Immunisation

Question 1

What is passive immunity?

Answer 1

Transfer of preformed antibodies, tends to be short-lived.

Question 2

What is active immunity?

Answer 2

A persons own immune system creates antibodies. It is stronger and longer lasting.

Question 3

Examples of passive immunity:

Answer 3

IgG antibodies passed across the placenta from mother to baby.
Infusion of antibodies against certain diseases eg. rabies, measles and varicella zoster. Given when an individual has been exposed and needs urgent protection.

Question 4

What type of vaccine: A live pathogen which has been altered to become harmless

Answer 4

Live attenuated

Question 5

2 pros of live attenuated vaccines (BCG, MMR, yellow fever)

Answer 5

1. Give a very good immune response

2. Closely resemble the natural infection

Question 6

Disadvantages of live attenuated vaccine:

Answer 6

1. vaccine can mutate in those who are immunocompromised, and revert to a disease causing strain
2. vaccine can be shed in the faeces of the individual - do not give if household contacts are immunocompromised
3. sustained vaccine strain infection (virus can replicate in a lymph node)

Question 7

Who should not get a live attenuated vaccine?

Answer 7

1. Immunocompromised patients

2. Pregnant women - risk of the virus crossing placenta

Question 8

The pathogen is killed by chemical or physical processes and then injected (polio)

Answer 8

Inactivated whole cell vaccine

Question 9

Advantage and disadvantage of inactivated whole cell vaccines

Answer 9

Can be given to immunocompromised (Good)

Gives a weaker immune response than live attenuated (bad)

Question 10

An inactivated toxin vaccine has had its toxin chemically treated so that it is no longer harmful but still causes an immune response. Examples of this vaccine are?

Answer 10

Diptheria and tetanus

Question 11

A subunit vaccine is:

Answer 11

A small part of the pathogen is injected. Cannot cause disease. Often produced in a yeast or insect vector. Examples include; HPV Hepatitis, pertussis or influenza.

Question 12

What are polysaccharide vaccinations? (meningococcal and pneumococcal vaccines)

Answer 12

Polysaccharides are long repeating chains found on the surface of bacteria. This vaccine causes a T cell independent response, as only B cells are involved. Poorly immunogenic, so not used in children.

Question 13

What is a conjugated polysaccharide vaccine?

Answer 13

A purified bacterial polysaccharide is linked to a protein eg. diphtheria toxoid. Due to the protein there is a T cell dependant response and a production of B memory cells.

Question 14

What is an adjuvant?

Answer 14

Substances that stimulate a stronger immune response that lasts longer. Examples include; aluminium phosphate hydroxide.

Question 15

At what age should a person get a varicella zoster vaccine?

Answer 15

75 years

Question 16

What 2 vaccines should you have at 65?

Answer 16

Pneumoncoccal and annual flu vaccine

Question 17

Why are pregnant women vaccinated against whooping cough?

Answer 17

To protect the baby, as whooping cough can be fatal in babies. They get passive immunity from mum after vaccination, which protects them until they are old enough to be vaccinated themselves

Question 18

Vaccine adverse affects;

Answer 18

Pain, swelling and redness at injection site. Systemically unwell with fever and headache. Can be associated with a temporary rash. Anaphylaxis is rare.

Question 19

Why should a vaccine not be given to someone with an intercurrent illness?

Answer 19

Giving a vaccine when someone already has a febrile illness will not make the person worse, or have less chance of it working. It is not given as likely any worsening of the persons symptoms will be blamed on the vaccine unfairly.

Question 20

Which is more common, primary or secondary vaccine failure?

Answer 20

Secondary. This is when a person gets immunity after vaccination but it wanes with time. This can be a normal physiological occurrence.
Primary failure is when there is no immune response at all.