Microbiology is the study of microscopic organisms, whether single-celled and multi-celled. Many microbes are responsible for the spread of infectious diseases. The study of the immune system in a variety of organisms is known as immunology. Microbes that cause disease induce an immunological response and control the immune system during infection, hence microbiology and immunology go hand in hand. Through inhalation, ingestion, and touch, we are constantly exposed to a variety of pathogens. The majority of these pathogens, such as flatworms, bacteria, fungi, and viruses, are protected by the immune system. Recent discoveries have highlighted the value of employing microbes to study the immune system, as well as the importance of microorganisms in the immune system's growth and function.
Molecular immunology is a field of immunology that investigates the immune system and its functions at a molecular level. Molecular immunologists are interested in processes like immune cell signalling and activation, as well as the structure and function of molecules like receptors and mediators, among others. It has become feasible to not only determine how the immune system operates at the molecular level, but also to manipulate various components of the system for immunotherapy purposes, thanks to this field of study. Because proteins are the most common antigens of biological relevance, elucidating the antigenic structure of proteins has been a primary focus of molecular immunology.