Models of RNA virus evolution and their roles in vaccine design

Ojosnegros, Samuel; Beerenwinkel, Niko

The attenuated virus is still competent for replication and it retains the ability to infect host cells. For this reason, LAVs can elicit different effector mechanisms of the immune system. The intracellular replication of the virus can stimulate cytotoxic CD8 + cells because they can be presented by major histocompatibility complex (MHC) class I molecules. Particles released outside the cell can also be presented by class II MHC molecules [39] . After immunization with the LAV, the immune system is exposed to multiple antigens of the virus in its native conformation. Once the infection with the LAV is cleared from the organism, the virus-specific immune cells remain as memory cells in the host. A future challenge with the wild type virus will trigger the correct response, i.e., predominantly cellular response or predominantly humoral response. LAVs are considered the most successful vaccines because the efficient and multiple stimulation of the immune system typically induces a potent and durable response [38] .