Figure 7.

Antibody responses following vaccination. Mice (n = 25–31 mice per group) were vaccinated with PBS (Mock), PCV7, PPV23 or live attenuated vaccines deleted for caxP or ftsY on either a type 2 (D39ΔcaxP, D39ΔftsY) or type 19F (BNH97ΔcaxP, BNH97ΔftsY) background.

A–D  Serum was tested by ELISA using whole pneumococci as antigens from strains (A) BHN97, (B) D39x, (C) TIGR4 or (D) T4R (unencapsulated version of TIGR4). The antibody dilution utilized was 1:450 for all strains. Mean OD₄₅₀ values ± SEM are displayed. * = Significant difference p < 0.05 by ANOVA compared to the mock and PPV23 groups; ** = significant difference compared to all other groups. PCV7 contains type 4 and 19F antigens but not type 2; PPV23 contains all three antigens. Data representative of at least 25 mice per group, performed in duplicate.