 This study found that both CMV and EBV can cause changes in the number of certain types of T cells in the bloodstream. These changes are most pronounced in older adults who have been exposed to both viruses. The study also showed that these changes may be amplified when people are infected with both viruses at the same time. This article was authored by Mali Zayhovsti, Alper Savergil, Marilena De Zebrower, and others.