Comparison of EBOV GP IgG antibody reactivity: Results from two immunoassays in the Democratic Republic of the Congo

Authors: MERRITT, SYDNEY - University Of California (UCLA); HALBROOK, MEGAN - University Of California (UCLA); KOMPANY, JEAN PAUL - Institute National Research Biomedical; CHANDRASEKARAN, PRABHA - National Instiute Of Allergy And Infectious Diseases (NIAID, NIH); SMITH, OLIVIA - University Of Hawaii; HOFF, NICOLE - University Of California (UCLA); TAMBU, MERLY - Institute National Research Biomedical; MARTIN, SKYLAR - University Of California (UCLA); WONG, TERI ANN - University Of Hawaii; JARRA, AMIE - National Instiute Of Allergy And Infectious Diseases (NIAID, NIH); BARRALL, ANGELICA - University Of California (UCLA); MUSENE, KAMY - University Of California (UCLA); BEYA, MICHAEL - University Of Kinshasa; ORR, ROBERT - Food And Drug Administration(FDA); MYERS, TODD - Food And Drug Administration(FDA); MACGILL, TRACY - Food And Drug Administration(FDA); Hensley, Lisa; MUYEMBE-TAMFUM, JEAN-JACQUES - Institute National Research Biomedical; KABA, DIDINE - University Of Kinshasa; BERRY, IRINA - National Instiute Of Allergy And Infectious Diseases (NIAID, NIH); MBALA-KINGBENI, PLACIDE - Institute National Research Biomedical; LEHRER, AXEL - University Of Hawaii; RIMOIN, ANNE - University Of California (UCLA)

Submitted to: Journal of Virological Methods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/31/2025
Publication Date: 7/1/2025
Citation: Merritt, S., Halbrook, M., Kompany, J., Chandrasekaran, P., Smith, O.A., Hoff, N.A., Tambu, M., Martin, S.A., Wong, T., Jarra, A., Barrall, A.L., Musene, K., Beya, M., Orr, R., Myers, T., Macgill, T., Hensley, L.E., Muyembe-Tamfum, J., Kaba, D., Berry, I.M., Mbala-Kingbeni, P., Lehrer, A.T., Rimoin, A.W. 2025. Comparison of EBOV GP IgG antibody reactivity: Results from two immunoassays in the Democratic Republic of the Congo. Journal of Virological Methods. 336. https://doi.org/10.1016/j.jviromet.2025.115154.
DOI: https://doi.org/10.1016/j.jviromet.2025.115154

Interpretive Summary: Ebola is a severe disease which has had sporadic outbreaks across Western and Central Africa. Due to the high consequence nature of the disease, new tools to investigate how well vaccines work, or how protected survivors of this disease may be, are important for science and human health. While there is an existing assay (the gold-standard) which looks at antibody reactivity to one target of the larger Ebola virus, we sought to assess how a new multi-target assay (which includes the same target) compares to this industry standard. We show high correlation between the reactivity results across both assays. The populations tested included known Ebola survivors, as well as health care workers, community controls and individuals who received the vaccine in 2018.

Technical Abstract: Ebola virus (EBOV) is a highly infectious pathogen, and its long-term consequences continue to be investigated. With its high fatality rate and potential for reinfection or latent infection, continued development of research tools is of utmost importance. Using a cohort (n = 503) of existing bio-banked specimens from the Democratic Republic of the Congo (DRC) two EBOV glycoprotein (GP) immunoglobulin G (IgG) antibody-detection assays were compared: the gold-standard Filovirus Animal Non-Clinical Group (FANG) and a Multiplex bead-based Immunoassay (MIA) with seven pan-filoviral targets. As not all immunoassays have been shown to detect a vaccine-induced immune response, and previous EBOV serosurveillance has been primarily conducted with singleplex technology, this MIA was assessed as an additional resource. Among the cohort, as sample seroreactivity increased, assay correlation increased (r2=0.80). Correlation was sustained among sub-populations of the cohort—in detecting natural immunity among survivors and vaccine-derived responses. Additionally, when results were binarized by seroreactivity, there was high correlation between the two assays (kappa=0.70) with 71 serodiscordant samples. These data indicate that the MIA is an apt alternative to the singleplex FANG assay in detecting relative seroreactivity and can be used as a potential tool for widespread pan-filovirus serosurveillance in the DRC and similar contexts.