Immunity and Vaccines Flashcards
Innate Immunity
the defensive mechanisms that exist naturally and before the infection occurs.
Natural defenses against pathogens, and provides the first line of defense just after exposure of hte host to the pathogen.
- Anatomical barriers
- skin
- mucous membranes
- Physiological Bacciers
- stomach acid
- enzymes
- Phagocytosis
- Inflammation
Adaptive Immunity
Is capable of recognizing and selectively eliminating specific microorganisms and molecules.
Ummine response mounted is specific to the antigens that triggered the immunity.
Can be antibody-mediated (humoral) or Cell-mediated (cellular)
Immunodeficiency
Any defect in the immune system that results in failure to recognize and respond adequately to antigenic stimulation.
More susceptible to infection
could be genetic or acquired as a consequence of infection
Immunocompromised Host
Caused by specific or non-specific immunity defects. Hosts are at an increased risk of infection, including microorganisms that are not pathogenic to healthy individuals.
Immune system may be compromised because of stress, cancer, radiation. chemotherapy, immunosuppressive drugs, etc.
Antigen
Substance the body recognizes as foreign and mounts an immune response
Also called Immunogen.
Antibodies or Immunoglobulins
Produced in response to antigenic stimulation.
y-shaped protein molecules composed of four polypeptide chains. two light chains and two heavy chains.
Polyclonal Antibodies
immune response to an antigen usually results in the production of antibodies directed at numerous determinants ro epitopes.
Resulting antiserum has mixture of antibodies, against multiple epitopes
Monoclonal Antibodies
Each Ig is produced by a single B cell and B cells cloned in vitro can produce limitless supplies of a single monospecific Ig.
Humoral Immunity
Carred out by antibodies ciculating in the blood or in secretions.
Production is initiated by antigenic stimulation of B lymphocytes.
More common response in bacterial infections
Cell-mediated Immunity
Carried out at a cellular level in situations where antigens are embedded in celll membranes or inside host cells.
Initiated by T lymphocytes.
More common in fungal or viral infections
Passive Immunization
administration of antibodies or antibody-containing serum to an animal for the rapid, transient protection or treatment of infection
Naturally acquired
Antibodies made by the mother’s immune system are transferred to the offspirng via placental transfer or colostrum
Artificially Acquired
Antibodies produced in another host is introduced into a new host.
Active Immunization
Immune response is stimulated in response to administration of an antigen such as exposure to an infectious agent or vaccine.
Vaccine
a suspension of organisms or components of organisms that is injected to induce immunity to protect against the infection.
Response to vaccination mimics the immunity that develops naturally in animals that have recovered.
Live vaccines
Prepared with organisms limited in their ability to cause disease.
Attenuated vaccines contain bacteria that are weakened so that they do not cause the disease but are still able to grow.
- Vaccine may be infective to immunocompromised animals
- vaccine may revert to a virulent form.
Most used against viral diseases.
Inactivated Vaccine
provide a large amount of antigen to produce a protective antibody response without the risk of infection by the organism.
inactivation process alters the antigen, immune response is weaker.
Killed Whole Cell vaccine (Bacterin)
advantage with bacterin is it is easy to make. Disadvantage is that the vaccine contains many unwanted and extraneous material and some of them could elicit injection site reactions or injury.
Subunit Vaccine
Vaccine containing cell components.
Used in cases wehre a single component of a cell is sufficient to induce antibodies needed to protect the animals against the infection.
Such bacterial antigens that can induce protective antibodies are called Protective antigen
Toxoid
an inactivated toxin.
DNA vaccines
Another form of active immunization.
New and promising approach.
Has not yet resulted in any comercial vaccines.
Plasmid DNA is injected into muscle or skin , after which it expressed the gene for the antigen.
Protein expressed stimulates an immune response.
DNA remains effective only until it is degraded.
West Nile vaccine in horses
