Vaccinations Flashcards
What are vaccines
A way of introducing a small amount of weakened or dead pathogens to stimulate the production of antibodies and memory cells
How are vaccines long lasting
They produce memory cells that remain in the blood and produce complementary antibodies to the antigen in response to future infections
How are pathogens in viruses made harmless
- pathogens being killed but leaving the antigens unaffected
- weakened by heating but leaving the antigens unaffected
- purified antigens removed from pathogen
- using toxoids, harmless but tigger same immune response
Why may some people feel unwell after a vaccine
Because they contain foreign antigens there will still be a primary immune response, which can have symptoms like swelling, mild fever and runny nose
4 things that makes a successful vaccine
- economically available, many people can afford to stop spread
- few side effects
- easy storage and transport
- vast majority of population are available to take it, reach as many people as possible
4 ethical issues over vaccines
- tested on animals
- who should they be tested on first
- some people refuse due to side effects
- whether or not it should become compulsory to take it
Why do vaccinations not fullly eliminate diseases
- fails to make people immune in some people (their immune system doesn’t response as normal)
- people having a slow primary response
- antigenic variability, pathogens can mutate and vaccine becomes ineffective towards that variation
- objections too vaccinations, religious/ ethical issues
What is herd immunity
When a population can be protected from a certain virus if a large proportion of the population is vaccinated against it
How can herd immunity be achieved
By vaccinating a large amount of the population so that enough people are immune so slows down the spread, protecting those who cannot take the vaccine
Exam question: how can a vaccine lead to protection against said disease (bacterial meningitis)
B cells with specific antibodies bind to antigens.
T cells stimulate b cells to divide by mitosis forming clones, memory cells and plasma cells
Plasma cells release antibodies and memory cells provide long term protection as they can produce plasma cells and many antibodies
Exam question: when a vaccine is given to a person, describe how it leads to the production of antibodies against a disease causing organism
B cells with a specific antibody bind to antigens on the vaccine .
B cells become an apc
T cells with specific receptors bind to an antigen on an apc
So T cells stimulate b cells to divide by mitosis forming clones
Plasma cells secrete antibodies
And memory cells circulate in the blood providing long term protection
Exam question: describe how b lymphocytes respond when they are stimulated by antigens
They divide by mitosis to form clones, plasma cells which secrete antibodies and memory cells that stay in the body and provide long term protection
