Principls of Immunisation

Question 1

what are the 3 aims of immunisation?

Answer 1

prevent onset of disease (primary prevention)
interrupt transmission
Alter course of infection/disease to prevent or limit consequences (secondary prevention)

Question 2

which type of disease does immunisation control?

Answer 2

communicable diseases

Question 3

what do vaccines do?

Answer 3

teach the immune system to recognise bacteria and viruses before the individual encounters them as potential pathogens so allowing the body to fight against the pathogen

Question 4

name 3 immunological mechanisms

Answer 4

active immunity
passive immunity
herd immunity

Question 5

what are antigens usually made of?

Answer 5

proteins or polysaccharides (sugars)

Question 6

what are antibodies made of?

Answer 6

proteins

very specific to individual antigens

Question 7

how are B cells produced?

Answer 7

humoral immune system

• mature in the bone marrow
• triggered to produce antibody when they encounter foreign antigen

Question 8

how are T cells produced?

Answer 8

cell-mediated immune system

• mature in Thymus
• CD4 and CD8 cells
• orchestrate response of immune system by binding to other cells and sending out signals

Question 9

what is passive immunity?

Answer 9

transfer of pre-formed antibodies (immunoglobulins)

Question 10

through what 2 methods can passive immunity be acquired?

Answer 10

mother to unborn baby via placenta
- lasts up to 1 year
- doesn't protect against all antigens
from another person or animal
- antibodies from blood donors
- human normal Ig
- specific Ig

Question 11

what 2 components of the immune system are present in passive immunity and what do they protect against>

Answer 11

human immunoglobulin
- hep B, rabies, varicella zoster etc
anti-toxin
- diphtheria, botulinum etc

Question 12

what are the advantages of passive immunity?

Answer 12

rapid action
post-exposure
can attenuate illness
outbreak control
can be used if live vaccine is contraindicated

Question 13

what are the disadvantages of passive immunity?

Answer 13

short term protection
short time window
blood derived
hypersensitivity reactions
expensive

Question 14

natural vs artificial passive immunity?

Answer 14

natural = transplacental transfer
artificial = human IgG

Question 15

natural vs artificial active immunity?

Answer 15

natural = natural infection
artificial = artificial immunisation

Question 16

mechanism of vaccines?

Answer 16

induce cell mediated immunity responses and serum antibodies

different vaccines induce different speed and sustainability of response

Question 17

what are live vaccines?

Answer 17

attenuated organism, replicates in host

• OPV
• MMR
• varicella
• rotavirus
• flu

Question 18

what are inactivated vaccines?

Answer 18

suspensions of killed organism
- pertussis (whooping cough)
- typhoid
OR
subunit vaccines
- toxoids (e.g diphtheria, tetanus, pertussis)
- polysaccharides (e.g pneumococcal, typhoid)
OR
conjugate vaccines
- polysaccharide attached to immunogenic proteins
- Hib, MenC

Question 19

what are 5 contraindications to vaccines?

Answer 19

confirmed anaphylaxis to previous dose of same vaccine
immunosuppression or pregnancy (if live vaccine)
egg allergy
severe latex allergy
acute or evolving illness (wait until resolved)

Question 20

what is herd immunity?

Answer 20

unvaccinated individuals are protected through having sufficiently large population of population vaccinated

Question 21

what is the proportion of the population required to be immune based on?

Answer 21

transmissibility and infectiousness of organism

social mixing in population

Question 22

give 3 examples of herd immunity?

Answer 22

measles = 90%
umps = 75-86%
smallpox = 80-85%
requires that there is no reservoir of infection

Question 23

what is the Scottish immunisation programme?

Answer 23

programme of vaccination

Question 24

what is the purpose of the vaccine schedule in the UK?

Answer 24

to provide early protection against infections that are most dangerous for the very young (whooping cough, meningococcal, pneumococcal)
to ensure continued protection by providing subsequent immunisations and booster doses before reaching age when risk increases

Question 25

how is the age at which vaccine is offered based on?

Answer 25

risk of disease level of protection risk of complications

Question 26

are vaccines still given, even if older than recommended age?

Answer 26

yes

Question 27

if a course of immunisation is interrupted, does it need to be restarted?

Answer 27

no | can usually be resumed and completed due to immunological memory

Question 28

name 11 routine childhood vaccines

Answer 28

``` hexavalent meningococcal group B rotavirus pneumococcal Hib/meningococcal group C MMR influenza diphtheria, tetanus, pertussis and polio tetanus, diphtheria and polio booster meningococcal groups A, C, W and Y HPV ```

Question 29

what selective childhood vaccines are given for at risk children?

Answer 29

flu pneumococcal polysaccharide vaccine BCG Hep B

Question 30

name 4 adult programmes of vaccination

Answer 30

pneumococcal polysaccharide vaccine shingles (70 y/o) seasonal flu various selective programmes

Question 31

when and how must public health be notified of a disease?

Answer 31

clinical suspicion of specific disease or health risk state - notification in writing within 3 days - notification by phone ASAP if urgent

Question 32

what characterises diphtheria?

Answer 32

URTI sore throat low grade fever white adherent membrane on tonsils, pharynx and/or nasal cavity

Question 33

what causes diphtheria?

Answer 33

aerobic gram-positive bacterium | corynebacterium diptheriae

Question 34

what causes meningococcal disease?

Answer 34

invasive infection due to Neisseria meningitidis

Question 35

how serious is meningococcal disease?

Answer 35

10-20% mortality in children

Question 36

which types of meningococcal disease can be vaccinated against>

Answer 36

groups: - A - C - W - Y135 - B

Question 37

how does meningococcal disease spread?

Answer 37

person-person contact through respiratory droplets incubation = 3-5 days colonisation of nasopharynx

Question 38

what are the 3 phases of vaccine trials?

Answer 38

phase 1 = is it safe, is it immunogenic phase 2 = how reactogenic is it, what dose, how does it compare with current vaccines phase 3 = is it efficacious, are there any rarer reactions/safety issues?