Vaccines Flashcards
Who are the key historical figures in immunology who led to the development of vaccines?
Edward Jenner in 1749-1823 who discovered the principle of vaccination using the cowpox virus
Louis Pasteur from 1822-1895 who determined that attenuated pathogens could be used as safe vaccines
Karl Landsteiner who discovered the different blood groups
George Snell who co-discovered MHC
What have been some of the successful vaccination campaigns?
Smallpox
Diptheria
Polio
Measles
What is key to developing a successful vaccine?
They must induce the production of high affinity neutralizing antibodies which can rapidly bind to the pathogen and prevent it from adhering to or entering host cells
What are the characteristics of a safe vaccine?
It has high efficacy through stimulation of a vigorous and appropriate T-dependent response leading to pathogen elimination by antibody or CTLs promoting the development of memory cells
It must be safe where the side effects of the vaccine are not worse than the natural disease symptoms
It must act against a pathogen which causes acute rather than chronic disease, induces immunity upon natural exposure, undergoes little antigen variation, does not attack immune system cells, does not have an animal or environmental reservoir
What are adjuvants?
They are factors which are required potentiate and amplify immune responses to vaccines
What are examples of live vaccines?
Smallpox, BCG, measles, mumps, rubella
What are examples of inactivated vaccines?
Typhoid, plague, cholera, hepatitis A
What are examples of subunit vaccines?
Anthrax, tetanus, Lyme disease
What may have encouraged the recent decline in vaccination?
The declining incidence of infectious disease
What is the major incentive for the development of safer more effective vaccines?
There is a need to maintain the level of vaccination at 75% to produce herd immunity, (the level of immunity at which the disease is unable to spread)
What are the features of the combined diphtheria/tetanus/pertussis vaccine?
It is a subunit vaccine based on chemically inactived toxins or toxoids from each bacterium combined with adjuvants
The toxoids have lost their toxic properties but retain their antigenic properties so the resulting antibodies are highly effective at preventing disease
How was a vaccine produced to the H1N1 flu?
Like traditional seasonal flu vaccines thei one was produced in Hens eggs with the H1N1 strain being injected into the eggs where it can multiply before it is harvested, purified and chemically inactivated so that it is capable of producing an immune response but not causing flu
These virus particles are then checked and added to the vaccine
It can take up to two eggs to produce one dose of vaccine
