How the Aging Immune System Makes Older Adults Vulnerable to COVID-19

Some researchers suggest the aging immune system plays a key role in older adults' elevated vulnerability to COVID-19, reports the New York Times . The "innate" immune system clears out damaged cells and other bodily debris in the absence of infection, but Buck Institute for Research on Aging CEO Eric Verdin says this ability starts lagging behind the amount of debris as one ages. The overwhelmed innate immune system is constantly on alert and inducing inflammation, while the thinking goes that aging cells are simultaneously releasing inflammatory substances of their own. This elevated state of chronic inflammation is associated with frailty, increasing the difficulty of fighting off pathogens. Verdin and other experts say the aging immune system also might be connected to cases of severe COVID-19 inducing a cytokine storm, which can cause organ failure. Over-inflammation also may partly explain why vaccines are not as effective for seniors. Typically following the innate immune system's response to infection is the more targeted response of the adaptive immune system, which can be compromised in older bodies by the inflammatory chaos. A reduction in T cells in older adults compounds the problem; researchers say exploration of COVID-19 treatments must account for these various factors.