Conference Abstract | Volume 8, Abstract ELIC2025405 (Oral 079) | Published: 19 Aug 2025
Ephraim Ogbaini-Emovon1,&, David Wozniak2,3, Anke Thielebein2,3, Yemisi Ighodalo1,3, Thomas Olokor1, Rachael Omiunu1, Abubakar Taju1, Mette Hinrichs3, Jonas Müller2,3, Rita Esumeh1, Oluwasola Babatunde1, Paulson Ebhodaghe1, Ganiyu Igenegbale1, Rosemary Giwa1, Anieno Ekanem1, Nosa Akpede1, Donatus Adomeh1, Sylvanus Okogbenin1, Cyril Erameh1, Joseph Okoguale1, Danny Asogun1, George Akpede1, Mojeed Rafiu1, Kelly. Iraoyah1, Osahogie Ediawe1, Wilson Ovienria1, Peter Okokhere1, Ruben Agbons Eifediyi1, Stephan Günther2,3, Lisa Oestereich2,3
1Irrua Specialist Teaching Hospital, Irrua, Edo State, Nigeria, 2Bernhard-Nocht-Institute for Tropical Medicine (BNITM), Hamburg, Germany, 3German Center for Infection Research (DZIF), Partner site Hamburg, Lübeck, Borstel, Riems, Germany
&Corresponding author: Ephraim Ogbaini-Emovon, Irrua Specialist Teaching Hospital, Irrua, Nigeria, Email: epogbaini@yahoo.com
Received: 31 May 2025, Accepted: 09 Jul 2025, Published: 19 Aug 2025
Domain: Infectious Disease Epidemiology
Keywords: Lassa fever, Lassa virus, Immunoglobulin G, Neutralization tests
©Ephraim Ogbaini-Emovon et al. Journal of Interventional Epidemiology and Public Health (ISSN: 2664-2824). This is an Open Access article distributed under the terms of the Creative Commons Attribution International 4.0 License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Cite this article: Ephraim Ogbaini-Emovon et al., Insights into long-term antibody response in Lassa fever: A five-year follow-up study of Lassa fever survivors in Nigeria. Journal of Interventional Epidemiology and Public Health. 2025;8(ConfProC):00079. https://doi.org/10.37432/JIEPH-CONFPRO5-00079
Lassa fever (LF), a viral hemorrhagic fever caused by Lassa virus (LASV), remains a persistent public health threat in West Africa. Despite anecdotal reports of immunity following infection, no licensed vaccine or therapeutic exists. Understanding the immune response, especially the antibody dynamics in LF survivors, is essential for guiding vaccine development and public health interventions. This study aimed to assess long-term serologic responses, specifically the kinetics and neutralization capacity of antibodies, including cross-neutralization of LASV strains over 60 months post-convalescence.
This longitudinal, prospective study was conducted at Irrua Specialist Teaching Hospital in collaboration with the Bernhard Nocht Institute for Tropical Medicine (BNITM), Germany. A cohort of 159 LF survivors was followed for 60 months post-discharge. Sera were collected at up to 12 time points and assessed for anti-LASV IgG antibodies using ELISA (targeting glycoproteins (GP) and nucleoproteins (NP)). Neutralization assays using live virus were performed under BSL-4 conditions at BNITM.
IgG titers against LASV GP increased during late convalescence, while anti-NP IgG was detectable early during acute infection. Antibody levels remained high for up to five years. Sera demonstrated robust neutralizing activityagainst native LASV (Lineage II) and cross-neutralization against LASV Lineages II, III, IV, V, and VII. However, cross-neutralization was limited against Lineage V. Despite stable IgG titers, a late decline in neutralization capacity was observed.
LASV-specific antibodies persist in survivors for up to five years, with substantial neutralizing and cross-neutralizing activity against most LASV lineages, excluding Lineage V. However, a potential late decline in functional neutralization capacity was noted. An extended follow-up cohort is underway to further evaluate long-term immunity and implications for vaccine strategies.
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