Origin and differentiation of human memory CD8 T cells after vaccination.The differentiation of human memory CD8 T cells is not well understood.  This longitudinal analysis showed that the memory pool originates from CD8 T cells that divided extensively during the first two weeks after infection and is maintained by quiescent cells that divide less than once every year (doubling time of over 450 days). 
Origin
Origin and differentiation of human memory CD8 T cells after vaccination.The differentiation of human memory CD8 T cells is not well understood. 
differentiation
Origin and differentiation of human memory CD8 T cells after vaccination.The differentiation of human memory CD8 T cells is not well understood. 
human memory CD8 T cells
Origin and differentiation of human memory CD8 T cells after vaccination.The differentiation of human memory CD8 T cells is not well understood.  This open chromatin profile at effector genes was maintained in memory CD8 T cells isolated even a decade after vaccination, indicating that these cells retain an epigenetic fingerprint of their effector history and remain poised to respond rapidly upon re-exposure to the pathogen.
vaccination
Here we address this issue using the live yellow fever virus (YFV) vaccine, which induces long-term immunity in humans. 
live yellow fever virus (YFV) vaccine
We used in vivo deuterium labelling to mark CD8 T cells that proliferated in response to the virus and then assessed cellular turnover and longevity by quantifying deuterium dilution kinetics in YFV-specific CD8 T cells using mass spectrometry. 
mass spectrometry