Lecture 27 - Immunisation

Question 1

Benefits of immunisation?

Answer 1

immunity to infection, reduced disease in ALL people due to reduced transmission (herd immunity)

Question 2

How we get protected?

Answer 2

protein antigens (T-cell-dependent antibodies), polysaccharide antigens (T cell-independent antibodies) live viral (antibodies, CD8 cytotoxic)

Question 3

Classifications of vaccines?

Answer 3

live attenuated vaccines, inactivated vaccines (whole, fraction, toxoid, polysaccharide based, conjugate poysaccharide)

Question 4

Live vaccine?

Answer 4

modify virus or bacteria in lab, replicate and produce immunity but not illness, lifelong immunity - can cause problems in immunocompromised people

Question 5

Live vaccine e.g.?

Answer 5

viral: measles, rubella, oral polio, bacterial: BCG, oral typhoid, reassorted: rotavirus

Question 6

Inactivated vaccines & whole e.g.?

Answer 6

repeated dose required; whole viral: influenza, polio, rabies and Hep A; whole bacterial: pertussis, typhoid, cholera

Question 7

Fractional (component) vaccines?

Answer 7

subunits (hep B, influenza, acellular pertussis), toxoids (tetanus); requires multiple dosing but less antigen infection is preferred

Question 8

Childhood vaccines - first?

Answer 8

Infanrix hexa - diphtheria, tetanus, acellular pertussis, inactivated polio, Haemophilus influenzae type B, hepatitus B; componenet antigens, 4x

Question 9

Childhood vaccines - second?

Answer 9

MMR, all live, given @ 15 months and 4 years

Question 10

Tetanus?

Answer 10

penicillin sensitive, gram positive, easily introduced to deep dirty injuries, 10 days after exposure demonstrates muscular rigidity, arched back, lock jaw (tetanospasm toxin)

Question 11

Tetanus epidemiology?

Answer 11

elderly affected by declined immunity, neonatal tetanus high in developing world - passed from mother that has no access to immunisation (plan to give immunisations to all women of child-bearing age in high risk areas)

Question 12

Passive immunisation - advantages?

Answer 12

immediate protection

Question 13

Passive immunisation - disadvantages?

Answer 13

not long term, transmission risk of other disease from donor, expensive and not always readily available, expensive and not always available, serum sickness

Question 14

Pertussis/whooping cough - catarrhal phase?

Answer 14

1-2 weeks, runny nose, conjunctival infection, malaise

Question 15

Pertussis/whooping cough - paroxysmal phase?

Answer 15

1-10 weeks, short expiratory burst of rapid coughs, inspiratory gasp and high pitched whoop (followed by convalescent/recovery phase of weeks/months)

Question 16

Pertussis complications?

Answer 16

secondary bacterial infections (pneumonia), encephalopathy, seizures, apnoea

Question 17

Pertussis and antibiotics?

Answer 17

may shorten illness if given early and decrease infectivity but typically do little

Question 18

Non-infants recommended for pertussis vaccination?

Answer 18

11-12yr booster, adults living with young children, adults working with children, health care workers (particularly of newborns)

Question 19

Polio vaccines in NZ?

Answer 19

Injected killed version introduced 1956, oral vaccine introduced to completely lower cases (intestinal immunity), injected reintroduced post-2000