Principles of Immunisation

Question 1

What are 2 examples of natural passive immunity?

Answer 1

• placental transfer of IgG

- colostral transfer of IgA

Question 2

What are 2 examples of artificial passive immunity?

Answer 2

• treatment with immunoglobulin

- immune cells

Question 3

What is human normal immunoglobulin?

Answer 3

contains all antibodies- protein extracted from pooled blood donations

Question 4

What is human specific immunoglobulin?

Answer 4

selected blood donor with high antibody titres against a specific organism

Question 5

When is HNIG used for post-exposure prophylaxis?

Answer 5

• hep A
• measles
• polio
• rubella

Question 6

When are specific immunoglobulins used for post-exposure prophylaxis?

Answer 6

• hep B
• rabies
• tetanus
• Varicella-Zoster virus

Question 7

What is an advantage of passive immunity?

Answer 7

gives immediate protection

Question 8

What are the disadvantages of passive immunity?

Answer 8

• short term: no immunological memory
• serum sickness
• graft versus host disease

Question 9

What is an example of natural active immunity?

Answer 9

exposure/infection

Question 10

What is an example of artificial active immunity?

Answer 10

vaccination

Question 11

What are the advantages of active immunisation?

Answer 11

• antigen stimulated immune response
• long term immunity
• immunological memory
• faster and better response on second encounter

Question 12

Vaccination

Answer 12

the administration of antigenic material to stimulate and individual’s immune system to develop adaptive immunity to a pathogen

Question 13

Why might someone not receive a vaccination?

Answer 13

• febrile illness
• pregnant woman cannot receive live attenuated vaccines
• allergy
• immunocompromised cannot be given live attenuated viruses

Question 14

How does an immune response occur?

Answer 14

• disease causing organism contains antigens
• antigens stimulate the production of antibodies
• antibodies bind to the organism and lead to its destruction and memory B cells are formed

Question 15

How are live attenuated vaccines made?

Answer 15

attenuation of a pathogenic organism by repeated passage in cell culture or a non-human host

Question 16

Advantage of live attenuated vaccines

Answer 16

they elicit strong cellular and antibody responses and often confer lifelong immunity with only one or two doses

Question 17

Disadvantages of live attenuated vaccines

Answer 17

• remote possibility exists that an attenuated microbe could revert to a virulent form and cause disease
• require refrigeration

Question 18

How are inactivated vaccines produced?

Answer 18

by killing the disease causing microbe with chemicals, heat or radiation

Question 19

Advantages of inactivated vaccines

Answer 19

• more stable and safer than live vaccines

- do not require refrigeration

Question 20

Disadvantages of inactivated vaccines

Answer 20

stimulate a weaker immune system response than liv vaccines

• may require and adjuvant
• boosters likely required

Question 21

What are 4 examples of inactivated vaccines?

Answer 21

• bubonic plague
• typhoid
• hep A
• rabies

Question 22

What are acellular vaccines?

Answer 22

use only the antigenic part of the disease causing organism

Question 23

What are the characteristics of acellular vaccines?

Answer 23

• don’t induce the strongest immune response
• may require boosters
• cannot cause disease

Question 24

When are toxoid vaccine used?

Answer 24

when a bacterial toxin is the main cause of illness- when bacteria secrete toxins or harmful chemicals

Question 25

How are toxins inactivated?

Answer 25

treating them with formalin

Question 26

What is an example of a toxoid vaccine?

Answer 26

DTaP (diphtheria, tetanus and pertussis)

Question 27

What is a BCG?

Answer 27

a vaccine against Mycobacterium bovis to protect against Mycobacterium tuberculosis

Question 28

What is a subunit vaccine?

Answer 28

- a vaccine that only includes the antigens that best stimulate the immune system - in some cases they use epitopes- parts of the Ag that Ab or T cells recognise

Question 29

What is a conjugate vaccine?

Answer 29

A vaccine which links antigens or toxoids from the microbe that an infant's immune system can recognise to polysaccharides

Question 30

What problem do conjugate vaccines solve?

Answer 30

- many harmful bacteria have an outer coating of polysaccharides - -polysaccharide coatings disguise bacterial antigens so that the immature immune system of infants and children can't recognise or respond to them

Question 31

What do conjugate vaccines defend against?

Answer 31

- hepB - hib - pertussis - HPV

Question 32

How do DNA vaccines work?

Answer 32

- use only genetic material - when the genes for a microbe's antigens are introduced into the body, some cells will take up that DNA and some cells make the antigen molecules. - the cells secret the antigens and display them on their surfaces - this evokes a strong antibody response to the free-floating antigen secreted by cells - stimulates a strong cellular response against the microbial antigens displayed on cell surfaces

Question 33

Adjuvant

Answer 33

a substance which enhances the body's immune response to an antigen

Question 34

What is the primary aim of vaccination?

Answer 34

to protect the individual who receives the vaccine

Question 35

How does herd immunity occur?

Answer 35

- Vaccinated individuals are less likely to be a source of infection to others - this reduces the risk of unvaccinated individuals being exposed to infection - therefore individuals who cannot be vaccinated will still benefit from routine vaccination programmes