Week 3 - Immunity and Vaccines

Question 1

Name the four types of acquired immunity

Answer 1

• Natural:
  ○ Active (encountering antigen)
  ○ Passive (antibody transfer by natural means)
• Artificial:
  - Active (vaccination)
  - Passive (antibody transfer by artificial means)

Question 2

How is immunity reached for Natural, Active?

Answer 2

Immunity gained through illness and recovery, enters the body naturally

Question 3

How is immunity reached for Natural, Passive?

Answer 3

Immunity acquired from antibodies passed in breastmilk or through placenta

Question 4

How is Immunity reached for Artificial, Active?

Answer 4

Immunity gained through a vaccine

Question 5

How is immunity reached for Artificial, Passive?

Answer 5

Immunity gained through antibodies harvested from another person or an animal

Question 6

Name the four different types of vaccines

Answer 6

• Live, attenuated (weakened) microbes
• Killed whole microbes
• Portions of microbes
• Toxoids (inactivated toxins)

Question 7

Identify which type of vaccine would give the most effective response

Answer 7

Live, attenuated vaccine would give the most effective response

Question 8

Why would the Live vaccine give the most effective response?

Answer 8

Because they often provide lifetime immunity without the need for boosters

Question 9

State the purpose of vaccines

Answer 9

A vaccine stimulates your immune system to produce antibodies, exactly like it would if you were exposed to the disease. After getting vaccinated, you develop immunity to that disease, without having to get the disease first.

Question 10

Explain why a booster vaccine might be needed

Answer 10

Needed to intensify the immune response of a killed whole bacterial cells, toxoids, inactivated microbes or sub-units as the immune system does not respond as powerfully as when a live attenuated vaccine is given.

Question 11

Describe the concept of herd immunity

Answer 11

Results when most of a population is immune to the disease, If most people are immune then they won’t be carriers. It is protecting those who aren’t immune

Question 12

List the undesirable responses of the immune system

Answer 12

• Hypersensitivity reaction
• Autoimmune disorder
• Immuno-compromised
• Reactions to transported or foreign tissues
• Chronic inflammation

Question 13

Describe ‘Hypersensitivity reaction’

Answer 13

Allergy is a hypersensitivity to an environmental antigen.
Anaphylaxis is the most severe & rapid reaction. It is life- threatening as it causes constriction of the bronchial smooth muscle and oedema of the throat

Question 14

Describe ‘Autoimmune disorder’

Answer 14

The immune system attacks the body’s own cells when it fails to recognise ‘self’ e.g. rheumatoid arthritis

Question 15

Describe ‘Immunocompromised’

Answer 15

Persons are at risk from minor infections;

- Very young, elderly, severe illness , stress

Question 16

What are ‘reactions to transported or foreign tissues’?

Answer 16

Including blood transfusion reactions, donated organs etc

Question 17

Describe ‘Chronic inflammation’

Answer 17

Underlying cause of asthma or arteriosclerosis

Question 18

Describe the age related changes to the immune system

Answer 18

1. The new-borns’ immune system becomes stronger during encounters with both harmful & harmless microbes.
   - excessive use of antibiotics & antibacterial
   agents may prevent normal development (over
   use of antibacterial products e.g. Dettol)
2. With advancing age people become more susceptible to infection
   - Response to vaccines and infections is
   decreased as less antibodies are produced
   resulting in a slower response.
   - Older people are therefore more susceptible
   to infection

Question 19

What is vaccination the most effective against?

Answer 19

Controlling viral diseases

Question 20

Who should Live vaccines NOT be given to?

Answer 20

• Immunocompromised people (could cause disease)

- Pregnant people (Risk to the fetus)

Question 21

What are some side effects to vaccines?

Answer 21

• Most commonly Redness and swelling at the injection site, pain and mild fever
• Rare occasions - allergic reactions

Question 22

What is the advantage of a Live vaccine?

Answer 22

More likely to produce strong antibody & cellular response & long-lasting immunity.

Question 23

What is the disadvantage of a live vaccine?

Answer 23

Minute risk that the organism might mutate back to a virulent strain.

Question 24

What is the disadvantage of a killed microbe vaccine?

Answer 24

Does not provoke the immune response as strongly as a live microbe.

Question 25

Can the organism multiply with a killed microbe vaccine?

Answer 25

No, the organism is dead

Question 26

Why is the ‘portions of microbe’ (Subunit) a safe vaccine?

Answer 26

Because the organism cannot reproduce

Question 27

What is the toxoids vaccine?

Answer 27

Inactivated toxins

Question 28

What does the toxoids vaccine stimulate?

Answer 28

The immune system to produce antitoxins

Question 29

What are antitoxins?

Answer 29

Antibodies which inactivate toxins

Question 30

What is the disadvantage of using a toxoids vaccine?

Answer 30

Toxoid vaccines are non-living and therefore need several boosters to produce strong effective immunity.

Question 31

After recovering from certain diseases, one may have developed what type of immunity?

Answer 31

Naturally acquired active