Pneumococcal serotype-specific antibodies persist through early childhood after infant immunization: follow-up from a randomized controlled trial

PLoS One. 2014 Mar 11;9(3):e91413. doi: 10.1371/journal.pone.0091413. eCollection 2014.

Abstract

Background: In a previous UK multi-center randomized study 278 children received three doses of 7-valent (PCV-7) or 13-valent (PCV-13) pneumococcal conjugate vaccine at 2, 4 and 12 months of age. At 13 months of age, most of these children had pneumococcal serotype-specific IgG concentrations ≥ 0.35 µg/ml and opsonophagocytic assay (OPA) titers ≥ 8.

Methods: Children who had participated in the original study were enrolled again at 3.5 years of age. Persistence of immunity following infant immunization with either PCV-7 or PCV-13 and the immune response to a PCV-13 booster at pre-school age were investigated.

Results: In total, 108 children were followed-up to the age of 3.5 years and received a PCV-13 booster at this age. At least 76% of children who received PCV-7 or PCV-13 in infancy retained serotype-specific IgG concentrations ≥ 0.35 µg/ml against each of 5/7 shared serotypes. For serotypes 4 and 18C, persistence was lower at 22-42%. At least 71% of PCV-13 group participants had IgG concentrations ≥ 0.35 µg/ml against each of 4/6 of the additional PCV-13 serotypes; for serotypes 1 and 3 this proportion was 45% and 52%. In the PCV-7 group these percentages were significantly lower for serotypes 1, 5 and 7F. A pre-school PCV-13 booster was highly immunogenic and resulted in low rates of local and systemic adverse effects.

Conclusion: Despite some decline in antibody from 13 months of age, these data suggest that a majority of pre-school children maintain protective serotype-specific antibody concentrations following conjugate vaccination at 2, 4 and 12 months of age.

Trial registration: ClinicalTrials.gov NCT01095471.

Publication types

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

MeSH terms

  • Antibodies, Bacterial / blood
  • Antibodies, Bacterial / immunology*
  • Child
  • Child, Preschool
  • Female
  • Follow-Up Studies
  • Humans
  • Immunization, Secondary
  • Immunoglobulin G / blood
  • Immunoglobulin G / immunology
  • Male
  • Pneumococcal Infections / immunology*
  • Pneumococcal Infections / prevention & control*
  • Pneumococcal Vaccines / administration & dosage
  • Pneumococcal Vaccines / immunology
  • Serogroup
  • Streptococcus / classification
  • Streptococcus / immunology*
  • Streptococcus pneumoniae / immunology
  • United Kingdom
  • Vaccination

Substances

  • 13-valent pneumococcal vaccine
  • Antibodies, Bacterial
  • Immunoglobulin G
  • Pneumococcal Vaccines

Associated data

  • ClinicalTrials.gov/NCT01095471

Grants and funding

This work was supported by Pfizer Vaccine Research and the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre with support from the NIHR Thames Valley and Hampshire and Isle of Wight Comprehensive Local Research Networks, NIHR South West Medicines for Children Network (MCRN), London and South East MCRN and Southampton NIHR Wellcome Trust Clinical Research Facility. JT was supported by an ESPID Fellowship Award. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.