- To better understand humoral immunity following Ebolavirus infection, a serological study of the humoral immune response against the individual viral proteins of Sudan ebolavirus (Gulu) in human survivors was performed. An ELISA assay specific for full-length recombinant viral proteins NP, VP30, VP40 and GP1-649 (GP lacking the transmembrane domain) of Sudan ebolavirus (Gulu) was employed as well as a plaque reduction neutralization test. Serum samples from human survivors, collected up to ten years following recovery, were screened and analyzed. Results demonstrate that samples obtained ten years following infection contain virus specific antibodies and can neutralize virus. Neutralization correlates well with immunoreactivity against the viral proteins NP, VP30 and GP1-649. Sera from individuals who died, or with no documented infection but immunoreactive to Ebolavirus, did not neutralize. This work provides insight into the duration, profile of immunoreactivity, and neutralization capacity of the humoral immune response in Ebolavirus survivors.