TNF and Lassa fever: PBMCs from Sierra Leonean and Nigerian LF survivors were incubated overnight with rscVSVs encoding GP1, GP2 (Fig. 1A), NP (Fig. 1B), and overlapping fragments from each antigen (Fig. 1) and assessed for intracellular expression of interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α).