What is Active and Passive Immunity?

Immunity is the body’s ability to destroy foreign substances and pathogens to prevent further infection. The first line of defense against pathogens in a human body is through barriers such as the skin, mucus layers, and saliva. This is known as innate immunity. The second line of defense is through phagocytes; this is again produced by innate immunity. The third line of defense is adaptive immunity.

Active immunity and passive immunity are two types of adaptive immunity. A distinct difference between active and passive immunity is that active immunity develops due to the production of antibodies in the person’s own body, while passive immunity is developed by antibodies produced outside and then introduced into the body.

Nonspecific Defenses

Immunity is the name given to the body’s defense system to protect against pathogens and fight infections. This is a complex system, so immunity is divided into categories. One way of classifying immunity is nonspecific and specific.

These defenses work against all pathogens and foreign substances. Examples include physical barriers such as mucous membranes, nose hair, eyelashes, and eyelashes. Chemical barriers are also a non-specific type of defense. Chemical barriers include the low pH of gastric juice, the skin, the alkaline environment of the vagina, the lysozyme enzyme in the tears and earwax.

Specific Defenses

This line of defense is active against certain threats such as certain bacteria, viruses, fungi, prions, and mold. A particular defense against one pathogen is usually not effective against a different pathogen. An example of specific immunity is chickenpox resistance from exposure or a vaccine. Another way to group immune responses is as follows:

Innate Immunity

It is a type of innate immunity based on hereditary or genetic predisposition. This type of immunity provides protection from birth to death. Innate immunity consists of external defenses (first line of defense) and internal defenses (second line of defense). Internal defenses include fever, complement system, natural killer (NK) cells, inflammation, phagocytes, and interferon. It is also known as innate immunity, genetic immunity or familial immunity.

Adaptive immunity, or acquired immunity, is the third line of defense in the body. This is protection against certain types of pathogens. Acquired immunity can be natural or artificial in nature. Both natural and artificial immunity consist of passive and active ingredients. Active immunity is caused by an infection or vaccination, while passive immunity is caused by acquiring antibodies naturally or artificially. The differences between active and passive immunity are as follows:

Active Immunity

Its active immunity comes from exposure to a pathogen. Surface markers on the pathogen’s surface act as antigens, which are binding sites for antibodies. Antibodies are Y-shaped protein molecules that can exist on their own or bind to the membrane of specialized cells. The body does not keep a reservoir of antibodies on hand to immediately eliminate an infection. A process called clonal selection and extension creates sufficient antibodies.

Active Immunity Examples

An example of natural activity immunity is fighting the common cold. An example of artificial active immunity is resistance to a disease due to immunization. This is an overreaction against an antigen arising from the active immune system.

Features of Active Immunity

• Active immunity occurs when you are exposed to a pathogen or an antigen of a pathogen.

• Exposure to antigen leads to antibody production. These antibodies essentially mark a cell to be destroyed by special blood cells called lymphocytes.

• Cells involved in active immunity are T cells (cytotoxic T cells, helper T cells, memory T cells and suppressor T cells), B cells (memory B cells and plasma cells) and antigen-presented cells (macrophages, dendritic cells and B cells, ).

• There is a delay between antigen exposure and immunization. Initial exposure causes what is called the primary reaction. If the person is re-exposed to the pathogen at a later time, the reaction is much faster and stronger. This is called a secondary response.

• Active immunity lasts long, may span years or a whole life.

• Active immunity has few side effects. It may play a role in autoimmune diseases and allergies, but it usually doesn’t cause problems.

Passive Immunity

Passive immunity does not require the body to make antibodies against antigens. Antibodies are given outside the organism.

Passive Immunity Examples

An example of natural passive immunity is protecting an infant against certain infections by getting antibodies through colostrum or breast milk. An example of artificial passive immunity is an injection of antiserum, which is a suspension of antibody particles. Another example is an injection of snake antidote after a bite.

Characteristics of Passive Immunity

• Passive immunity is given externally, so it does not require exposure to an infectious substance or antigen.

• There is no delay in passive immune action. His reaction to an infectious agent is immediate.

• Passive immunity is not as long lasting as active immunity. Usually it is only effective for a few days.

• A condition called serum sickness can be caused by exposure to antisera.

In summary The two main types of immunity are active and passive immunity. Active immunity is an immune response to a pathogen. It is based on the body’s production of antibodies that take time to initiate an attack against bacteria or viruses. Passive immunity occurs when antibodies are given instead of being produced (for example, from breast milk or antiserum). Immune response occurs immediately. Other types of immunity include innate and acquired immunity as well as specific and nonspecific defenses.