Antibody avidity was assessed in day 70 and day 62 serum from mice immunized with viral-vectors (
Fig. 2B) and 2.5 μg protein-in-adjuvant vaccines respectively ( Fig. 2C). Avidity of serum IgG responses was assessed by NaSCN-displacement ELISA and is reported as the molar concentration of NaSCN required to reduce the OD 405 to 50% of that without NaSCN. The isotype profiles (IgG1 and IgG2a) of serum antibody responses were also assessed by ELISA for the same time-points for the viral-vector immunized mice ( B) and the protein-in-adjuvant immunized mice ( C) (n.d., not detected). BALB/c mice (n = 5 per group) received Pfs25-IMX313 vaccines via the i.m. route in different combination of regimes. A–M and A–P prime-boost regime were 8 weeks apart and P–P was 4 weeks apart. Two weeks after the boost vaccination in each group, serum samples were collected and the total IgG response was measured using a Pfs25 standardized ELISA ( D). BALB/c mice (n = 6 per group) received prime-boost vaccinations (2 immunisations, 3 weeks apart) of Pfs25-IMX313 protein-nanoparticle formulated in Alhydrogel, LMQ or MF59. Three weeks after each vaccination, serum samples were collected and the total IgG response was measured using Pfs25 standardized ELISA ( E). Mean with SEM are depicted and individual data are shown for all figures. For A, B and C, Mann-Whitney test was performed **p < 0.01. For D and E, Kruskal-Wallis test followed by Dunn’s multiple comparison post-test was performed *p < 0.05, **p < 0.01, ***p < 0.001.