5.6: Vaccination

Question 1

What is immunity

Answer 1

The ability to resist infection

Question 2

What are the two forms of immunity

Answer 2

Passive immunity

Active immunity

Question 3

What is passive immunity

Answer 3

Passive immunity is produced by the introduction of antibodies into individuals from an outside source.

Antibodies aren’t produced and break down, no memory cells are produced therefore these is NO long-term immunity

This is common with Antivenoms

Question 4

What is active immunity

Answer 4

Active immunity is produced by stimulating the production of antibodies by the individuals own immune system

Direct contact with the pathogen is necessary

(2 Types)

Question 5

What are the two types of active immunity

Answer 5

Natural active immunity

Artificial active immunity

Question 6

What is natural active immunity

Answer 6

Natural active immunity results in an individual becoming infected with a disease under normal conditions.

The body produces its own antibodies

Question 7

What is artificial active immunity

Answer 7

Artificial active immunity forms the basis of immunisation. It involves inducing an immune response (vaccination)

Question 8

What is a vaccination

Answer 8

The introduction of the appropriate disease antigens into the body, by injection or mouth

Question 9

What is the intention of vaccination

Answer 9

The intention is to stimulate an immune response

Question 10

How does a vaccination work

Answer 10

It activates the cellular response and the humoural response

The most important feature is the production of memory cells

Memory cells remain in the blood and allow a more immediate response

Question 11

Features of a successful vaccination programme

Answer 11

1. Must be economically available for use in sufficient quantities to immunise a population
2. Few side-effects, this may deter a population from becoming vaccinated
3. Means of producing, storing and transporting the vaccine
4. Means of administering the vaccine
5. Be able to vaccinate the majority of a population to produce Herd Immunity

Question 12

What is Herd Immunity

Answer 12

Herd Immunity arises when a sufficiently large proportion of the population has been vaccinated to make it difficult for a pathogen to spread

Question 13

What is the concept behind Herd Immunity

Answer 13

The concept is based on the idea that pathogens are passed form individual to individual in close contact

When the majority of a population is immune, it is highly improbable that a susceptible individual will come in contract with an infected person

Question 14

Why is Herd Immunity important

Answer 14

It means those that are not immunised will be protected nonetheless. This is because the pathogen cannot spread throughout a population

Question 15

Importance of herd immunity within a population

Answer 15

It isn’t possible to vaccine everyone in a population.

For example, Babies and Very young children who do not have a strong enough immune system.

Question 16

Why might a vaccination programme not elimate a disease

Answer 16

1. The vaccination may fail to induce immunity in certain individuals, e.g. People with defective immune systems
2. Individuals may develop the disease before they get a high enough level of immunity to prevent it
3. Pathogen may mutate frequently and change its antigens suddenly (Antigenic Variability)
4. Certain pathogens hide from the bodys immune system

Question 17

Ethics of using vaccines

Answer 17

• Use of Animals
• Long term side effects
• Testing of vaccines with unknown side-effects can occur in countries with a high infection rate
• Expensive to develop vaccines, vaccines continue to be developed even when the majority of a population is immunised - money could be used elsewhere