Chapter 33.7, Problem 3MI

Summary Introduction

When a person is exposed to an antigen, for example, an infection or vaccine, there is an initial lag phase up to several weeks, but before an antibody response is mounted. No antigen-specific antibody can be noticed in the blood during the latent period. But, when B cells have differentiated into plasma cells, Igs are secreted and it can be detected. During the primary antibody response, initially IgM appears and later IgG appears. During the secondary antibody response, the primary antibody response induces the immune system. Since, it possesses immunological memory by means of  memory B cells, each cell respond to various antigens.