2023-11-21 22:30:00
Allergic reactions, autoimmune diseases, chronic inflammations… If it happens that over the years, the immune system becomes disrupted, time tends to strengthen it. In fact, the acquired defense mechanisms are added to those which protect us from our birth.
What is the difference between innate immunity and adaptive immunity?
Let us remember, immunity (also called immune system) corresponds to all of the body’s defense mechanisms once morest foreign elements, in particular infectious agents such as virusTHE bacteriaTHE mushrooms or parasites.
Two types of immunity protect us from diseases: innate immunity et adaptive immunity.
The immune system: it’s first and foremost innate!
Innate immunity protects the individual from birth and provides an immediate reaction in the event of intrusion of microbes.
It first includes physical barriers in contact with the external environment such as the skin or mucous membranes. It also corresponds to all of the chemical barriers namely the different secretions such as mucus, saliva, gastric juice or tears.
Innate immunity also includes mechanisms triggered inside the body which prevent microbes from proliferating there. To his credit ? A certain type of cell (such as macrophagesneutrophils, etc.) and proteins (such as cytokinesinterferons…) notably at the origin of inflammatory symptoms.
Acquired and specific immunity
L’adaptive immunity acquired over the years through contact with microbes (bacteria, viruses, etc.). When these intruders enter the bloodstream, adaptive immunity usesantibody who are theirs specific. These antibodies are produced by white blood cells (or leucocytes).
Unlike innate immunity, adaptive immunity is not immediate. However, repeated encounters with pathogens make it more and more rapid and effective.
Adaptive immunity: how does it work?
Thanks to adaptive immunity, the body will, as it were, “record” infectious agents in memory cells. If these microbes were to enter the body once more, this memory would allow the activation of white blood cells (and more precisely B and T lymphocytes) within lymphoid tissues (located particularly in the rate, bone marrow and the lymph nodes).
- THE lymphocytes B directly secrete specific antibodies once morest the infectious antigen (this is called“humoral immunity”).
- On the other hand, the lymphocytes T destroy infected cells (we are talking regarding “cellular immunity). They also stimulate the production of antibodies by B lymphocytes a little more.
Note that when a virus, bacteria or any other infectious agent is contracted for the first time, you must wait approximately 2 to 3 weeks for these adaptive mechanisms to be triggered.
Vaccination: non-natural adaptive immunity
Vaccination artificially uses the mechanisms of adaptive immunity. Indeed, it consists of injecting an attenuated or inactivated infectious agent in order to produce an immune response which will be stored in memory. It thus offers protection once morest a particular microbe.
Adaptive immunity: active or… passive
When we talk regarding adaptive immunity, we most often refer to its active form. L’active adaptive immunity protects from a microbe by “memorizing” it in the body’s cells. It can be natural (following being infected) or artificial (through vaccination).
However, adaptive immunity can also be passive. This is the case when the body acquires specific antibodies without even having encountered the pathogen in question. THE transfer of maternal antibodies is the most natural example.
However, passive immunity can also be artificial. This is particularly the case of preventive treatments which consist of inject antibodies once morest a particular disease. For example, the drug Beyfortus®, the active ingredient of which, nirsevimab, is a long-acting monoclonal antibody, is capable of neutralizing RSV (the virus responsible for bronchiolitis). This preventive treatment is recommended for infants.
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