types of immunity Flashcards
what are the different types of immunity
1) natural
2) artificial
3) active
4) passive
what is natural and artificial immunity
1) immunity gained in the normal course of living processes
2) immunity gained by deliberate exposure to antigens or antibodies
what is active and passive immunity
1) immunity caused by the introduction of an antigen
2) immunity caused by the introduction of a antibody
what is natural passive immunity
antibodies given in natural living processes for example via breastmilk or the placenta in order to make baby immune to same diseases as the mother until own antibodies are produced
what is artificial passive immunity
antibodies manually given to individual such as by an injection ie rabies or tetanus therefore deliberate exposed
what is natural active immunity
antibodies made by the individuals own immune system as a result of infection
what is artificial active immunity
antibodies made by an induvial own immune system as a result of a vaccination ie rubella
define vaccination
deliberate exposure to harmless antigenic material to activate the immune responce and antibodies and memory b cells which provided later immunity preventing individual from suffering the symptoms of the disease
what are the reasons some individuals will not receive a vaccination
1) immunocompromised ie chemotherapy patients, very old and young, HIV
2) religious objections
3) safety fears
why are vaccines not always effective
1) antigenic variation- different strains of the pathogen caused by mutation so antigens no longer recognised by immune system
2) antigenic concealment- parasites live within body cells so antigens aren’t seen
3) some individuals don’t have a strong enough immune system
define antigenic shift
mixing of antigens between similar strains of a virus changing the proportions and types resulting in a new strain
what is antigenic drift
genetic mutations leading to new different shaped antigens being produced and a new strain
