One of the reasons the aging immune system fails in its job is the reduction of naive T cells, ready to tackle new threats. One approach to tackling this problem is to eliminate the cause - that too great a fraction of the immune system's limited resources is uselessly devoted to CMV-targeted memory cells. Another approach is outlined here: make more naive T cells available. "Throughout our lives, naive T-cells divide very slowly in our bodies. This helps maintain sufficient numbers of naive T-cells while we are young. As we age, naive T-cells are lost and the remaining ones speed up their division to make up for the losses in their numbers. Interestingly, after a certain point, this actually causes the numbers of naive T-cells to dwindle over time. Our data shows that once the number of naïve T-cells drops below a critical point, the rapidly dividing naive cells are very short lived. Based on this finding and other information, research suggests that some of the aging Americans may be better protected against disease by finding a way to jumpstart production of new naive T-cells instead of through revaccination. ... Even a slight boost in the number of these important T-cells could protect an aging person against disease for several years."