biostudies-literatureLaVergne SMFoundation for the National Institutes of Healthe0010882https://www.ebi.ac.uk/biostudies/studies/S-EPMC9731491biostudies-literatureUnknown16(11)<h4>Introduction</h4>Lassa virus is a priority pathogen for vaccine research and development, however the duration of cellular immunity and protection in Lassa fever (LF) survivors remains unclear.<h4>Methods</h4>We investigated Lassa virus specific CD8+ T cell responses in 93 LF survivors. Peripheral blood mononuclear cells from these individuals were infected with recombinant vesicular stomatitis virus encoding Lassa virus antigens and virus specific T cell responses were measured after 18-hour incubation. Participants who had undetectable CD8+ T cell response underwent further analysis using a 10-day T cell proliferation assays to evaluate for low T cell precursor frequency.<h4>Results</h4>Forty-five of the 93 LF survivors did not have a Lassa virus specific CD8+ T cell response. Of thoPLoS neglected tropical diseasesExpansion of CD8+ T cell population in Lassa virus survivors with low T cell precursor frequency reveals durable immune response in most survivors.PMC97314911R01AI123535.HHSN272201400048CGrant DSOldstone MBAKanneh Lde la Torre JCSakabe SGarry RFSchieffelin JSLaVergne SMSullivan BMMomoh MBond NfalseExpansion of CD8+ T cell population in Lassa virus survivors with low T cell precursor frequency reveals durable immune response in most survivors.<h4>Introduction</h4>Lassa virus is a priority pathogen for vaccine research and development, however the duration of cellular immunity and protection in Lassa fever (LF) survivors remains unclear.<h4>Methods</h4>We investigated Lassa virus specific CD8+ T cell responses in 93 LF survivors. Peripheral blood mononuclear cells from these individuals were infected with recombinant vesicular stomatitis virus encoding Lassa virus antigens and virus specific T cell responses were measured after 18-hour incubation. Participants who had undetectable CD8+ T cell response underwent further analysis using a 10-day T cell proliferation assays to evaluate for low T cell precursor frequency.<h4>Results</h4>Forty-five of the 93 LF survivors did not have a Lassa virus specific CD8+ T cell response. Of tho2022-01-01T00:00:00Z2022 Nov2025-04-22T11:18:18.811Z2025-04-05T23:54:30.422ZS-EPMC97314913644176510.1371/journal.pntd.0010882