Safety, immunogenicity, and induction of immunologic memory by a serogroup C meningococcal conjugate vaccine in infants: A randomized controlled trial

JAMA. 2000 Jun 7;283(21):2795-801. doi: 10.1001/jama.283.21.2795.


Context: Neisseria meningitidis is a common cause of meningitis and septicemia in infants worldwide. Whether a meningococcal C conjugate vaccine protects infants against the serogroup C strain is unknown.

Objectives: To determine whether a meningococcal C conjugate vaccine is safe and immunogenic and induces immunologic memory in infants.

Design: Single-center, double-blind, randomized controlled trial in 1995 and 1996.

Setting: Community, Oxfordshire, England.

Participants: One hundred eighty-two healthy infants.

Interventions: Participants were randomly assigned to receive vaccination with 0. 5-mL doses of 1 of 2 lots of meningococcal C conjugate vaccine (groups 1 and 2; n=60 in each group) or a hepatitis B control vaccine (group 3; n=62), administered with routine immunizations at 2, 3, and 4 months of age. Approximately half of each group received meningococcal C conjugate vaccine and half received plain meningococcal polysaccharide vaccine (MPS) at 12 months of age.

Main outcome measures: Serum antibodies to meningococcal C polysaccharide, assayed by enzyme-linked immunosorbent assay, and serum bactericidal activity (SBA), at 2, 3, 4, 5, 12, and 13 months of age; local and systemic reactions, recorded for 6 days after each vaccination, compared by intervention group.

Results: Meningococcal C conjugate vaccine was well tolerated. After 3 doses, children in groups 1 and 2 achieved significantly higher meningococcal C IgG geometric mean concentrations (21 and 17 U/mL, respectively, vs 0.20 U/mL; P<.001) and SBA titers (629 and 420, respectively, vs 4.1; P<. 001) than controls. At 12 months, antibody concentrations had decreased in all groups but remained significantly higher in children vaccinated with meningococcal C conjugate vaccine (SBA, 24 and 16 in groups 1 and 2, respectively, vs 4.2 in group 3; P<.001). Following vaccination with MPS at 12 months of age, SBA in the meningococcal C conjugate vaccine group was significantly higher than in controls (SBA, 789 vs 4.5; P<.001).

Conclusions: Our data indicate that meningococcal C conjugate vaccine is safe and immunogenic and results in immunologic memory when given with other routinely administered vaccines to infants at 2, 3, and 4 months of age. JAMA. 2000;283:2795-2801

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Antibodies, Bacterial / biosynthesis
  • Antibodies, Bacterial / immunology
  • Bacterial Vaccines / administration & dosage
  • Bacterial Vaccines / immunology*
  • Blood Bactericidal Activity
  • Double-Blind Method
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Humans
  • Immunization, Secondary
  • Immunoglobulin G / immunology
  • Immunologic Memory
  • Infant
  • Male
  • Meningococcal Vaccines
  • Neisseria meningitidis / classification
  • Neisseria meningitidis / immunology*
  • Probability
  • Serotyping
  • Vaccines, Conjugate / administration & dosage
  • Vaccines, Conjugate / immunology*


  • Antibodies, Bacterial
  • Bacterial Vaccines
  • Immunoglobulin G
  • Meningococcal Vaccines
  • Vaccines, Conjugate
  • serogroup C meningococcal conjugate vaccine