Aim:
  • To better understand the functional immune response and the relationship between different measures of the immune response and the bacteriologic and clinical efficacy of new and novel schedules of pneumococcal conjugate vaccines (PCVs) in high risk Indigenous infants.
Objectives:

In Australian Indigenous infants enrolled in our NHMRC-funded randomised controlled trial, PREV-IX_COMBO vaccines for healthy ears, and receiving standard or novel schedules of different pneumococcal conjugate vaccines (Synflorix and/or Prevenar13), to:

  1. measure and compare the functionality (opsonophagocytic activity, OPA) of pneumococcal serotype-specific antibodies in response to three PCV schedules in PREV-IX_COMBO
  2. compare the pneumococcal serotype-specific OPA with Enzyme ImmunoAssay (EIA) IgG
  3. correlate these measures of immune response with bacteriologic and clinical outcomes.

To test the hyptheses that the functionality (OPA) of antibodies is a more informative and accurate measure of the protective immune response to vaccines than the concentration of antibodies measured by the EIA. Specifically, the functionality of vaccine-induced antibodies, measured by OPA is better correlated with protection from nasopharyngeal colonisation; is better correlated with protection from otitis media, and is superior for Synflorix compared to Prevenar13.

Chief investigators: