Researchers at the Wistar Institute and Emory University examined why therapeutic vaccines often fail to provide adequate results. Their preclinical studies suggest that T cells in chronically infected mice respond poorly to vaccines, failing to proliferate as they should.
In addition, researchers noticed a correlation with T cell failure and a high viral load, opening up several directions researchers might pursue to improve response to therapeutic vaccines.
Future studies may combine therapeutic vaccines with other modalities that either lower viral load or enhance T cell function, particularly the proliferative capacity of T cells. Possible examples include anti-virals that could be given prior to therapeutic vaccination, or a cytokine that might boost the proliferation or survival of responding cells.
The researchers’ next plan is to compare the immune response using different therapeutic vaccine platforms. Although this work centered on chronic infection, research in this area should also inform the design of better therapeutic cancer vaccines, because many of the deficiencies in immune response are similar whether the antigen confronting the immune system is a virus or a tumor.