immunités

Immunities refer to the state of being exempt from or protected against a particular obligation, law, or, more commonly, a disease. In a legal context, diplomatic immunity, for instance, protects foreign officials from prosecution in the host country. In the realm of biology and medicine, immunity is the body's natural defense system against pathogens, such as bacteria, viruses, and other foreign substances. This biological immunity can be acquired naturally through infection and recovery, or artificially through vaccination.

The immune system is a complex network of cells, tissues, and organs that work together to identify and destroy invaders. Key components include white blood cells like lymphocytes (B cells and T cells) and phagocytes, which engulf and destroy pathogens. Antibodies, produced by B cells, can neutralize or mark pathogens for destruction. There are two main types of immunity: innate and adaptive. Innate immunity is the body's first line of defense, providing a general, non-specific response to threats. Adaptive immunity is more specific, developing over time and creating immunological memory, which allows for a faster and stronger response upon subsequent exposure to the same pathogen. Herd immunity occurs when a sufficient percentage of a population is immune to a disease, making its spread unlikely, thereby protecting those who are not immune.