microscope view of T cellFor the Allen Institute, Jake Siegel writes about how populations of T cells change over the lifespan, shedding new light on why we all become more vulnerable to infection as we age. Using a new method developed at the institute, the researchers discovered a new subtype of T cell that disappears after childhood and learned that a type of T cell once believed to be resistant to age-related changes is, in fact, not. The researchers hope that the technology can unlock more insights about other components of the immune system and advance vaccine design. Image: National Institute of Allergy and Infectious Diseases