Vaccination and Immune System Overview

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What role do activated helper T cells play in cell-mediated immunity?

They remove self-reactive T cells in the Thymus.

They directly kill infected cells.

They present antigens on MHCI receptors.

They release cytokines to activate cytotoxic T cells. (correct)

What stabilizes the recognition between cytotoxic T cells and the antigens displayed on infected cells?

CD4

CD8 (correct)

BCR

IgM

Where do lymphocytes and antigen-presenting cells (APCs) primarily interact?

Circulatory system

Bone marrow

Lymphoid tissues (correct)

Thymus

How are self-reactive T cells managed during their development?

They are removed in the Thymus. Signup and view all the answers

What happens to some cytotoxic T cells after they kill an infected cell?

They become memory T cells. Signup and view all the answers

What significant health issue did the last US case of Polio occur in 1986 relate to?

Global Polio eradication Signup and view all the answers

Vaccines primarily exploit which function of the adaptive immune system?

Memory function Signup and view all the answers

Which of the following is NOT a consideration in vaccine design?

Public health impact Signup and view all the answers

During a secondary immune response, how is the response characterized compared to the initial response?

Faster and stronger Signup and view all the answers

What does the term 'clonal propagation' refer to in the context of vaccine function?

Replication of memory B-cells Signup and view all the answers

What was the estimated number of measles, mumps, and rubella cases prevented by vaccination between 1994 and 2014?

332 million cases Signup and view all the answers

Which aspect of pathogen biology is crucial for selecting a good antigen for vaccine design?

Understanding of pathogen biology Signup and view all the answers

What kind of respiratory device did some Polio patients have to rely on due to the virus affecting their muscles?

Iron long Signup and view all the answers

What is the main characteristic of a toxoid vaccine?

It involves treated, inactive toxins. Signup and view all the answers

Which type of vaccine utilizes a benign microbe as a vector?

Recombinant vector vaccine Signup and view all the answers

Why do mRNA vaccines require careful delivery mechanisms?

mRNA may induce strong immune responses by itself. Signup and view all the answers

What is a potential reason for needing vaccine boosters?

The spike protein may undergo mutation. Signup and view all the answers

What form does an acellular or subunit vaccine take?

Purified macromolecules. Signup and view all the answers

What is a key feature of recombinant vector vaccines?

They utilize molecular cloning to produce antigens. Signup and view all the answers

Which step in vaccine development primarily assesses safety in a small population?

Phase I clinical trial Signup and view all the answers

Which description best fits whole-cell vaccines?

They contain live but weakened form of a virus. Signup and view all the answers

What is the primary function of B-cells in the humoral immune response?

Produce antibodies to neutralize toxins and pathogens Signup and view all the answers

What are cytotoxic T-cells primarily tasked with?

Killing infected cells Signup and view all the answers

Which component is essential for the activation of cytotoxic T-cells?

T-helper cells Signup and view all the answers

Which of the following best describes the memory function of the immune system?

Some B and T-cells become long-lived memory cells for quick reactivation Signup and view all the answers

What is the main reason for the success of smallpox eradication?

Limited host range for the virus and vaccination efforts Signup and view all the answers

Which type of immune response involves the activation of B-cells by T-helper cells?

Humoral response Signup and view all the answers

Which of the following statements about antibodies is true?

They can opsonize pathogens to promote phagocytosis Signup and view all the answers

What is a common feature of vaccines in terms of immune response?

They generate a rapid immune response without the disease Signup and view all the answers

Study Notes

Vaccination History and Development

Smallpox was a deadly disease that killed one in three infected individuals.
Vaccination efforts and global health initiatives led to its eradication, with the last natural case reported in 1977.
Polio was nearly eradicated globally, with the last U.S. case reported in 1986.
Measles, mumps, and rubella, saw a significant reduction in cases between the years 1994 and 2014; resulting in the saving of 732,000 lives.

Cell-Mediated Immunity

Any cell can display an antigen on the MHC receptor protein on its surface.
A cytotoxic T-cell with a TCR that recognizes the antigen (stabilized by CD8) becomes activated,
which in turn causes the cells to become memory T cells.
Cytotoxic T cells kill infected cells.

T-cell Receptor Function

T-cell receptors develop in the thymus.
Positive selection: T-cells that interact with MHC-peptide complexes in the thymus survive.
Negative selection: T-cells that interact too strongly with MHC-self peptides die.
In the thymus, self-reactive T cells are removed to prevent autoimmunity.

Lymphoid Tissues and Circulation

Lymphoid precursors differentiate into B or T cells in the bone marrow or thymus.
Immature lymphocytes travel to peripheral lymphoid organs, where they can interact with specific antigens.
This enables maturation, ensuring the lymphocytes are equipped to respond to pathogens.

Dendritic Cells and Activation

Immature dendritic cells reside in peripheral tissues.
Dendritic cells migrate through lymphatic vessels to regional lymph nodes.
Mature dendritic cells activate naive T cells in lymphoid organs like lymph nodes.

Transplant Suppressing Cytotoxic T cells

Cytotoxic T cells can attack the transplanted organ because they recognize it as non-self.
Medication that suppresses cytotoxic T cells is necessary to reduce potential organ rejection.

Humoral Response

The humoral response is mediated by B cells and antibodies.
Antibodies neutralize toxins and pathogens.
The system generates pathogen-reactive B and T cells through a random process.

Cell-Mediated Response

The cell-mediated response relies on T cells.
Cytotoxic T cells kill infected cells.
Helper T cells activate B cells.

Vaccine Design Considerations

A safe antigen is necessary for a vaccine.
How pathogens evolve plays a key role in vaccine efficacy.
Duration of the memory response is significant when developing a vaccine.
Understanding pathogen biology is crucial to design an effective vaccine.

mRNA Vaccines

mRNA vaccines rely on the production of viral proteins within the body's cells.
mRNA technology requires significant academic breakthroughs across several fields, including the understanding of RNA structure, function, decay, etc.

Vaccine Types

Whole-cell or whole-virus vaccines use inactivated or live-attenuated microbial agents.
Acellular or subunit vaccines use purified macromolecules or portions of the virus.
Toxoid vaccines use inactivated toxins.
Conjugated vaccines link a weak antigen to a strong antigen.
Recombinant vector vaccines use a benign microbe to provide a significant protein of the original microbe.

Vaccine Development Stages

Vaccine development requires multiple stages, including research and pre-clinical trials in animals, and clinical trials in humans.
Clinical trials progress through phases to evaluate safety and efficacy in different groups of participants.

Placebo-Controlled Trials

Placebos are used in clinical trials to establish a baseline for vaccine efficacy.
Researchers compare the rate of infection between vaccinated and placebo groups to determine the vaccine's effect.

Herd Immunity

Partial immunization of a population can protect the whole population, even those who cannot be vaccinated.
Contagious disease spreads through the population, but is reduced significantly if enough people are vaccinated and thus immune/protect others.

Summary of Vaccine Studies

Vaccines exploit the adaptive immune system's memory function.
Generally, antigens from a pathogen are used to prime the immune system.
Antigens can come from the whole pathogen cell, or from a pathogen fragment, such as the spike protein.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the history and development of vaccinations, including the eradication of smallpox and polio, as well as the impact of immunization on diseases like measles, mumps, and rubella. It also explores the mechanics of cell-mediated immunity and T-cell receptor function. Test your knowledge on these crucial topics in immunology.