active and passive + re-emergence Flashcards
what is active immunity?
when an individuals adaptive immune response responds to an antigen and produces specific antibodies, B and T cells and gains immunological memory
- requires involvement of individual adaptive immune system
- it is slow and develops overtime
how do you determine if the immunity is active or passive?
immunity is active or passive based on the origin of response
what is passive immunity?
short term immunity resulting from a person receiving antibodies produced from another organism/ the passive transfer of antibodies produced by another organism
- immediate response
- provides temporary protection
- transferred antibodies degrade overtime and are removed from the immune system
why is passive immunity lack long term immunity?
because the adaptive immune response won’t be activated and therefore no memory B and T cells will be created
what is are the types of immunity and acquisition of immunity?
types of immunity: active and passive
acquisition of immunity: artificial and natural
what is natural immunity?
natural immunity develops after natural encounters with a pathogen
what is artificial immunity?
develops after intentional introduction of antigens or antibodies into the body
what is natural active immunity?
an individuals response to a pathogen, that they produce specific antibodies for, that they have been exposed to. If individual were to encounter same pathogen in the future they would be immune to that pathogen because they have memory B and T cells
what is natural passive immunity?
passive transfer of antibodies from one organism to another that provides temporary protection -weeks or months.
- basically the transfer of antibodies from mother to foetus through placenta or through breastfeeding when the baby is born
what is active artificial immunity?
artificial active immunity is created when antigens or whole pathogens are intentionally introduced to induce an adaptive immune response (production of antibodies or memory B and T cells) through a vaccination for example
what is artificial passive immunity?
created when an individual receives antibodies or antiserum produced by another organism. Useful against bites that could cause death before an individuals adaptive immune response is activated
- transferred antibodies bind to antigens or toxins
- no immunological memory
- has time to suppress active immunity when it can be harmful
what is a vaccine?
material used to induce artificial immunity
what are the three types of vaccines?
live attenuated
inactive
subunit
what is a live attenuated vaccine?
contains weakened form of pathogen that causes the disease
- due to similarity between vaccine and natural pathogen, there is a strong adaptive immune response
- pathogen is still able to reproduce but not cause symptoms of the disease
- a single dose can initiate a strong adaptive immune response in those who are healthy but may cause disease in those with weakened immune systems
- can result in a lifetime protection against pathogen
- those with weakened immune systems may contract the disease
- live attenuated vaccines include measles mumps and rubella
what is an inactive vaccine?
uses a killed or non viable version of the pathogen
- the disease causing agent is unable to replicate
what are advantages of using an inactivated vaccine?
- results in production of many different antibodies as they contain different antigens
- safe for those with weak immune systems
disadvantages of inactivated vaccine?
- no life long immunity - therefore booster shots are needed in order to maintain long-term immunity by increasing memory B and T cell count
what is subunit vaccine?
uses specific pieces of the pathogen such as antigens, parts of antigens or a capsid: contains specific pieces of the pathogen selected for ability to induce an adaptive immune response
Those that contain multiple antigens induce broader immunity as they will induce production of antibodies against multiple antibodies
- examples include whooping cough and hepatitis B
what are advantages of subunit vaccine?
- safe for weak immune systems
- they are easier to store than live attenuated vaccines
what are disadvantages of subunit vaccine?
stimulates a weaker immune response therefore booster vaccines should be administered to maintain long term immunity