Difference between revisions of "Vaccines"

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*Long duration of action
 
*Long duration of action
  
==What antigens do we use in the vaccine?==
+
==What antigen(s) do we use in the vaccine?==
 +
 
 +
'''Whole Organsim'''
 +
 
 +
*Live attenuated organism
 +
**Virulent organisms cannot be used as vaccines as they would cause disease
 +
**Virulence is reduced by growing the organism in altered conditions so that it is less able to replicate when introduced to the host and therefore less likely to cause disease
 +
 
 +
*Killed inactivated organism or toxin (toxoid)
 +
**Virulent and toxic organisms cannot be used as vaccines as they would cause disease
 +
**Organisms can be killed using radiation or chemicals so that they still posess the antigens to stimulate an immune response, but the organisms are unable to replicate inside the host
 +
**Toxins are inactivated to produce a toxoid which will still have the antigens needed to produce an immune reponse but will not be harmful to the host
 +
**Needs two doses
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 +
'''Subunit Vaccine''' (part of the organism)
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 +
*Purified protein
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**From lysed organisms
 +
 
 +
*Recombinant or synthetic protein
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**The gene for the antigen required is inserted into a virus vector or cloned into bacteria
 +
**Small antigens, such as peptides can be synthetically produced
 +
 
 +
*DNA coding for proteins (antigens)
 +
**Can be vaccinated directly into the host
  
 
==Links==
 
==Links==

Revision as of 16:24, 25 August 2008

BACK TO IMMUNOLOGY
BACK TO HOST INVASION BY MICROORGANISMS


Why Vaccinate?

  • To protect against infectious diseases
  • Where there is no effective treatment once infected
    • E.g. FeLV, FIV
  • Where disease is life-threatening
    • E.g. Canine Parvovirus
  • To prevent the spread of disease
    • E.g. Rabies, FMDV

How do we vaccinate?

  • Usually by subcutaneous injection for systemic protection (IgG)
  • For mucosal immune reponse, intranasal administration is best (IgA)

What do we vaccinate with?

Passive Immunisation - Copyright nabrown RVC

Passive immunisation

  • Administer antibodies
    • Maternally-derived antibodies in colostrum
    • Antiserum (artificial)
  • Immediate protection
  • Short duration of action
Active Immunisation - Copyright nabrown RVC

Active immunisation

  • Administer antigen so the patient's own antibodies protect against disease
    • Living organisms
    • Dead organisms
    • Toxoids
    • Subunit antigens
    • DNA
  • Delay in protection
  • Often needs two or more doses
  • Long duration of action

What antigen(s) do we use in the vaccine?

Whole Organsim

  • Live attenuated organism
    • Virulent organisms cannot be used as vaccines as they would cause disease
    • Virulence is reduced by growing the organism in altered conditions so that it is less able to replicate when introduced to the host and therefore less likely to cause disease
  • Killed inactivated organism or toxin (toxoid)
    • Virulent and toxic organisms cannot be used as vaccines as they would cause disease
    • Organisms can be killed using radiation or chemicals so that they still posess the antigens to stimulate an immune response, but the organisms are unable to replicate inside the host
    • Toxins are inactivated to produce a toxoid which will still have the antigens needed to produce an immune reponse but will not be harmful to the host
    • Needs two doses

Subunit Vaccine (part of the organism)

  • Purified protein
    • From lysed organisms
  • Recombinant or synthetic protein
    • The gene for the antigen required is inserted into a virus vector or cloned into bacteria
    • Small antigens, such as peptides can be synthetically produced
  • DNA coding for proteins (antigens)
    • Can be vaccinated directly into the host

Links

Creators

Natalie Brown

BACK TO IMMUNOLOGY
BACK TO HOST INVASION BY MICROORGANISMS