Vaccination 101 Flashcards
What are two features of diseases that can be controlled by vaccines?
1) poorly infectious 2) antigens relatively invarient
What are three features of diseases that are difficult to control by vaccines?
1) highly infectious 2)antigenic variation 3) animal/enviromental reservoirs of infection
What are three aims of vaccination?
to induce specific immunity to 1)prevent microbial invasion 2) eliminate microbes 3)neutralize microbial toxins
Quickly run through history of vaccines
smallpox immunisation - infection with scab to induce immunity. then in other areas of the world till made illegal in 1842. cowpox to fight smallpox.
When was the molecular era?
1970-1990
Hepatitis B vaccine?
1981 using recombinant DNA technology
What is the future of vaccines?
HIV/AIDS, malaria, TB, anti-cancer, anti addiction etc
What is prophylactic immunization based on?
Immunologic memory - the ability of the immune system to ‘remember’ the vaccine
What are four ‘activating agents’ immunogen molecules?
peptides, polysaccharides, nucleic acids and lipids
what are four activating agent immunogen microorganisms?
bacteria, viruses, fungi and protozoa
What are the two artificial methods of immunity?
active and passive immunization
What is active immunization?
patient mounts a protective immune response
what is passive immunization?
patient aquires immunity through transfer of abs
what are the three types of vaccine for active immunization?
attenuated (live) vaccines, inactivated (killed) vaccines and toxoid vaccines
What is a toxoid vaccine?
a vaccine made from the toxins the mo secretes that cause the illness, rather than the mo itself
facts about attenuated vaccines
It uses active pathogenic microbes to create a small infection, leading to a strong immune respose. it only requires one dose, and can create contact immunity, however it’s hazardous.
Facts about inactivated vaccines
these can ether be whole agent vaccines or subunit vaccines. it is safer than live vaccines but antigenically weak and often contain adjuvants which enhance the bodies immune response
what is an adjuvant?
enhances the bodies immune response
Give four examples of inactivated vaccines
viruses, bacteria, protein based or poly based
give two common adjuvants and their effects
aluminium phosphate slows the processing and degradation of the antigen and saporin stimulates t cell responses
what is saporin/what does it do?
a plant product used as an adjuvant that stimulates t cell responses
what is aluminium phosphate used for?
to slow the processing and degradation of antigens
facts about toxoid vaccines?
modified toxins that are useful for some bacterial diseases and instigate antibody-mediated immunity, but require multiple doses.
what kind of immunity do toxoid vaccines instigate?
antibody mediated
what has recombinant gene therapy got to do with actve immunization?
research attempts are being made to make more effective, cheaper, safer vaccines. and recombinant gene therapy is a technique being looked into
what are four methods of using recombinant gene technology to create vaccines?
1) detecting the virulence gene in a pathogen and modifying it to create a harmless pathogen 2) isolating the DNA coding for the antigen, inserting into intermediate cell which synthesizes the antigen 3)isolating DNA coding for antigen, inserting it into a virus or other cell which presents it and 4) isolating dna coding for antigen, inserting it into a plasmid vector and inserting vector into cell which makes antigen.
What are problems associated with immunization?
mild toxicity, pain, anaphylaxis, virulence and autism
What is the method of PASSIVE immunisation?
admin of antiserum as immediate protection against a recent infection or an ongoing disease
what are 3 limitations to passive immunisation?
serum sickness, may be contaminated with the virus, abs degrate quickly
How may the limitations to passive immunisation be overcome?
hybridomas, which are formed by fusing plasma cells and myeloma cells to produce antibodies
What is the main difference between passive and active immunisation?
passive results in a huge amount of abs immediately, quickly degrading to 0 whilst active steadily builds up # of abs aided by boosters till the body KNOWS
What are four of WHOs properties of an ideal vaccine?
safe, affordable, heat stable and effective to a single dose.
