immunity Flashcards
what is active immunity?
the type of immunity you get when your immune system makes its own antibodies after being stimulated by an antigen
explain the 2 types of active immunity
NATURAL immunity: when you become immune after catching a disease
ARTIFICIAL immunity: when you become immune after you’ve been given a vaccination exposing you to a harmless dose of antigen
what is passive immunity
the type of immunity you get from being given antibodies made by different organism. Your immune system doesn’t produce its own antibodies
explain the 2 types of passive immunity
NATURAL: when a baby becomes immune due to the antibodies it receives from its mother through the placenta and in breast milk
ARTIFICIAL: when you become immune after being injected with antibodies from someone else. eg, getting an injection of antibodies against a toxin such as tetanus
compare passive and active immunity
passive doesn’t require exposure to an antigen, active: requires exposure to an antigen. In active, it takes a while for protection to develop, in passive protection is immediate. In active, memory cells are produced, they aren’t in passive. In active, protection is long term, in passive, protection is short term
when does herd immunity arise? what is it?
arises when a sufficiently large proportion of the population has been vaccinated (and therefore immune) which makes it difficult for a pathogen to spread within that population. Those who aren’t immunised are protected and unlikely to contract it
what induces artificial active immunity?
vaccinations
why is herd immunity a benefit?
it ensures that people who are vulnerable or cant receive the vaccine for medical reasons still have protection
what % of the population must be vaccinated to provide herd immunity to highly contagious diseases?
90%
what % of the population must be vaccinated to provide herd immunity to less contagious diseases?
80%
