Current research for a vaccine against Lassa hemorrhagic fever virus

Warner, Bryce M; Safronetz, David; Stein, Derek R

The activation of LASV-specific T cells is thought to play an important role during infection as LF development results in the depletion of T cells in NHP models. 13, 24 Both CD4 and CD8 T cells can be activated early following LASV infection, and LASV-NP-specific memory CD4 T cells have been detected in patients up to 6 years following infection. 25, 26 The activation of T cells during LASV infection requires APC activation and maturation for efficient antigen processing and presentation. As with infection of APC, infection with MOPV in vitro can induce a much stronger T-cell response than infection with LASV, again indicating that pathogenic LASV infection likely requires suppression of innate and adaptive immune responses. 27 The role of humoral responses during LASV infection is less clear. Antibody responses against LASV are typically weak with low levels of IgM and IgG produced during early infection. Antibodies are thought by many to not contribute to natural recovery, as neutralizing antibodies are not produced at high levels. However, the role of antibodies in protection against LF is still not fully clear and mechanisms such as antibody-dependent cell-mediated cytotoxicity, complement fixation/activation, and opsonization may potentially play a role in protection from disease.