The immune system itself is a series of complex reactions to elements that cause various diseases. All foreign substances to the body are called antigens, and they can be of both external and internal origin (Perdue, 2020). Both proteins and more superficial bodies, for example, metals, can act as such substances. In response to an antigen’s appearance, the body begins to produce antibodies designed to neutralize pathogens. An antigen capable of causing a massive immune reaction to produce antibodies is called an immunogen.
An active immune response can be divided into two types: cell-mediated and humoral immunity. Both of these types interact with their goals in different ways, having other principles of operation. First, cell-mediated and humoral immunity is mediated by T-cells and B-cells, respectively (“Difference between immunity,” n.d.). Another critical difference is that the second type produces antibodies, so it is the primary protective mechanism. On the other hand, the cell-mediated type can remove tumor cells.
Existing stimuli can cause one of four hypersensitivity reactions, an extreme manifestation of the immune system. Immediate hypersensitivity refers mostly to allergic reactions, and tissue damage may be a side effect of this process (Mills, n.d.). The cytotoxic response is manifested in the direct interaction of an antibody with an antigen. The immune complex reaction is accompanied by the release of lysosomal enzymes, leading to tissue damage. Finally, the cell-mediated response is a delayed hypersensitivity reaction and can lead to complete tissue destruction.
Various vaccines are being developed to combat harmful microorganisms and help immunity, mainly divided into live-attenuated and inactivated inoculations. The first type uses weakened versions of disease-causing microbes to establish strong and long-lasting immunity (“Vaccine types,” 2020). However, people who are immunocompromised may have problems with these vaccines. In this case, it is possible to use an injection containing the destroyed version of the microbe. This vaccine is weaker and therefore requires more injections to build up immunity.
In extreme cases, a weakened immune system can manifest itself as immune disorders and may have serious complications, as, for example, in the case of AIDS. There are many different forms of these complexities, but they can be detected by a more prolonged and more severe disease course than people with normal immunity (Mayo Clinic, n.d.). Although these disorders are sometimes very slow, complications may be critical and include recurrent infections, internal damage, an increased risk of cancer, and death from a severe illness.
References
Difference between humoral and cell-mediated immunity. (n.d.). Byju’s. Web.
Mayo Clinic. (n.d.). Primary immunodeficiency.Mayo Clinic. Web.
Mills, M. P. (n.d.). Immunological and inflammatory aspects of periodontal disease. Dental Care Information for Professionals. Web.
Perdue, S. (2020). Immune system. In Encyclopædia Britannica. Web.
Vaccine types. (2020). Vaccines.gov. Web.