Difference Between Innate and Adaptive Immunity

What is Immunity?

The defence system of the body against infections and diseases is known as immunity. Immunity is machinery that helps the body fend off harmful pathogens that enter the body. We come in contact with millions of pathogens which can cause diseases or infections every day. However, we seldom catch an infection or get ill. All thanks to our immunity! The immune system fights the pathogens with antibodies and protects us from catching a disease. It is an always active mechanism that runs continuously in the body to keep us fit and healthy.


Innate Vs Adaptive Immunity

Our immune system is made up of organs, cells, tissues and some proteins. It not only combats the pathogens entering the body but also gets rid of the dead and malfunctioning cells. The kind of immunity that is present by birth in all individuals is innate immunity. It is the body’s natural defence system present right from birth and protects us against the harmful antigens. On the other hand, as we grow up, our body acquires the second kind of immunity that is known as adaptive immunity. Unlike innate immunity, adaptive immunity is not present by birth but is acquired by the body. Hence, it is also known as acquired immunity.

Let us see the major differences between innate and acquired or adaptive immunity in this article.


Differences Between Innate and Adaptive Immunity

Properties

Innate Immunity

Adaptive Immunity

Meaning

It is a non-specific immunity present by birth in every individual.

It is specific and acquired as one grows up.

Definition

The kind of immunity which is not antigen-specific and works as soon as an antigen enters the body.

It is the type of immunity which involves antigen-specific immune response and is acquired after the body comes in contact with the antigen for the first time.

Line of Defense

Innate immunity is the first line of defence against the antigens entering the body.

Adaptive immunity is the second line of defence as it acts when pathogen cross the barrier of innate immunity.

Presence in the body

It is present by birth.

It is not present by birth but is acquired as one grows up and comes in contact with various antigens.

Inducibility

Innate immunity is not inducible. That is, it is not formed in response to the presence of its substrate.

Adaptive immunity is inducible.

Specificity

It is non-specific.

It is specific.

Presence in the Body

It is always present in the body.

It develops only upon exposure to antigens.

Examples of Cells Involved

Mast cells, dendritic cells, Phagocytic leukocytes, Natural killer cells, etc.

Killer CD8+ T-cells, Helper CD4+ T-cells, B-cells, etc.

Molecules involved

Interferons, Acute-phase proteins, Cytokines, Complements

Cytokines, Antibodies.

Components

Skin, mucous, mucous membranes, epithelial cells, phagocytes etc.

Lymphoid organs that produce specialized cells called T cells and B cells.

Fights against

All sorts of pathogens or antigens entering the body.

Has the ability to fight against a specific infection.

Immunological Memory

Innate immunity does not keep a memory of the pathogens.

Adaptive immunity has memory cells to keep the memory of the pathogens.

Potency

It has low potency or is less effective as compared to adaptive immunity.

Adaptive immunity is more effective.

Response Time

Response time is short and the action is immediate usually.

Response time is slower than innate immunity.

Inheritance

It is inherited from parents.

It is not inherited from parents.

FAQs (Frequently Asked Questions)

Q1. What are the Anatomical and Physiological Barriers in Case of Innate and Adaptive Immunity?

Ans: In case of innate immunity, the anatomical and physiological barriers are skin, mucous membranes, temperature, pH, chemicals, etc. and in case of adaptive immunity, it is lymph nodes, spleen, mucosal-associated lymphoid tissue, etc.

Q2. What is the Basic Difference Between Innate and Adaptive Immunity?

Ans: The kind of immunity that is present by birth in all individuals is innate immunity. It is the body’s natural defence system present right from birth and prevents us against the harmful antigens. On the other hand, as we grow up, our body acquires the second kind of immunity that is known as adaptive immunity. Unlike innate immunity, adaptive immunity is not present by birth but is acquired by the body. Hence, it is also known as acquired immunity.

Q3. What Kind of Immunity is Only Exclusive to Vertebrates?

Ans: Innate immunity that is present by birth is found in all organisms- vertebrates and invertebrates. But adaptive immunity is found only in jawed organisms or the vertebrates.

Q4. What are the Factors that Cause Immune Evasion in the case of Innate Immunity? How is it Different from Adaptive Immunity?

Ans: Innate immunity mostly occurs as a result of pathogenic virulence factor because it is non-specific and neither does it consist of memory cells to keep the memory of the infection. However, in case of adaptive immunity, it is triggered by the mutation of the recognized antigen since it is specific and also keep the memory of the infection and the antigens.