The flu (influenza) is a seasonal virus that causes mild to severe symptoms. Some people recover in about a week, while others can be at risk of serious, life-threatening complications. There are many strains of the virus.
The risk of complications increases if you’re over the age of 65. Older adults tend to have a weaker immune system, naturally occurs as we age. And when your immune system isn’t robust, it becomes harder for the body to fight off a virus.
These white blood cells are an important part of the immune system. They help your body fight antigens which are bacteria, viruses, and other toxins that make you sick. If your doctor says you have a weakened immune system, that means there aren’t enough white blood cells in your bloodstream.
Lymphocytes and how they work
Cells are produced constantly by the bone marrow and these cells l become lymphocytes.
Some of these lymphocytes will enter your bloodstream, but most will move through your lymphatic system.