2009: "There is an accumulating body of evidence that a decline in immune function with age is common to most if not all vertebrates. For instance, age-associa

2009: "There is an accumulating body of evidence that a decline in immune function with age is common to most if not all vertebrates. For instance, age-associated thymic involution seems to occur in all species that possess a thymus, indicating that this process is evolutionary ancient and conserved. ... we show that life history trade-offs play a key role and we highlight the possible advantages of the age-related decline in thymic function." https://www.cell.com/trends/immunology/fulltext/S1471-4906(09)00105-7 https://www.cell.com/trends/immunology/fulltext/S1471-4906(0... 2021: "The thymus begins to degenerate as early as the second year of life and continues through aging in human beings, leading to a decreased output of naïve T cells, the limited TCR diversity and an expansion of monoclonal memory T cells in the periphery organs. These alternations will reduce the adaptive immune response to tumors and emerging infectious diseases, such as COVID-19, also it is easier to suffer from autoimmune diseases in older people. " https://clinicalepigeneticsjournal.biomedcentral.com/articles/10.1186/s13148-021-01197-0 https://clinicalepigeneticsjournal.biomedcentral.com/article...