Immunisation

Question 1

Vaccination is considered the single most effective medical intervention so far second only to what?

Answer 1

Access to clean water

Question 2

There are 3 strategies of vaccination what are they?

Answer 2

1) Selective protection of the vulnerable
2) Elimination - herd immunity
3) Eradication

Question 3

What are the 5 possible programmatic aims of vaccination programmes?

Answer 3

1) Prevent deaths
2) Prevent infection
3) Prevent transmission (secondary cases)
4) Prevent clinical cases
5) Prevent cases in certain age groups

Question 4

What is the single largest aim of vaccination programmes?

Answer 4

To reduce mortality and morbidity from vaccine preventable infections

Question 5

What is meant by passive immunity?

Answer 5

Either vertical transmission of auto-Ab from mother to foetus & breastfeeding
Or injection of human immunoglobulin

Question 6

What is meant by active immunity?

Answer 6

Immunity arising from natural infection, or injection of inactivated or attenuated live organisms

Question 7

What is meant by immunologic memory?

Answer 7

The persistence of protection for many years after natural infection or vaccination

Question 8

Name the 4 different types of antibody?

Answer 8

IgM, IgG, IgA, IgE

Question 9

What is the difference between primary immune response and secondary immune response and which Ab are involved?

Answer 9

Primary immune response develops in the weeks following first exposure to an Ag - mainly IgM antibody
Secondary immune response occurs on re-exposure and is faster and more powerful
Mainly IgG Ab

Question 10

How basically do antibodies produce immunity?

Answer 10

1) Ab produced from B lymphocytes
2) Ag binds non-specifically to variable region of Ab (Ig) molecule, this triggers clonal expansion
3) 1st wave of IgM production, followed by IgG production
4) IgG bonds tightly to Ag and through simultaneous complement binding facilitates the destruction of the Ag bearing micro-organism
5) When infection resolved levels of IgG decline
6) However one set of the IgG producing B lymphocytes persists with the ability to recognise that specific Ag = immunological memory

Question 11

Give 4 different vaccination programmes which use live organisms?

Answer 11

1) MMR
2) BCG
3) Yellow fever
4) Varicella

Question 12

Give 3 different vaccination programmes which use inactivated organisms?

Answer 12

1) Pertussis
2) Typhoid
3) IPV

Question 13

Give 2 different vaccination programmes which use components of organisms?

Answer 13

1) Influenza

2) Pneumococcal

Question 14

Give 2 different vaccination programmes which use inactivated toxins?

Answer 14

1) Diphtheria

2) Tetanus

Question 15

In what disease is human immunoglobulin from pooled plasma sometimes injected as prophylaxis?

Answer 15

Measles - HNIG

Question 16

In what diseases can specific human immunoglobulin be injected as prophylaxis? 5

Answer 16

1) Tetanus
2) Botulism
3) Hep B
4) Rabies
5) Varicella

Question 17

What are the 3 advantages of live vaccines?

Answer 17

1) Single dose often sufficient to induce long-lasting immunity
2) Strong immune response evoked
3) Local and systemic immunity produced

Question 18

What are the 5 disadvantages of live vaccines?

Answer 18

1) Potential to revert to virulence
2) Contraindicated in immune-suppressed patients
3) Interference by viruses or vaccines and passive antibody
4) Poor stability
5) Potential for contamination

Question 19

What are the 3 advantages of inactivated/killed vaccines?

Answer 19

1) Stable
2) Constituents clearly defined
3) Unable to cause the infection

Question 20

What are the 4 disadvantages of inactivated/killed vaccines?

Answer 20

1) Need several doses
2) Local reactions common
3) Adjuvant needed: keeps vaccine at injection site, activates APCs
4) Shorter lasting immunity