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Flashcards in Vaccines: Bacterial & Viral Deck (46)
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1
Q

Name examples of common vaccines

A
Neisseria meningitidis group C, B and A, Y, W
Haemophilus influenzae type b
Streptococcus pneumoniae
Influenza virus 
Tuberculosis (BCG)
Tetanus, Diphtheria, Pertussis 
Measles, Mumps, Rubella
Polio, Hepatitis B,  HPV,  VZV
2
Q

Give examples of travel vaccines

A

Travel vaccines: cholera, travellers diarrhoea, HepA, yellow fever, typhoid

3
Q

What are some common biodefence vaccines?

A

Biodefence: anthrax, plague, tularaemia, smallpox

4
Q

Give examples of agriculture vaccines administered

A

Agriculture: avian flu, foot and mouth virus, rabies

5
Q

When is the Men B vaccine given?

A
  • All newborn babies
  • 2 and 4 months; Booster 12 months
  • Catch up programme for babies born after 1ST May 2015
  • Other groups remain vulnerable – cost effectiveness, shortages of supply, JCVI
6
Q

Describe the structure of the Men B vaccine

A

Bexsero® Components
Outer membrane vesicles (OMV)
- N. meningitidis group B strain Z98/254 menZB
- 3 Surface proteins (non-variant) of the bacteria – recombinant :
• Factor H Binding Protein (fHbp)
• Neisseria Heparin Binding Antigen (NHBA)
• Neisseria Adhesin A (NadA)

7
Q

What are some of the issues surrounding the Men B vaccine?

A
  • more reactogenic;
  • not all serotypes of group B covered (unlike menC)
  • Some cross-protection against menW
  • £75 per dose – needs to be £20 for cost effectiveness.
  • 88% efficacy and strain coverage
  • Duration of protection – 10 years
8
Q

What is meningitis ACWY?

A

Highly virulent invasive strain W

Increasing since 2009

9
Q

Who is vaccinated against Men ACWY?

A

Vaccinate risk groups:

  • 14 – 18 year olds (school year 13) and
  • older university entrants (aged 19 - 25)
  • serotype replacement following menC??
10
Q

Why are live attenuated vaccines only given once?

A

Live attenuated viruses don’t require boosters

11
Q

What is the DTaP vaccine for?

A

DTaP - Diphtheria, Tetanus and Pertussis

- toxoid virus given 3 times

12
Q

What is the IPV vaccine?

A

IPV - inactivated poliovirus

- toxoid virus given 3 times

13
Q

What is the Hib vaccine for?

A

Hib - haemophilus influenzae B vaccine (bacterial infection) also boosted

14
Q

What is Hib?

A

Haemophilus Influenzae Type B
Paediatric disease usually 6 mo - 3 yrs

Incidence: 1/600

15
Q

Describe the signs and symptoms of Haemophilus influenzae B

A

Initially, a nasopharyngitis (often starting with viral infection) spreads to an otitis media, sinusitis, bronchitis, pneumonia or sometimes epiglottitis (requiring a tracheotomy):- croup

16
Q

What other infections are spread from haemophilus Influenzae B ?

A

Spreads :

  • bacteraemia,
  • septic arthritis
  • meningitis (60% cases)
17
Q

What are the consequences of untreated Hib?

A

Neurological disorders (33%) or death (5%) if not vigorously treated

18
Q

How is Hib meningitis and other infections prevented?

A

Vaccine effective: (99% cases are type b)

19
Q

Why are capsulated vaccines not effective in children <2 months

A

Capsules aren’t effective vaccines in children as they can’t make ab against polysaccharides so is conjugated

20
Q

How are capsulated virus made effective for younger babies?

A

conjugated with polysaccharides e.g.

type b - capsule polysaccharide linked to conjugate:-
diphtheria/tetanus toxoids + outer membrane proteins

21
Q

What bacterium causes diphtheria?

A

Corynebacterium diphtheriae

22
Q

Where does the diphtheria localise in the body?

A

Pharynx - non-invasive multiplication

23
Q

Which organs does diphtheria infection effect?

A

Toxin produced locally but acts at a distance

  • Absorbed by lymphatics = systemic effects
  • Damages heart, kidney, nerves, adrenals
  • Kills epithelial cells and polymorphs: gelatinous exudate
  • Ulcer: necrotic exudate: Pseudomembrane
  • Local inflammation ,swelling, lymph nodes - Bull Neck
  • Respiratory obstruction
24
Q

Describe the bacteria causing tetanus

A

Neurotoxin Clostridium tetani

  • Gram +ve rods,
  • terminal drumstick spores
  • anaerobe
  • Soil dweller
25
Q

What is the effect of neurotoxins on the nervous system?

