immunites

Immunities refer to the ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitised white blood cells. This resistance is often acquired through prior exposure to the infectious agent, a process known as natural immunity, or through vaccination, which is artificial immunity.

There are two main types of immunity: innate and adaptive. Innate immunity is the non-specific defence system present from birth. It includes physical barriers like skin and mucous membranes, as well as cellular and molecular defences that act quickly but are not tailored to specific pathogens. Adaptive immunity, on the other hand, is acquired over time and is highly specific. It involves the recognition of particular antigens and the development of a targeted response, including the production of antibodies and memory cells, which allows for a faster and stronger response upon subsequent encounters with the same pathogen.

Passive immunity is another form, where pre-formed antibodies are transferred from one individual to another, such as from mother to child across the placenta or through breastfeeding. This provides immediate protection but is temporary as the individual's own immune system does not produce the antibodies. Understanding immunities is crucial in medicine for developing vaccines, treating diseases, and managing infectious outbreaks.