Innate immunity is protection that you’re born with. Your innate immune system is part of your body’s first-line defense. It responds to invaders right away by attacking any organism that shouldn’t be in your body. It doesn’t need prior training to tell the difference between cells that belong in your body and those that don’t.i
The white blood cells involved in innate immunity don’t learn to recognize certain invaders. They also have no memory of attacking invaders and don’t offer protection against specific germs (or the infections they cause) in the future.
That’s where acquired immunity comes into play. Acquired immunity, also called adaptive or specific immunity, is protection your body gains (acquires) over time from exposure to germs. Certain white blood cells called lymphocytes remember specific invaders and can tell when they don’t belong in your body. So, if those invaders try to get in again, the lymphocytes can quickly spring into action and work with other cells to eliminate the threat.
Vaccines support your acquired immunity by training its cells to identify and destroy invaders before they make you sick.
Conditions and Disorders
What disorders and diseases can affect the immune system?
Conditions that can interfere with the normal workings of your immune system include:
- Allergies. An allergy is your body’s reaction to a substance that’s normally harmless. Your immune system overreacts to the presence of that substance, leading to a range of symptoms from mild to severe.
- Autoimmune diseases. These conditions occur when your immune system attacks its own healthy cells by mistake. Lupus and rheumatoid arthritis are examples of common autoimmune diseases.
- Primary immunodeficiency diseases. These inherited conditions prevent your immune system from working properly. They make you more vulnerable to infections and certain diseases.
- Infectious diseases. Infectious diseases happen when germs enter your body, replicate and cause damage. HIV and mononucleosis (mono) are examples of infectious diseases that weaken your immune system and can lead to serious illness.