How Much Do You Know about Innate and Adaptive Immunity? The main function of the immune system is to defend the host against pathogens and toxins. The cells of the immune system remain as individual cells instead of forming organs. These immune cells are distributed throughout the body. However, these cells of the immune system work in a cooperative manner to accomplish their tasks to the human body. The unique feature of the immune system is that it can recognize its own molecules from foreign molecules. Generally, the immune response involves many key stages: pathogen recognition, activation and initiation, regulation, and the production of immune memory. The vertebrate immune system consists of two basic branches: Innate and adaptive immunity. Although these immunities have different effects, they usually work together to fight infections. What is innate immunity? The innate immune system, also called the non-specific immune system, is part of the immune system and provides the first line of defense against infection. The molecules and receptors of the immune system provide extensive protection. In fact, it is the natural immunity of all animals and plants. It produces a variety of molecules and can identify almost any invading pathogen. Basically, the first response is slow and highly specific to invading pathogens. However, the response to the second attack was more rapid, which is the basis of the vaccine. The innate immune system includes different cells, such as eosinophils, monocytes, macrophages, natural killer cells, tor-like receptors (TLR), and a series of soluble mediators, such as the complement system. What is adaptive immunity? The adaptive or specific immune system mainly attacks specific invaders. It is composed of highly specialized cells, which are called thymus-derived T lymphocytes and bone marrowderived B lymphocytes. These cells can recognize different foreign antigens in a very precise way, and have the ability to generate immune memory, so that they can recognize previously encountered pathogens. There are two types of adaptive immunity: humoral immunity and cellular immunity. Antibody molecules secreted by B lymphocytes can neutralize extracellular pathogens and mediate humoral immunity, while T lymphocytes can clear infected cells and help other immune responses, thereby mediating cellular immunity. What are the similarities between innate and adaptive immunity? Innate immunity and adaptive immunity are two types of immune systems that exist in our body. Both types of immune systems can fight pathogens and protect our bodies. What is the difference between innate and adaptive immunity? The main difference between innate immunity and adaptive immunity is that innate immunity is a rapid immune response that provides the first line of immune defense against infection, while