3.2.4.6 - Vaccination

Question 1

what does a vaccine contain?

Answer 1

dead/weakened pathogen

Question 2

How does a vaccine lead to the production of antibodies?

Answer 2

1. vaccine contains antigens from pathogen
2. macrophage presents it on its surface
3. T cell with complementary receptor binds
4. activates T helper cells
5. which activate specific B cells
6. B cells selected, divide mitosis
7. B cell divides into plasma cells producing antibodies

Question 3

difference between passive and active immunity

Answer 3

1. active involves memory cells (passive doesn’t)
2. active produces antibodies from plasma cells
3. passive antibodies come from another source (breast milk)
4. Active provides long term immunity
5. Passive short term immunity - antibodies don’t last forever
6. Active slower acting, passive fast acting

Question 4

does a vaccination lead to active or passive immunity?

Answer 4

Active, as it leads to antibody production.

Question 5

does a vaccination lead to artificial or natural active immunity?

Answer 5

artificial

Question 6

what differs between the antibody production during a vaccination / primary infection, and secondary infection?

Answer 6

on secondary infection there are more antibodies produced, the production is more rapid, and they remain in the blood for longer.

Question 7

is a vaccination a preventative measure or a cure for a contagious disease?

Answer 7

preventative, if someone already has the disease a vaccine is useless.

Question 8

what are the features of a successful vaccination program?

Answer 8

• must be economically viable to make the vaccine on a large scale.
• there must be few side effects as uptake will fall.
• must be easy to produce, store and transport (this may require refrigerated vehicles).
• must be easily administered by trained staff
• must be able to vaccinate a large proportion of the population.

Question 9

What is meant by the term ‘herd immunity’?

Answer 9

When a large proportion of the population have been vaccinated and are as a result immune to a disease. This means that those who are unvaccinated or susceptible to the disease are less likely to be in contact with each other so it is unlikely that the disease will spread.

Question 10

Which members of a population are expected to be most susceptible to disease?

Answer 10

• babies and very young children who have not yet been vaccinated.
• those with compromised immune systems

Question 11

Why does vaccination rarely eradicate diseases?

Answer 11

• immunity is not induced in those with defective immune systems.
• it is still possible to catch the disease immediately after vaccination as immunity has not yet been achieved.
• Pathogens may mutate so antigens change (e.g. antigenic variability in the influenza virus).
• there may be many strains of a particular disease (e.g. the common cold).
• some pathogens hide from the immune system (e.g. cholera).
• People refuse to get themselves and their children vaccinated.

Question 12

What sort of pathogen hides from the immune system in the intestine?

Answer 12

Cholera

Question 13

Why might some people have ethical objections to vaccination programs?

Answer 13

• they are tested on animals
• they may have side effects
• can individuals be forced to get vaccinated in the interest of public health?
• is it acceptable to trial a new vaccine in a country where the disease is the most common?
• is it right to make vaccination compulsory regardless of personal belief?
• should we continue to use expensive vaccines if the cases of a disease are very low or kill very few?

Question 14

What diseases are vaccinated against in the MMR vaccine?

Answer 14

Measles, mumps, rubella

Question 15

Which disease made a come back when MMR uptake fell in certain areas due to an unfounded link to autism?

Answer 15

Measles