Opsonophagocytic activity following a reduced dose 7-valent pneumococcal conjugate vaccine infant primary series and 23-valent pneumococcal polysaccharide vaccine at 12 months of age

Abstract

Opsonophagocytic activity (OPA) was measured following reduced infant doses of 7-valent pneumococcal conjugate vaccine (PCV-7) with or without 23-valent pneumococcal polysaccharide vaccine (PPV-23) at 12 months, and subsequent re-exposure to a small dose of pneumococcal polysaccharide antigens (mPPS) at 17 months. Fijian infants were randomized to receive 0, 1, 2, or 3 PCV-7 doses. Half received PPV-23 at 12 months and all received mPPS at 17 months. OPA was performed on up to 14 serotypes. Three and 2 PCV-7 doses resulted in similar OPA for most PCV-7 serotypes up to 9 months and for half of the serotypes at 12 months. A single dose improved OPA compared with the unvaccinated group. PPV-23 significantly improved OPA for all serotypes tested but in general, was associated with diminished responses following re-challenge.

Trial registration: ClinicalTrials.gov NCT00170612.

Copyright © 2010 Elsevier Ltd. All rights reserved.

Figures

Figure 1. Pre- and one month post-mPPS OPA titer for serotypes 4 and 6B, in those that did (+) and did not (o) receive PPV-23 at 12 months of age. Data from infants receiving 0, 1, 2, or 3 PCV-7 doses have been combined in these graphs

Footnote: A 45-degree line, which indicates no change before and after the re-challenge (mPPS), is superimposed. The pre- and post-mPPS OPA titer of those who received PPV-23 at 12 months mostly fell along the 45-degree line, indicating no response to mPPS, except for serotypes 1 and 5. In contrast, most children who did not receive PPV-23 had an increase in OPA titer, as indicated by the data points falling above the 45-degree line

Figure 1. Pre- and one month post-mPPS OPA titer for serotypes 4 and 6B, in those that did (+) and did not (o) receive PPV-23 at 12 months of age. Data from infants receiving 0, 1, 2, or 3 PCV-7 doses have been combined in these graphs

Footnote: A 45-degree line, which indicates no change before and after the re-challenge (mPPS), is superimposed. The pre- and post-mPPS OPA titer of those who received PPV-23 at 12 months mostly fell along the 45-degree line, indicating no response to mPPS, except for serotypes 1 and 5. In contrast, most children who did not receive PPV-23 had an increase in OPA titer, as indicated by the data points falling above the 45-degree line