Fig. 4.

Prime–boost vaccination with two administrations enhances antibody production for all treatments, while SNA immunization is highest. Levels of (A) binding and (B) neutralizing antibodies on either day 14 (prime only on day 0, sera collection on day 14) or on day 28 (prime on day 0, boost on day 14, sera collection on day 28). Graphs show mean and SD for n = 3 to 6 per group. Analysis was done using a two-way ANOVA followed by a Tukey’s multiple comparisons test. Only significant comparisons are shown. *P < 0.05; **P < 0.01.