Vaccine Flashcards
Slides
What are vaccine?
A vaccine[Latin vacca, cow] is a preparation of one or more microbial antigens used to induce protective immunity.
It may consist of killed microorganisms, living, weakened microorganisms(attenuated vaccine); inactivated bacterial toxins(toxoids); purified cellular subunits; recombinant vectors; or DNA.
What is the goal of vaccination?
Vaccination attempts to induce antibodies and activated T-cells response to protect a host from future infection.
What are the types of vaccines
Types of Vaccines
Killed Microorganisms: These vaccines contain microbes that have been killed. They can’t cause disease, but they can still stimulate your immune system to protect you.
Living, Weakened Microorganisms (Attenuated Vaccines): These vaccines use live microbes that have been weakened so they can’t cause serious illness in people with healthy immune systems. They provide strong and long-lasting immunity.
Inactivated Bacterial Toxins (Toxoids): Some bacteria produce harmful toxins. Toxoid vaccines contain these toxins, but they have been inactivated so they can’t harm you. They teach your immune system to fight the toxin, not the bacteria itself.
Purified Cellular Subunits: These vaccines contain only parts of the microbe, like proteins or sugars. They don’t use the whole microbe, just enough to train your immune system.
Recombinant Vectors: These vaccines use harmless viruses or bacteria to deliver microbial DNA into your body. Your cells then make antigens based on this DNA, which trains your immune system.
DNA Vaccines: These contain only the genetic material (DNA) that codes for the antigens. Your cells use this DNA to produce the antigens, which then stimulate an immune response.
Vaccination is the process of giving a vaccine. The goal is to induce the production of antibodies (proteins that fight microbes) and activate T-cells (a type of immune cell) so that if you encounter the microbe in the future, your immune system can respond quickly and protect you from illness.
What marks the beginning of the modern era of vaccine? & year
Edward Jenner (1798):
Cowpox and Smallpox: Edward Jenner discovered that people who were exposed to cowpox, a disease affecting cows, did not get smallpox, a serious disease affecting humans. He used material from cowpox lesions to create the first smallpox vaccine.
Who discovered Anthrax Vaccine & when?
Overview
Louis Pasteur (1881):
Anthrax Vaccine: Louis Pasteur developed a vaccine for anthrax, a deadly disease affecting both animals and humans. This was another significant milestone in vaccine development.
What are adjuvants and what do they do?
The word “adjuvant” comes from the Latin word meaning “aiding” because they help boost the immune system’s response to the vaccine.
Adjuvants help vaccines work better by:
Enhancing the Immune Response: They increase the strength and duration of the immune response.
Prolonging Antigen Interaction: They keep the antigens around longer so the immune system has more time to recognize and respond to them
What ate the Examples of Adjuvants and how do they function
Oil in Water Emulsions (Freund’s Incomplete Adjuvant):
This mixture creates a depot effect, where the antigen is released slowly over time, giving the immune system a prolonged period to respond.
Aluminium Hydroxide Salts (Alum):
Alum is one of the most common adjuvants. It helps to attract immune cells to the site of injection and enhances the uptake of the antigen by these cells.
Beeswax:
Beeswax can be used in formulations to provide a slow-release effect similar to oil in water emulsions.
Bacteria (Live or Killed):
Certain bacteria or their parts can act as adjuvants by stimulating the immune system directly, enhancing the response to the vaccine’s antigens.
What diseases have partially developed vaccines
Influensa
Tuberculosis
What are the Types of Immunity & how they work
Active Immunity
What it is: Active immunity happens when your body is exposed to a disease-causing microbe (or part of it) and makes its own antibodies and memory cells to fight it.
How it works: Vaccines introduce a safe form of the microbe (like a killed or weakened version) or parts of it (like proteins) into your body. Your immune system responds by creating antibodies and memory cells that will remember the microbe and fight it if you encounter it in the future.
Passive Immunity
What it is: Passive immunity involves giving pre-made antibodies to someone so they can fight off a disease immediately.
How it works: This is done by administering immunoglobulins (antibodies). These antibodies provide immediate protection but don’t last long because your body didn’t make them. They are often used for immediate protection against diseases like tetanus, botulism, and diphtheria.
Passive-Active Immunity
I
What it is: This approach combines both passive and active immunity methods.
How it works: First, pre-made antibodies (immunoglobulins) are given for immediate protection. At the same time, a vaccine is administered to stimulate the body’s own immune system to develop long-term protection.
Example of active-passive immunity?
Examples:
Rabies: When someone is potentially exposed to rabies, they receive both Rabies Immune Globulin (RIG) for immediate protection and the rabies vaccine for long-term protection.
Tetanus: If someone has a severe wound and isn’t up to date on their tetanus shots, they may receive both Tetanus Antitoxin (ATS) for immediate protection and Tetanus Toxoid (TT) vaccine for long-term protection.
Examples of antibodies used in passive immunity with vaccines
Hepatitis B Immune Globulin: Used to provide immediate protection against Hepatitis B.
Cytomegalovirus (CMV) Immune Globulin: Used to protect against CMV, especially in transplant patients.
Rabies Immune Globulin (RIG): Used immediately after a potential rabies exposure.
Tetanus Antitoxin: Provides immediate protection against tetanus.
Vaccinia Immune Globulin: Used to protect against complications from the smallpox vaccine.
Varicella Zoster Immune Globulin: Used to protect against chickenpox in high-risk individuals.
What’s Equine Antitoxins and it’s types
Equine Antitoxins
These are antibodies derived from horses and used to provide immediate protection against specific toxins.
Botulism Antitoxin: Protects against botulism toxins (types A, B, C).
Diphtheria Antitoxin: Provides immediate protection against diphtheria toxin.
What are the types of Vaccines, how they work & their limitations/risk
“Whole-Cell Vaccines*
Inactivated (Killed) Vaccines
What They Are: These vaccines use microorganisms that have been killed, so they can’t cause disease.
Effectiveness: They are effective but usually need multiple doses (boosters) to build up strong immunity.
Limitations: They often don’t stimulate all parts of the immune system effectively, such as cell-mediated immunity (CMI) and secretory IgA production, which is important for protection in mucous membranes like those in the gut and respiratory tract.
Examples: Polio (oral polio vaccine - OPV), rubella, influenza, gonorrhea, oral typhoid, and cholera vaccines.
Live Attenuated Vaccines
What They Are: These use live microorganisms that have been weakened so they can’t cause serious disease in healthy people.
Effectiveness: Usually, a single dose is enough to provide long-lasting immunity. They stimulate both humoral immunity (antibodies) and CMI.
Risks: They can cause vaccine-associated disease (VAD) in people with weakened immune systems.
Acellular or Subunit Vaccines
What They Are
These vaccines use only specific parts of the microorganism, not the whole microbe. This reduces some of the risks associated with whole-cell vaccines.
Recombinant-Vector and DNA Vaccines
Recombinant-Vector Vaccines
What They Are: Genes from a disease-causing microbe are inserted into a harmless virus or bacterium (the vector). The vector then replicates in the body, producing the microbe’s antigens.
How They Work: The immune system responds to these antigens by producing antibodies and CMI.
Examples of Vectors: Adenovirus and attenuated Salmonella.
DNA Vaccines
What They Are: These vaccines involve directly introducing DNA that codes for the microbe’s antigens into the host’s cells.
How They Work: The host’s cells take up the DNA and produce the antigens, which the immune system then responds to.
Advantages: They are very stable and don’t usually need refrigeration
Capsular Polysaccharide Vaccines
