Vaccinations flashies Flashcards
purpose of vaccines
provide an individual with the PRIMARY immune response to pathogen- so if exposed again you have memory without having contracted the disease
population–> eradication of disease, control of infectious diseases worldwide
factors allowing vaccines to be effective?
- doesn’t cause latency
- doesn’t have much antigenic variation- b/c then the vaccination would be worthless
- doesn’t interfere with host immune response- doesn’t down regulate immune response
vaccines also most effective against infections that are limited to human hosts
herd immunity
sufficient number of immune individuals in a population-to stop transmission of infection
**proportion depends on severity of infection (so if the infection is very easily infectious, then a high proportion of the population must be immune to maintain herd immunity)
passive immunization
uses pre-synthesized antibodies (human Ig’s) -prevent disease after known exposure
- protect immunosuppressed patients
- ex/ snake bite anti-venom (IgG that is specific for venom)
also, passive transfer of mom Abs to child
active immunization
delayed but more permanent
example is natural exposure to pathogens and vaccines
combined passive-active immunization
give immediate and lasting protection
ex/ tetanus,
rabies**must be given in different sites of body so they don’t combine with each other
how to make vaccine?
whole or part of microorganisms administered to prevent infectious disease
isolate something that:-does not cause disease-does cause immune response
types of vaccines?
acellular
killed organisms
attenuated-
toxoid
mimic
subunit
DNA plasmid
killed organism vaccine?
inactivated or killed microorganism
ex/ polio
acelllular vaccine?
use antigen part of disease causing organism
ex/ DTap
attenuated vaccine?
can be attenuated by environmental conditions or genetic engineering
reduce virulence but still keep it viable
toxoid vaccine?
made from inactivated toxic compounds that cause illness rather than the micro-organism
ex/ tetanus
mimic vaccine?
use organisms similar to virulent one but doesn’t cause harm
ex/ vaccinia, BCG for M. tuberculosis
subunit vaccine?
utilizes techniques of genetic engineering
requires adjuvant (keeps vaccine in certain area)
uses subunit of virulent organism
DNA plasmid vaccine?
mimics live attenuated vaccine preparation-circular DNA plasmids expressing specific proteins injected with presentation of protein to immune system
ex/ HIV in developmentvaccinia vector
thimersol
used as preservative in vaccines
can be converted to methyl-mercury (neurotoxin)
no longer used
adjuvants
bring antigen into contact with immune system and keep the subunits flocked in the area so the APC can pick them up
decrease the toxicity of certain antigens
provide solubility to some vaccine components
aluminum hydroxide
only FDA approved adjuvant
clumps with antigen to keep it at the injection site
immunization schedule for child
produce immunity to virulent organisms likely to be encountered early in life
consider:
-timing of likely exposure
- immunological maturity of child
- passively transferred antibodies
- boosters for priming
parenteral route?
subQ, IM, or intradermal
stimulates IgG
oral route?
stimulates IgA (b/c IgA is associated with mucosal immunity)
contraindications to immunization?
febrile illness
immunosuppressive therapy
recent blood transfusion
simultaneous vaccination of another vaccine
immunodeficiency
pregnancy
leukaemia or lymphoma
vaccines for special populations?
influenza - children and elderly
hep A, typhoid, west nile, yellow fever - travelers
rabies - animal workers
adverse reaction to vaccines?
not totally safe-
no perfect vaccine **
undesirable side effects
new vaccine strategy?
use recombinant DNA technology
Potential problems with vaccines
clinically important epitopes may not be intact in vaccine
individual genetics may effect efficacy
some individuals may be genetically predisposed to adverse events
often work poorly in young infants or the elderly b/c they have an immunosuppression
development of immune response to vaccine depends on ….
route
timing
use of adjuvants
previous exposure to infection
