Bead-based suspension array for simultaneous detection of antibodies against the Rift Valley fever virus nucleocapsid and Gn glycoprotein.

A multiplex bead-based suspension array was developed that can be used for the simultaneous detection of antibodies against the surface glycoprotein Gn and the nucleocapsid protein N of Rift Valley fever virus (RVFV) in various animal species. The N protein and the purified ectodomain of the Gn protein were covalently linked to paramagnetic Luminex beads. The performance of the resulting multiplex immunoassay was evaluated by testing a comprehensive and well-characterized panel of sera from sheep, cattle and humans. The suitability of this multiplex immunoassay to differentiate infected from vaccinated animals (DIVA) was investigated by testing sera from lambs vaccinated with a paramyxovirus vaccine vector expressing the RVFV surface glycoproteins Gn and Gc. The results suggest that the bead-based suspension array can be used as a DIVA assay to accompany several recently developed experimental vaccines that are based on RVFV glycoproteins, and are devoid of the N protein.