Immunity and Vaccines

Question 1

Innate Immunity

Answer 1

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.

1. Anatomical barriers
   
   1. skin
   2. mucous membranes
2. Physiological Bacciers
   
   1. stomach acid
   2. enzymes
3. Phagocytosis
4. Inflammation

Question 2

Adaptive Immunity

Answer 2

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)

Question 3

Immunodeficiency

Answer 3

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

Question 4

Immunocompromised Host

Answer 4

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.

Question 5

Antigen

Answer 5

Substance the body recognizes as foreign and mounts an immune response

Also called Immunogen.

Question 6

Antibodies or Immunoglobulins

Answer 6

Produced in response to antigenic stimulation.

y-shaped protein molecules composed of four polypeptide chains. two light chains and two heavy chains.

Question 7

Polyclonal Antibodies

Answer 7

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

Question 8

Monoclonal Antibodies

Answer 8

Each Ig is produced by a single B cell and B cells cloned in vitro can produce limitless supplies of a single monospecific Ig.

Question 9

Humoral Immunity

Answer 9

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

Question 10

Cell-mediated Immunity

Answer 10

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

Question 11

Passive Immunization

Answer 11

administration of antibodies or antibody-containing serum to an animal for the rapid, transient protection or treatment of infection

Question 12

Naturally acquired

Answer 12

Antibodies made by the mother’s immune system are transferred to the offspirng via placental transfer or colostrum

Question 13

Artificially Acquired

Answer 13

Antibodies produced in another host is introduced into a new host.

Question 14

Active Immunization

Answer 14

Immune response is stimulated in response to administration of an antigen such as exposure to an infectious agent or vaccine.

Question 15

Vaccine

Answer 15

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.

Question 16

Live vaccines

Answer 16

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.

1. Vaccine may be infective to immunocompromised animals
2. vaccine may revert to a virulent form.

Most used against viral diseases.

Question 17

Inactivated Vaccine

Answer 17

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.

Question 18

Killed Whole Cell vaccine (Bacterin)

Answer 18

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.

Question 19

Subunit Vaccine

Answer 19

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

Question 20

Toxoid

Answer 20

an inactivated toxin.

Question 21

DNA vaccines

Answer 21

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