Immunity and vaccines Flashcards
What do vaccines give you?
Immunity without any symptoms
What do vaccines contain and what do they do?
Antigens that will be either free or attached to a dead or attenuated pathogen. This causes the body to produce memory cells against a pathogen without it causing a disease
What does antigenic variation do?
Makes it difficult to develop vaccinations for some pathogens
Explain antigenic variation
Different antigens are formed due to changes in the gene of a pathogen. When infected for a 2nd time the memory cells from the 1st infection will not recognise the different antigens
What is antigenic concealment?
When pathogens hides from an immune system by either living inside cells or coating body in the host’s protein
Name ethical issues and problems surrounding vaccines
Tested on animals
Testing on humans poses a big risk
Side effects
Use of animal based substances
If there is an epidemic and a vaccine rush, then who gets the vaccine first
What is herd immunity?
When people without vaccines are protected from diseases due to the high number of the population being vaccinated. This reduces the occurrence of diseases in unvaccinated people
What is active immunity?
When the immune system makes it own antibodies after being stimulated by an antigen
What is natural active immunity?
When you become immune after catching a disease
What is artificial active immunity?
When you become immune after have a vaccination
Describe the characteristics of active immunity
Requires exposure to antigen
Take a while for protection to develop
Memory cells are produced
Provides long term protection
What is passive immunity?
Immunity from being given antibodies by a different organisms
What is natural passive immunity?
When a baby becomes immune due to the antibodies it receives from its mother through the placenta and breast milk
What is artificial passive immunity?
Immunity you get from being injected with antibodies from someone else
Describe the characteristics of passive immunity
Doesn’t require exposure to antigen
Protection is immediate
Memory cells aren’t produced
Protection is short-term
