Immunity is the ability of an organism to resist infections and diseases by recognizing and eliminating pathogenic (disease-causing) agents.
Innate immunity is the body’s first line of defense against pathogens. It is general and non-specific, which means it does not differentiate between types of pathogens. Adaptive immunity is a type of immunity that is built up as we are exposed to diseases or get vaccinated. It is also called acquired immunity for that reason.
It is important to understand the difference between innate and adaptive immunity because these two immune responses have different characteristics and play different roles in protecting the body against infections and diseases.
Definition of innate immunity
Innate immunity is the first line of defense against infections and diseases. It is non-specific, meaning that it does not require prior exposure to the pathogen in order to mount a response.
Innate immunity includes physical and chemical barriers, such as skin and mucous membranes, as well as various immune cells and molecules that help to recognize and eliminate pathogens.
Examples of innate immune responses include the production of antimicrobial substances, such as lysozyme (an enzyme that breaks down the cell walls of bacteria) and interferons (proteins that inhibit viral replication), as well as the activation of immune cells, such as macrophages (which phagocytose or engulf and destroy, pathogens) and neutrophils (which produce toxic substances to kill pathogens).
Definition of adaptive immunity
Adaptive immunity is the second line of defense against infections and diseases, and it is specific, meaning that it requires prior exposure to the pathogen in order to mount a response. After encountering a pathogen for the first time, the adaptive immune system produces specialized immune cells called antibodies and T cells that can recognize and eliminate the pathogen.
Adaptive immunity is specific, meaning that it requires prior exposure to the pathogen in order to mount a response. After encountering a pathogen for the first time, the adaptive immune system produces specialized immune cells called antibodies and T cells that can recognize and eliminate the pathogen.
Adaptive immunity also involves the production of memory cells, which remain in the body after an infection has been cleared. These memory cells allow the body to mount a faster and more effective response to the same pathogen if it is encountered again in the future.
Examples of adaptive immune responses include the production of antibodies by B cells, which can neutralize pathogens or mark them for destruction by other immune cells, and the activation of T cells, which can kill infected cells or stimulate other immune cells to attack pathogens.
Differences between innate and adaptive immunity
There are differences between innate and adaptive immunity in terms of their physical and functional characteristics, as well as their role in protecting against infections and diseases.
Physical and functional differences between innate and adaptive immunity:
Innate immunity is non-specific and involves physical and chemical barriers, such as skin and mucous membranes, as well as various immune cells and molecules, such as macrophages, neutrophils, and antimicrobial substances.
Adaptive immunity is specific and involves antibodies and T cells, which are produced after initial exposure to a pathogen. Adaptive immunity also involves the production of memory cells, which remain in the body after an infection has been cleared and allow for a faster and more effective response to the same pathogen if it is encountered again in the future.
Innate immunity responds quickly to infections, but its response is not as targeted or long-lasting as the response of adaptive immunity. Adaptive immunity requires more time to mount a response, but its response is more targeted and long-lasting.
The role of innate and adaptive immunity in protecting against infections and diseases:
Innate immunity provides the first line of defense against infections and diseases, while adaptive immunity provides a more targeted and long-lasting response.
Together, these two immune responses work together to protect the body against a wide range of pathogens. Innate immunity recognizes and eliminates a variety of pathogens, while adaptive immunity produces specialized immune cells that can recognize and eliminate specific pathogens.
The combination of innate and adaptive immunity allows the body to mount an effective immune response to a wide range of pathogens, including viruses, bacteria, fungi, and parasites.
Comparison Table Innate Immunity Vs Adaptive Immunity
| Innate Immunity | Adaptive immunity |
| Innate immunity is something already present in the body. | Adaptive immunity is created in response to exposure to a foreign substance. |
| Non-Specific | Specific |
| Fights any foreign invader | Fight only specific infection |
| Rapid Response | Slow (1-2 weeks) Response |
| Limited and Lower potency | High potency |
| Once activated against a specific type of antigen, the immunity remains throughout the life. | The span of developed immunity can be lifelong or short. |
| Innate type of immunity is generally inherited from parents and passed to offspring. | Adaptive immunity is not passed from the parents to offspring, hence it cannot be inherited. |
| Cannot react with equal potency upon repeated exposure to the same pathogen. | Adaptive system can remember the specific pathogens which have encountered before. |
| Present at birth | Develops during a person’s lifetime and can be short-lived. |
| None Allergic Reaction | Immediate and Delay hypersensitivity |
| Used Against microbes | Used Against Microbes and non-microbial substances called antigens |
| No memory | Long term memory |
| Limited Diversity | High Diversity |
| Faster response | Slower response |
| Alternative and lectin pathways | Classical pathway |
| Skin, Mucous membranes, Temp, pH, chemicals, etc. | Lymph nodes, spleen, mucosal associated lymphoid tissue. |
| The innate immune system is composed of physical and chemical barriers, phagocytic leukocytes, dendritic cells, natural killer cells, and plasma proteins. | Adaptive immune system is composed of B cells and T cells. |
| Evolutionary, older and is found in both vertebrates and invertebrates. | Adaptive immunity system has been developed recently and is found only in the vertebrates. |
| White blood cells fight bacteria, causing redness and swelling when you have a cut. | Chickenpox vaccination so that we don’t get chickenpox because the adaptive immune system has remembered the foreign body. |
Conclusion
Innate immunity is non-specific and involves physical and chemical barriers and various immune cells and molecules, while adaptive immunity is specific and involves antibodies and T cells. Innate immunity responds quickly to infections, but its response is not as targeted or long-lasting as the response of adaptive immunity.
Understanding the differences between innate and adaptive immunity is important for understanding how the immune system works to protect the body against infections and diseases.
