Flashcards in Principles of Immunisation Deck (35)
What are 2 examples of natural passive immunity?
-placental transfer of IgG
-colostral transfer of IgA
What are 2 examples of artificial passive immunity?
-treatment with immunoglobulin
What is human normal immunoglobulin?
contains all antibodies- protein extracted from pooled blood donations
What is human specific immunoglobulin?
selected blood donor with high antibody titres against a specific organism
When is HNIG used for post-exposure prophylaxis?
When are specific immunoglobulins used for post-exposure prophylaxis?
What is an advantage of passive immunity?
gives immediate protection
What are the disadvantages of passive immunity?
-short term: no immunological memory
-graft versus host disease
What is an example of natural active immunity?
What is an example of artificial active immunity?
What are the advantages of active immunisation?
-antigen stimulated immune response
-long term immunity
-faster and better response on second encounter
the administration of antigenic material to stimulate and individual's immune system to develop adaptive immunity to a pathogen
Why might someone not receive a vaccination?
-pregnant woman cannot receive live attenuated vaccines
-immunocompromised cannot be given live attenuated viruses
How does an immune response occur?
-disease causing organism contains antigens
-antigens stimulate the production of antibodies
-antibodies bind to the organism and lead to its destruction and memory B cells are formed
How are live attenuated vaccines made?
attenuation of a pathogenic organism by repeated passage in cell culture or a non-human host
Advantage of live attenuated vaccines
they elicit strong cellular and antibody responses and often confer lifelong immunity with only one or two doses
Disadvantages of live attenuated vaccines
-remote possibility exists that an attenuated microbe could revert to a virulent form and cause disease
How are inactivated vaccines produced?
by killing the disease causing microbe with chemicals, heat or radiation
Advantages of inactivated vaccines
-more stable and safer than live vaccines
-do not require refrigeration
Disadvantages of inactivated vaccines
stimulate a weaker immune system response than liv vaccines
-may require and adjuvant
-boosters likely required
What are 4 examples of inactivated vaccines?
What are acellular vaccines?
use only the antigenic part of the disease causing organism
What are the characteristics of acellular vaccines?
-don't induce the strongest immune response
-may require boosters
-cannot cause disease
When are toxoid vaccine used?
when a bacterial toxin is the main cause of illness- when bacteria secrete toxins or harmful chemicals
How are toxins inactivated?
treating them with formalin
What is an example of a toxoid vaccine?
DTaP (diphtheria, tetanus and pertussis)
What is a BCG?
a vaccine against Mycobacterium bovis to protect against Mycobacterium tuberculosis
What is a subunit vaccine?
-a vaccine that only includes the antigens that best stimulate the immune system
-in some cases they use epitopes- parts of the Ag that Ab or T cells recognise
What is a conjugate vaccine?
A vaccine which links antigens or toxoids from the microbe that an infant's immune system can recognise to polysaccharides