45.Types of the immune response. Primary and secondary immune response.
Explains adaptive immunity through its specificity and memory, then contrasts the primary response to a first antigen encounter with the faster, stronger secondary response on re-exposure. Covers humoral and cell-mediated immunity, the cell steps leading to plasma and memory cells, a primary versus secondary comparison table, and the basis of vaccination and direct antibody actions.
Topic 45 of 63 in the MU Pleven syllabus for Biology (Medicine, Year 1). The free AceMed note covers it in 10 sections, about 560 words (4 min of reading), with 41 flashcards.
In this note
Types of the immune response. Primary and secondary immune response.
Adaptive Immune Response
Primary Immune Response
Secondary Immune Response
Types of Adaptive Immune Responses
Primary Response: Formation of Antibodies by Plasma Cells
Secondary Response: Formation of Memory Cells
Immunological Basis of Vaccination
Mechanisms of Action of Antibodies
Direct Actions of Antibodies
Adaptive Immune Response
The adaptive immune response is characterized by specificity, memory, and a stronger response on repeated exposure to the same antigen. It is divided into primary and secondary immune responses.
Primary Immune Response
The primary immune response occurs when the immune system encounters an antigen for the first time.
During this phase, the immune system must:
Recognize the antigen
Activate specific lymphocyte clones
Produce antibodies
Establish immunological memory
This process takes time (approximately 1–2 weeks), which explains why symptoms of illness are often present during initial infection.
IgM is the hallmark antibody of a primary response.
As the response progresses, IgG production begins.
Antibody levels rise slowly and reach a relatively low peak.
Secondary Immune Response
The secondary immune response occurs upon subsequent exposure to the same antigen (2nd, 3rd, or later exposure).
Because immunological memory has already been established:
Antibody production begins immediately
The antigen is eliminated rapidly, often before symptoms appear
The response is stronger and longer lasting
IgG is the predominant antibody
IgA is involved in mucosal immunity
IgE predominates in allergic responses
Continue reading free
The whole note, all 10 sections, is free with an AceMed account, with its 41 flashcards. Premium adds flashcard recall, highlights and Ask AI.
