Flashcards in Vaccines Deck (52):
What is the main benefit of using vaccines compared to pharmaceuticals?
What had its last natural case in 1997 and is now eradicated in the natural world?
Name two things that can cause a reverse in the vaccine system?
Poor patient compliance, poor sanitation
What three diseases have had a 100% decrease in incidence post vaccination?
What two diseases have had a 99% decrease in incidence post vaccination?
What disease caused the 'iron lung' to be common in the 1950's and why was this lung necessary?
Poliomyelitits. The iron lung was necessary as diaphragm muscles were damaged causing paralysis and breathing difficulties.
Poliomyelitits outbreaks were most common in which social group?
Poliomyelitis most commonly caused paralysis of the diaphragm muscles. What other muscles could it paralyse?
Why do vaccines still need to be developed?
As we are still being exposed to new threatening agents.
Why is Ebola a hard organism to work on?
As it is contaminant level 4. Only 5 places in the UK can deal with this.
What do Ebola and HIV have a substantial impact on?
The economy (human capital).
What is the death rate of Ebola?
Modern transport hubs mean we are never ___ away from a large population centre. This is a serious problem with disease outbreaks.
Describe what is meant from Variolation.
Variolation involved inoculating people with the pus from Smallpox patience. This could provide immunity against smallpox but had a 20% fatality. It was hoped that only a mild case of the disease would be acquired.
What two ancient populations were aware of gaining immunity after pre exposure?
Ancient Greeks (429 bc) and the Chinese (900 AD).
Who based their ideas on Variolation?
What did Edward Jenner do?
Inoculated a young boy with pus from a cowpox lesion to prevent against smallpox. This provided a 'mock infection'.
Who developed the concept that microorganisms are a source of disease/ infection?
Who developed Germ Theory?
What did Louis Pasteur most famously develop a vaccine for?
What is the main concept of germ theory?
Weakened pathogens are generated to artificially infect subjects.
What is the definition of Active Immunisation?
The maniupaltion of the immune system to produce a persistant and protective response against the pathogen.
What three things must Active Immunisation do?
1. Safely mimic a natural infection to trigger an immune response.
2. Mobiles the appropriate arms of the immune system.
3. Generate immunological memory.
What cells are stimulated via active immunisation?
B and T lymphocytes.
What is the definition of passive immunisation?
The transfer of preformed antibodies into circulation.
What type of immunisation can be natural or artificial?
How does natural passive immunity occur?
Maternal antibodies transfer across the placenta to the developing foetus in the prenatal period.
Name two diseases that are vaccinated via passive immunity?
The transfer of preformed antibodies can be used in vaccines. When else can this occur (2 occasions)?
2. Treat those in an immunocompromised state
Although the body can mount an immune response against toxins and venom via antibody production however this response is not substantial. Why?
As it takes too long.
Preformed IgG is used as an anti venom/anti toxin. How is this usually obtained?
Sometimes toxins produced by microorganisms are lethal before the microorganism can be lethal itself. Name an example of this.
Botulinum toxin - 1.5ng/kg intravenously is lethal.
What is the definition of a toxioid?
A chemically modified toxin from a pathogenic microorganism. This is no longer toxic but is still antigenic.
Name three advantages of passive immunisation?
1. Quicker than a natural immune response.
2. Limits infection of highly virulent pathogens.
3. When no vaccine is available preformed antibodies can be the only cause of treatment.
What are the three drawbacks of passive immunisation?
1. Does not activate immunological memory.
2. No long term protection.
3. Cross reactions can occur with antisera if from a different species.
What three antibodies are used prophylatically to reduce the chance of establishing infection?
What is the main goal of active immunisation?
To remove the need of the primary exposure.
Active immunsiation aims to remove the need for primary exposure. What two other things does it aim to do?
1. Induce immunological memory.
2. Produce high affinity antibodies against the antigen.
The importance of what type of response varies depending on the pathogen?
What are four features of a perfect vaccine?
1. Long term protection
2. Stimulate B and T cells
3. Induce memory B and T cells
4.Stimulate protective IgG production.
Why do you need boosters of the flu vaccine (2 main reasons)?
1. Annual 'escape variants.
2. Need a high level of preformed IgG in circulation.
What can sometimes be established before immunological memory is activated?
Why do you need high levels of IgG in circulation in order for a flu vaccine to work?
The AB physically blocks the influenza virus from infecting tissues.
What is the first stage of any immunisation?
To activate the innate immune system.
The second stage is to then trigger the adaptive which produces T and B memory cells.
What two forms of whole organisms can be used as a vaccine?
Live attenuated and killed inactivated.
Live attenuated viruses are good vaccines. Why?
They stimulate all features of an infection.
What can killed/ inactivated vaccinations not do?
How can you kill or inactivate a pathogen.
Heat or chemical treatments.
Name four examples of subunit vaccines.
2. Antigenic extracts
3. Recombinant proteins
4. Conjugate vaccines
Other than whole organisms and subunit vaccines what else can be used as vaccines?
Peptides, DNA and Engineered viruses.
What is an adjuvant?
A substance that is added to the vaccines to stimulate the immune response.