Question

Old people have weak immune system what could be the reason

Answer 1

Answer:

Some T cells kill antigens directly. Others help coordinate other parts of the immune system. Although the number of T cells does not decrease with aging, T-cell function decreases. This causes parts of the immune system to weaken and increases the risk for becoming ill.

Macrophages, which are white blood cells that ingest antigens, don't work as quickly as they used to. This slowdown may be one reason that cancer is more common among older people.

Answer 2

This causes parts of the immune system to weaken and increases the risk for becoming ill. Macrophages, which are white blood cells that ingest antigens, don't work as quickly as they used to. This slowdown may be one reason that cancer is more common among older people.