Abstract
In this chapter, we will focus on virus infections and understand how our immune system is combating them. First, we will discuss the principles of the effector functions of innate and adaptive immunity against acute virus infections. Then we will shift to chronic virus infections and realize that each of us carries an individual virome. The latter is formed by dozens of different virus types, many of which are not harming us when we are healthy but may get a problem in an immunocompromised status the context of common diseases. Furthermore, we will learn how microbes can be transferred from different animals to humans and will use influenza virus and SARS-CoV-2 as master examples. Finally, we will elaborate the impact of vaccination against influenza and COVID-19.