ABSTRACT
Infectious agents such as viruses, bacteria, fungi, protozoans, nematode worms, and prions cause diseases in humans and animals and claim lives. They are a concern for public health and cause loss to the economy of a country. Despite the function of the immune system to confer protection against diseases, pathogens have evolved strategies by which they bypass the immune system and cause life-threatening diseases. We discuss in this chapter (i) the different disease-causing infectious agents and how our immune system provides us immunity against these infectious agents; (ii) malfunctions of the immune system, strategies employed by the pathogen to bypass immune surveillance, and molecular mimicry used by pathogens to cause disease in the host; and (iii) computational immunology and its role in understanding the biology of infection.
