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Hyporesponsiveness to re-challenge dose following pneumococcal polysaccharide vaccine at 12 months of age, a

F M Russell1, J R Carapetis, A Balloch

  • 1Centre for International Child Health, Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Victoria, Australia. fmruss@unimelb.edu.au

Vaccine
|March 9, 2010
PubMed

Insights

Giving infants the 23-valent pneumococcal polysaccharide vaccine (23vPPS) at 12 months impaired their immune response to a later pneumococcal conjugate vaccine (PCV) challenge. This suggests a suboptimal vaccination strategy for pneumococcal protection in infants.

Area of Science:

  • Immunology
  • Vaccinology
  • Pediatrics

Background:

  • Evaluating the immunological impact of the 23-valent pneumococcal polysaccharide vaccine (23vPPS) in infants previously vaccinated with the 7-valent pneumococcal conjugate vaccine (PCV).
  • Assessing the effect of varying PCV infant doses on the response to a subsequent 23vPPS challenge.

Purpose of the Study:

  • To determine the immunological consequences of administering 23vPPS at 12 months in infants with different infant PCV vaccination histories.
  • To analyze the impact of 23vPPS on the immune response to a subsequent pneumococcal polysaccharide vaccine (mPPS) challenge.

Main Methods:

  • A randomized trial involving 552 Fijian infants stratified by ethnicity.
  • Infants received zero, one, two, or three PCV doses, followed by either 23vPPS or no vaccine at 12 months.
  • All infants received a small dose of 23vPPS (mPPS) at 17 months, with serum samples collected pre- and post-vaccination.

Main Results:

  • Antibody concentrations were higher at 17 months in infants who received 23vPPS at 12 months.
  • However, infants who did *not* receive the 12-month 23vPPS showed a significantly higher antibody response to the mPPS challenge for all PCV serotypes.
  • A prior 23vPPS dose at 12 months was associated with a diminished immune response to the subsequent mPPS challenge across all 23 serotypes.

Conclusions:

  • While 23vPPS at 12 months boosts antibody levels, it impairs the immune system's ability to respond effectively to a subsequent pneumococcal vaccine challenge.
  • This finding suggests that the timing and sequence of pneumococcal vaccines (PCV and 23vPPS) significantly influence infant immune responses and may necessitate strategy adjustments.
Abstract

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