What are the types of immunity?

There are several ways to categorize and understand the types of immunity, which can be grouped into different categories based on their mechanisms and sources.

Active and Passive Immunity

Active Immunity

Active immunity is achieved when the body's own immune system produces antibodies in response to a pathogen. This can occur through:

• Natural Immunity: Exposure to the actual disease, which triggers the immune system to produce antibodies23.
• Vaccine-Induced Immunity: Introduction of a killed or weakened form of the disease organism through vaccination, which also triggers the immune system to produce antibodies23.

Passive Immunity

Passive immunity is provided when a person is given antibodies to a disease rather than producing them through their own immune system. This can occur through:

• Natural Passive Immunity: For example, a newborn baby acquiring antibodies from the mother through the placenta23.
• Artificial Passive Immunity: Through the administration of antibody-containing blood products such as immune globulin23.

Innate and Adaptive Immunity

Innate Immunity

Innate immunity is a general, non-specific defense mechanism present from birth. It includes barriers such as the skin and mucous membranes, as well as cells like phagocytes (neutrophils, macrophages), mast cells, eosinophils, and basophils. This system acts quickly but does not provide long-term immunity345.

Adaptive Immunity

Adaptive immunity is a specialized defense mechanism that develops over time. It is specific to the pathogen and involves the action of lymphocytes (B cells and T cells). This system remembers past infections and can mount a quicker and more effective response upon subsequent exposures345.

Community Immunity

Community Immunity (Herd Immunity)

Community immunity occurs when a sufficient percentage of a population is immune to a disease, thereby protecting those who are not immune, such as the very young or individuals with weakened immune systems. This type of immunity is indirect and does not involve physical components of the immune system but rather the collective protection provided by the immune individuals in the community1.

Cocooning

Cocooning is a form of community immunity focused on protecting a specific individual, such as ensuring that everyone around a young infant or a person with weakened immunity is immune to certain diseases1.

In summary, the main types of immunity are:

• Active Immunity: The body produces its own antibodies.
• Passive Immunity: Antibodies are provided from an external source.
• Innate Immunity: General, non-specific defense mechanisms present from birth.
• Adaptive Immunity: Specialized, specific defense mechanisms that develop over time.
• Community Immunity: Collective protection provided by immune individuals in a community.