The document discusses the immune response process. During a primary response to an antigen, there is a latent period followed by an exponential increase in IgM antibodies and then a declining phase with IgG antibodies produced. Some B cells become memory cells. Upon a secondary exposure, the immune response is faster, stronger, and involves memory cells, resulting in less severe symptoms or no symptoms from the real disease. Vaccines cause a primary response to mimic a secondary response from the real disease.
