124 - Vaccination Flashcards
What are the absolute contraindications of giving a vaccine?
Confirmed anaphylaxis to previous dose or another component contained in the vaccine.
What relative contraindications to a vaccine are there?
- With a live vaccine: steroid/immunocompromised
- During pregnancy
When could a vaccine be deferred?
NOT for a minor illness without fever
Consider postponing if:
- acutely unwell with fever/systemic upset
- Evolving neurological condition
(to avoid wrongly contributing symptoms)
What common worries are NOT contraindications to vaccine?
Asthma, Eczema, Hay fever (or family history)
Febrile convulsions or epilepsy (or family history)
Previous local adverse reaction
Previous systemic adverse reaction
What is a local adverse reaction?
Few hours after injection
Mild + self limiting
Pain, swelling, redness at site of injection
- should be anticipated
What is a systemic adverse reaction?
Fever, myalgia, malaise, irritability, headache, loss of appetite
Varies on onset - a few days - a week later.
- Not harmful - should be anticipated.
Which vaccines are live attenuated?
MMR BCG Yellow fever rotavirus Influenza (nasal spray) Shingels
Which vaccines are dead / inactivated?
Diphtheria, Tetanus, Polio.. MenC Pneumococcal HPV Influenza (injected) Hep A + B
2 months old. Febrile convulsion previously. Vaccinate?
Yes
Man, heart transplant 2 years ago, on Cyclosporin, Wants yellow fever. Vaccinate?
No. Cyclosporin is immunosupressant, yellow fever live.
Child has accident with Hep B infected needle. Child has runny nose + slight temp. Vaccinate?
Yes - even with fever needs urgent preventative dose.
1 year old, comes for routine vaccinations, is ill - runny nose, conjunctivitis ,cough, fever, small spots on face, blotchy red rash. vaccinate?
Delay - child currently has measles - deal with that first.
Nurse, 8 weeks pregnant, wants BCG. vaccinate?
Delay - always try avoid in pregnancy.
Man needs 2nd Hep A vaccine dose, last time had redness over whole of upper arm. Vaccinate?
Yes - normal to have a reaction - not true anaphylaxis.
Women comes in for MMR. Has asthma treated with inhaled steroids. Vaccinate?
Yes - inhaled steroids aren’t immunosuppressants.
Child recently been having fits, undiagnosed, developmental regression. Comes for normal vaccine schedule. vaccinate?
Delay - until diagnosis found.
What are the 4 main techniques of medical microbiology?
Culture - get sensitivities
Microscopy
Serology (immunological)
Molecular
What is virurlance?
The relative capacity of a microbe to cause disease.
Can be expressed as number of cells necessary
What is pathogenicity?
The ability ti cause damage to a host.
What may a bacteria have to improve its virulance?
Structural:
- Adherence factors
- Motility
Evade host defence
- Antiphagocytic
- Anticomplement
Gene expression:
- Invasion factor
- exotoxin production
- Enzyme production
What are exotoxins?
Produced by gm -ve and +ve bacteria toxins Produced from plasmid DNA High molecular weight polypeptides relatively unstable
What are endotoxins?
Produced by Gm -ve only.
From cell wall - released when wall damaged
More stable
Not as toxic
Cause problems due to immune response activation.
What is LPS?
Lipopolysaccharide - an endotoxin
What are the different ways exotoxins can cause damage?
Cell/tissue degrading enzymes (proteases..)
Toxins that alter cell signalling (cholera, anthrax)
Neurotoxins ( botulism)
Superantigens (staph aureus)
How to exotoxins directly effect a cell?
Membrane acting - interfeer with signal transduction
Membrane disrupting - pore forming, enzymatic toxins
Intracellularly acting - penetrate into cell by injection or AB toxins ‘curl’ in.
Which cells are antigen presenting cells?
Dendritic cells
MAcrophages
B lymphocytes
Where do B cells develop?
Bone marrow - then activated to mature B cell in spleen
Where do T cells develop?
Bone marrow - mature in the Thalmus
What types of T cell develop?
CD4+ T helper cell - activated MHC class II (presents exogenous protein - antigens from bacterial source)
- Th1 -> cellular response
- Th2 -> humoral response
CD8+ Cytoxic T cells - activated by MHC class I (endogenous proteins, from inside a cell) Induce apoptosis of infected cell
How does a T cell mature/be activated?
Must be presented with MHC and Antigen - co-stimulation
How does a B cell get activated?
By an antigen presenting cell
- Th cell - when a B cell matches the antigen it releases IL-4 - stimulates proliferation.
By antigen alone rarely
