Question

Why does immune system become weak in old human beings?

Answer 1

Dear student,
Immune system becomes weak in old aged individual because the process of ageing reduces the efficiency of immune system which leads to less production of antibodies with respect to antigens. Immune system can not distinguish between self and non self cells leading to auto immune disorders. T cells and macrophages responds less quickly to antigens. Memory cell also becomes weak and could not remember previous attack by the same antigens.

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