: if our immune system become stronger every time we encounter a virus/bacteria/ect when we are young, why does it become weaker when we are old instead of continuing to improve?

Question

: if our immune system become stronger every time we encounter a virus/bacteria/ect when we are young, why does it become weaker when we are old instead of continuing to improve?

In: Biology

Answer 1

T cells and B cells are very important immune system components involved in fighting infections and forming lasting immunity. T cells are made in the thymus, which regresses with age and becomes a useless clump of fat cells by age 65. B cells develop in the bone marrow, which also loses function as you age.

So you lose the ability to make important immune system components with age.