A

Blocks release of inhibitory transmitters GABA and glycine -> unopposed continuous excitation

Neurotoxins cause spastic paralysis causing lock jaw

26
Q

How do vaccines act against neurotoxins?

A

By neutralising toxin we can prevent infection achieved via subunit toxoid vaccine (boosted)

27
Q

Describe the DTaP vaccine

A

Multi-toxin disease

Whole cell vaccine - killed organisms: associated toxicity

28
Q

Describe the new low risk DTa[P vaccine available

A

New low risk acellular vaccine: Adhesin + pertussis toxoids + outer membrane proteins

⇒ Blocks adhesion and neutralises toxin - antibody role, V. effective

29
Q

What are the aims of the influenza programme?

A

To protect those who are most at risk of serious illness or death should they develop influenza
To reduce the circulation of the virus

30
Q

Who is eligible for influenza vaccine?

A
  • all 65 years or over
  • all those aged 6 months+ in a clinical risk group
  • those living in long-stay residential facilities
  • elderly or disabled persons carers
  • household contacts of immunocompromised individuals
  • health and social care workers
  • poultry workers
  • all children 2 – 9 years (most infections and transmission source)
31
Q

How many potential protein targets are there for the influenza vaccine?

A

Require neutralising antibodies targeting the surface proteins
H: hemagglutinin - 15 types
N: neuraminidase - 9 types

32
Q

What are the 2 ways influenza variation can occur

A

Epidemics: Antigenic drift
– mutation + selection

Pandemics: Antigenic shift
– gene reassortment

33
Q

What is the effectiveness of the latest flu vaccine?

A
  • variable by year/age group
  • antigenic drift and shift;
  • prior exposure; cross-reacting antibodies
  • Vaccine production issues
34
Q

Outline the spectrum of pneumococcal infection

A
  • SInusitis (common)
  • Passive pneumococcal disease (bacteramia)
  • Soft tissue infection (rare)
  • Arthritis (rare)
  • Peritonitis (rare)
  • Pneumonia
  • Otitis Media
  • Meningitis
35
Q

Which populations groups are mostly affected by ppneumoccoccal infections?

A

Disease burden mainly in young children (<1) and ageing population 70+
These populations are prone to lobar pneumonia as a result of pneumococcal infection

36
Q

What factors determine who gets a vaccine?

A
  • Community instance rates
  • Age prevalence
  • Surveillance of disease
37
Q

Who is given the polysaccharide pneumonia vaccine?

A
  1. Pneumococcal Polysaccharide Vaccine PPV23
    - 23-valent pneumococcal polysaccharide vaccine (PPV)
    - for at risk adults and children over the age of 2
38
Q

Why are children under 2 not given the polysaccharide pneumonia vaccine?

A

Children under 2 can’t make a long-lasting protective immune response to polysaccharide vaccines

These 23 types of bacteria cause about 96% of all pneumococcal disease cases in the UK

39
Q

How are children under 2 vaccinated against pneumnia?

A
  1. Pneumococcal Conjugate Vaccine PCV-13V
    - Polysaccharides from 13 most common capsule types
    - Conjugated to T/D toxoids + OMP as for Hib and MenC
40
Q

How many types of HPV are there?

A

Over 40 types

41
Q

What are the different types of Genital warts (HPV)?

A

High risk types (16,18) – lead to cancer

  • HPV16: 50%
  • HPV18: 20%

Low risk types (6,11) - warts

42
Q

What are the 2 HPV licensed vaccines?

A

Gardasil: protects against HPV 6,11,16,18 - used now

Cervarix: protects against HPV 16,18

43
Q

What vaccines are commonly in vaccines?

A

Neonatal tetanus: Disease of 8th Day - 360,000 deaths/yr

Tetanus toxoid to mother in late pregnancy→ high titres of maternal IgG in neonate

44
Q

Why are live attenuated vaccines not given during pregnancy?

A

Don’t want live vaccines during pregnancy: ?damage to foetus e.g. rubella (MMR)

45
Q

What prophylactic vaccines are given during pregnancy?

A
  1. TdaP/polio - whooping cough - Boostrix IPV

2. Flu - mother and baby protection – earlier the better

46
Q

Who is given a TB vaccine?

A

All infants living in areas where TB incidence is >40/100,000

All infants with a (grand)parent born in a country where TB incidence is >40/100,000

at risk secondary school children

Previously unvaccinated new immigrants from high prevalence countries for TB