster immunization at 5 and one half years of age, anti-A and anti-C antibody may be achievable throughout early childhood by routine immunization with the A vaccine. Although the group C vaccine is effective in epidemic control, the rapid decline of anti-C concentration following immunization of young children suggests that protection may not be long-lasting.