Vaccines

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary goal of stimulating mucosal immunity in vaccination?

To provide systemic immunity against pathogens

To prevent infection at the point of entry of the infectious agent (correct)

To reduce the virulence of the pathogen

To develop memory immune responses against infectious agents

What type of vaccine is developed by culturing the virus on human cells and then successively on cells of a different species?

Inactivated vaccine

Conjugate vaccine

Subunit vaccine

Live attenuated vaccine (correct)

What is the characteristic that makes whole cell vaccines more potent?

Use of viral vectors

Ability to elicit cytotoxic T cells (correct)

Killing of microorganisms with chemicals

Ability to stimulate mucosal immunity

What is the purpose of attenuation in vaccine development?

To reduce the virulence of the pathogen Signup and view all the answers

What type of vaccine uses killed microorganisms that are treated with chemicals or heat?

Inactivated vaccine Signup and view all the answers

What is the advantage of live attenuated polio vaccines?

They stimulate mucosal immunity Signup and view all the answers

What type of vaccines are developed as a result of understanding that a single isolated constituent of a microorganism cannot activate an immune response?

Conjugate vaccines Signup and view all the answers

Which type of vaccine is synthesized in the lab using recombinant DNA technology?

Recombinant protein subunit vaccines Signup and view all the answers

What is the purpose of linking poorly immunogenic bacterial polysaccharides to proteins?

To enhance the immune response Signup and view all the answers

What type of vaccine is made from inactivated toxic compounds that cause illness?

Toxoid vaccines Signup and view all the answers

Which bacteria have conjugate vaccines developed against them?

Haemophilus spp. and Meningococcus Signup and view all the answers

What is a key advantage of subunit or recombinant vaccines compared to whole organism vaccines?

They are less reactogenic. Signup and view all the answers

Why may a single constituent vaccine not be fully effective?

It may not activate enough immune cells. Signup and view all the answers

What is a common way to enhance the immunogenicity of bacterial polysaccharides?

Conjugating them to a protein carrier. Signup and view all the answers

Why are adjuvants often added to conjugate vaccines?

To enhance the vaccine's immunogenicity. Signup and view all the answers

What type of vaccines may overcome the limitation of not triggering a cytotoxic T cell response?

Viral vectors and nucleic acid vaccines. Signup and view all the answers

What is the primary reason repeated doses of a vaccine may be required?

To boost immunity. Signup and view all the answers

What type of vaccine is made from inactivated toxic compounds that cause diseases such as tetanus and diphtheria?

Toxoid vaccine Signup and view all the answers

What is the purpose of using viral vectors in vaccine development?

To produce antigens inside host cells Signup and view all the answers

What type of vaccine is the Haemophilus influenza type B vaccine?

Conjugate vaccine Signup and view all the answers

What is the advantage of using mRNA vaccines?

They activate cytotoxic T cells Signup and view all the answers

What is the mechanism of action of self-amplifying RNAs in vaccines?

They encode the viral replication machinery Signup and view all the answers

What is the type of vaccine that was developed against Bordetella pertussis?

Killed whole bacterial cell vaccine Signup and view all the answers

What is a consequence of the segmented nature of the influenza virus genome?

Vastly increased diversity of circulating influenza viruses Signup and view all the answers

Why are new flu vaccines released every year?

To keep up with the rapid evolution of influenza viruses Signup and view all the answers

What is a goal of vaccination?

To induce the humoral adaptive immune responses Signup and view all the answers

What is a mechanism underlying the rapid evolution of influenza viruses?

Genome reassortment Signup and view all the answers

What is the result of the exchange of RNA segments between mammalian and avian influenza viruses?

Pandemic influenza Signup and view all the answers

What is the progressive increase in antibody affinity with repeated stimulation of B cells related to?

The recommended practice of giving multiple rounds of immunization Signup and view all the answers

Study Notes

Vaccination Goals and Immune Response

Vaccination aims to trigger humoral adaptive immune responses, leading to long-lived plasma and memory cells.
Multiple rounds of immunization are recommended to enhance antibody affinity and ensure protective immunity.

Annual Flu Vaccination

New flu vaccines are released yearly due to the rapid evolution of flu viruses.

Genome Reassortment

Genome reassortment between mammalian and avian influenza can result in pandemic strains, such as the 2009 H1N1.
The segmented genome of influenza allows genetic exchange, increasing diversity and contributing to quick viral evolution.

Importance of Mucosal Immunity

Effective vaccination should stimulate mucosal immunity, particularly for pathogens entering the body through mucosal surfaces.
Vaccines can be administered orally or by nasal inhalation to achieve this goal, exemplified by live attenuated polio vaccines.

Types of Vaccines

Live Attenuated Vaccines: Microorganisms treated to reduce virulence (e.g., BCG, polio).
Inactivated Vaccines: Pathogens killed through chemicals or heat (e.g., polio).
Subunit Vaccines: Composed of purified components or toxoids (e.g., tetanus, diphtheria).
Recombinant Protein Vaccines: Created using recombinant DNA technology (e.g., Hepatitis virus).
Conjugate Vaccines: Link bacterial polysaccharides to protein carriers to enhance immune response.

Vaccine Activation and Immunogenicity

Effective vaccines often require more than one component to activate various immune cell types.
Many vaccines need adjuvants to enhance immunogenicity.
Live attenuated vaccines can elicit a cytotoxic T cell response, unlike most other types.

Valence of Vaccines

Monovalent: Targets a single antigen or microorganism.
Multivalent: Designed to immunize against multiple strains or microorganisms (e.g., DTaP vaccine).

Revaccination Necessity

Repeated doses are sometimes necessary due to inadequate initial immune stimulation or waning immunity.

Vaccination Against Intracellular Microbes

Developing vaccines for intracellular microbes is challenging; however, several strategies are utilized:
- Viral Vectors: Incorporate microbial antigen genes into viruses, producing antigens within host cells.
- Bacterial Plasmids: DNA encoding antigens is ingested by antigen-presenting cells.
- mRNA Vaccines: Engineered to mirror naturally occurring mature mRNA, stimulating antigen production in host cells.

Safety and Efficacy of Vaccines

Killed whole bacterial cell vaccines (e.g., for whooping cough) can cause side effects, while live attenuated types may lead to complications in some cases.
Studies revealed that four components of Bordetella pertussis induce sufficient immune response through acellular vaccines.

Studying That Suits You

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