ABSTRACT
In this chapter, we look at the adaptive immune response. In Chapter 15, we learned that a host has a formidable array of innate defense mechanisms that in many cases are more than enough to handle potential infections. In addition to innate defenses, the host has the ability to mount a defense that is specific to a particular pathogen. This defense is called the adaptive immune response. The adaptive response has the benefit of immunological memory: when a host is infected by a pathogen, the adaptive immune response not only clears the infection from the body but also remembers the pathogen. When that pathogen invades the host again, even decades after the first infection, the pathogen will be defeated even more quickly. Immunological memory is also the reason that vaccinations work. As we look at the adaptive response, you will see that it is like a carefully choreographed ballet in which the dancers all depend on one another in giving a powerful performance.
