Vaccines

Question 1

What is a vaccine

Answer 1

A suspension of antigens to induce artificial active immunity

Question 2

What are the two main types of vaccine

Answer 2

Live attenuated and Inactivated

Question 3

How do vaccines produce long - term immunity

Answer 3

They cause memory cells to be created. When reencountering an antigen, the body then produces antibodies, in a faster, stronger secondary response

Question 4

What is artificial active immunity

Answer 4

A specific immune response where antibodies are released by plasma cells

Question 5

How effective are vaccines

Answer 5

Most are effective with one vaccination giving a lifetimes protection (less effective ones require booster)

Question 6

How harmful are vaccines

Answer 6

Generally harmless - do not cause the disease they protect against because the pathogen is killed by the primary immune response

Question 7

How can someone have a poor response to a vaccine

Answer 7

If they are malnourished and cannot produce the antibodies proteins or their immune system may be defective

Question 8

How can antigenic variation cause an issue with vaccines

Answer 8

The variation in the antigens of pathogens causes the vaccines to not trigger an immune response or diseases caused by eukaryotes e.g. malaria have too many antigens

Question 9

How can antigenic concealment cause an issue with vaccines

Answer 9

Pathogens ‘hide’ from the immune system by living inside cells or when the pathogen coats in host proteins or by parasitising immune cells

Question 10

who discovered the principles underpinning vaccinations and when

Answer 10

Edward Jenner in the 1700s when he developed the smallpox vaccine

Question 11

How do live attenuated vaccines work

Answer 11

These contain whole pathogens, these weakened pathogens multiply slowly, the body recognises the antigens and triggers the primary immune response, these vaccines often produce a longer - lasting immune response

Question 12

How do inactivated vaccines work

Answer 12

Contain whole pathogens that have been killed or small parts of pathogens. However, these vaccines don’t trigger a strong or long lasting immune response (booster doses often required).

Question 13

Why may some people have allergic reactions or local reactions to vaccines

Answer 13

Adjuvants (e.g. aluminium salts) may be conjugated (joined) to the subunit of the pathogen to strengthen and lengthen the immune response

Question 14

When does herd immunity arise

Answer 14

When a sufficiently large proportion of the population has been vaccinated

Question 15

What does herd immunity do

Answer 15

Makes it difficult for a pathogen to spread within a population

Question 16

How do those who are not immunised stay protected using herd immunity

Answer 16

they are unlikely to contract the disease the population is vaccinated against as levels of disease are so low

Question 17

Why is herd immunity important

Answer 17

allows for individuals who are unable to be vaccinated to be protected

Question 18

Do proportions of population that need to be vaccinated to achieve herd immunity vary between different diseases

Answer 18

Yes

Question 19

How does eradicating disease present a challenge

Answer 19

Some pathogens are complicated and present with disease processes that aren’t straight forward, so a vaccine could not be developed. Diseases that can be eradicated and have a vaccine, haven’t been because too few people have had the vaccine.

Question 20

What economical reasons make eradicating disease challenging

Answer 20

Unstable political situations. Lack of public health facilities.

Question 21

Has small pox been eradicated

Answer 21

yes

Question 22

What is smallpox

Answer 22

A highly contagious disease caused by a virus that exists in two forms.

Question 23

What are the two forms of smallpox and which is the worst

Answer 23

Variola Minor and Variola Major, the latter being the worst with a death rate of 12-30%

Question 24

How was smallpox transmitted

Answer 24

Direct contact

Question 25

Symptoms of smallpox

Answer 25

Red pus filled spots over entire body

Question 26

what was aftermath of smallpox

Answer 26

people were disfigured from scabs and it also affected the eyes resulting in permanent blindness.

Question 27

When did the WHO begin their eradication programme against smallpox

Answer 27

1967

Question 28

What did the WHO’s eradication programme focus on

Answer 28

Vaccination - Aim to vaccinate more than 80% of populations at risk. If a case of smallpox was reported ring vaccination would occur. Surveillance - Neighbours would watch for signs of smallpox

Question 29

What is ring vaccination

Answer 29

Where everyone in the household with a reported case, the surrounding 30 households, relatives and anyone who had contact would get vaccinated.

Question 30

What was the success of the eradication of smallpox attributed to

Answer 30

The virus was stable (did not mutate, antigens stayed the same, same vaccine could be used), the vaccine could be transported without becoming unviable and the symptoms made it easy to identify.