The ability of IVTT products to stimulate an antigen-specific antibody response was also determined. Sera from mice (n = 5/group) primed with VR2516 PyCSP plasmid DNA and boosted in vivo with rPyCSP IVTT purified using NI-NTA resin plus Alum were evaluated by ELISA against synthetic peptide representing the recombinant PyCSP protein. Data demonstrated that in vivo boosting with PyCSP IVTT products significant boosted antigen-specific antibody responses relative to responses induced by PyCSP plasmid DNA in the absence of boosting ( Figure 5 ).