Theme 3 Lecture 22: Immunisation

Question 1

What are the two most effective medical interventions ever?

Answer 1

1. access to clean water

2. vaccination

Question 2

Which infectious disease is responsible for the largest number of child deaths by infection?

Answer 2

pneumococcal infection

Question 3

What are the aims of vaccination?

Answer 3

• selective protection of the vulnerabke
• elimination - herd immunity (to create the level of immunity to be high enough so propagation will not occur)
• eradication
• prevent deaths, infection, transmission
• to reduce mortality and morbidity from vaccine preventable infections

Question 4

What are our non-specific immune defences?

Answer 4

• unbroken skin
• mucous membrane of gut, lung
• acid and enzymes of gut
• non-specific metabolism/inactivation

Question 5

What is passive immunity?

Answer 5

vertical transmission of auto-antibodies from mother to foetus and breastfeeding

• maternal antibodies can protect the baby for up to a year against illness to which the mother is immune
• Ig can be given to a person who needs antibodies
• usually lasts weeks/months

Question 6

What is active immunity?

Answer 6

• long-lasting immunity produced by the immune system in response to antigens
• from natural infection or vaccination

Question 7

What is immunologic memory?

Answer 7

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

Question 8

Primary immune response develops in the weeks following first exposure to an antigen. Which antibody is mainly responsible for this?

Answer 8

IgM

Question 9

Which antibody is mainly responsible for the faster, more powerful secondary immune response?

Answer 9

IgG

Question 10

How do antibodies produce immunity?

Answer 10

• Antibodies produced from B lymphocytes
• Antibody binds non-specifically to variable region of antibody (Ig) molecule. This triggers clonal expansion
• 1st wave of IgM production, followed by IgG production
• IgG binds tightly to antigen and through simultaneous complement binding facilitates the destruction of the antigen-bearing micro-organism
• When infection resolved levels of IgG decline
• However one set of the IgG producing B lymphocytes persist with the ability to recognise that specific antigen = immunological memory

Question 11

Which main vaccines are live and act like the natural infection?

Answer 11

MMR
BCG (Tb vaccine)
Yellow fever
Varicella

Question 12

Which main vaccines are inactivated?

Answer 12

pertussis, typhoid, IPV

Question 13

What does the IPV vaccine protect against?

Answer 13

diphtheria, tetanus, pertussis (whooping cough) and polio

Question 14

Which vaccines use components of the antimicrobial organisms?

Answer 14

influenza, pneumococcal

Question 15

Which vaccines use the inactivated toxins?

Answer 15

diptheria, tetanus

Question 16

How do passive immunity vaccinations work and which vaccines work by developing passive immunity?

Answer 16

• infection of human immunoglobulin

- tetanus, botulism, hepB, rabies, varicella

Question 17

What are the advantages of live vaccines?

Answer 17

• single dose often sufficient to induce long-lasting immunity
• strong immune response evoked
• local and systemic immunity produced

Question 18

What are the disadvantages of live vaccines?

Answer 18

• potential to revert to virulence
• contraindicated in immunosuppressed patients
• interference by viruses or vaccines and passive antibody
• poor stability
• potential for contamination

Question 19

What are the advantages of inactivated vaccines?

Answer 19

• stable
• constituents clearly defined
• unable to cause the infection

Question 20

What are the disadvantages of inactivated vaccines?

Answer 20

• need several doses
• local reactions common
• adjuvant needed
• shorter lasting immunity

Question 21

What are the newest vaccines that have been developed?

Answer 21

varicella 
menveo
menB
rotavirus
fluenz