20. Vaccination Flashcards
When are booster injections needed?
Targeted vaccines are for particular groups. Give examples.
What are some contra-indications for immunisation?
If vaccine live e.g. MMR, tend only to need 1 or 2 injecitons; when vaccine dead e.g. diptheria, pertussis, need a few (boosters).
MMR - neonatal depending on risk area/family. Hep B - in 1st yr if born to affected mum. Influenza/pertussis - pregnant women.
Anaphylaxis to previous dose, immunosupression, acutely unwell (postpone). Pregnancy in some cases.
What is the ‘rule of the thumb’ of the % of population to vaccinate to give herd immunity?
Why might some parents choose not to vaccinate their children?
What are the features of an effective vaccine?
85%
Side effect fear, think that if everyone else around them has been vaccinated their child will be ok etc.
Safety, protection, longevity, neutralising Abs (must be induced to protect against pathogens such as polio), protective T-cells (must be induced to protect against pathogens such as TB), practicality (cheap and easy to administer).
What are some considerations for vaccine design?
What are the 2 main things to test for a vaccine?
What is the difference between vaccination and immunisation?
Live attenuated or inactivated, or protein? Plus adjuvant - if so, which one? Which administration route (mucosal/injection)? Are boosters needed? Safety and cost? Modern vaccines = recombinant protein/DNA vaccine/theraputic vaccine
Reactions to administration (anaphylactic, fever, local reactions, reversion of live vaccines to wild type), problems when pathogen encountered (vaccine ineffective, heightened immune response to illness).
Vaccination: process of injecting something into body that improves quality of immune system. Irreversibly changes immune system.
Immunisation: protecting you from pathogen but only temporarily, receive Abs but it won’t change the immune system.
What is passive immunisation? What problems may arise?
What are the 2 different types of polio vaccine, and which ones are used for what situations?
Serum (including Abs against a pathogen) transferred to non-immune individual. Also mum -> baby via placenta. Often given to counteract insect/animal venoms. Usually horse serum used. Problem: immunisation lasts as long as Ab active (few months), and pt makes immune response against serum (serum sickness).
1) Inactivated (injected): virus can’t replicate, good humoral immunity generated, no chance of disease but may be SEs, can pass polio on.
2) Attenuated (oral): virus can replicate but doesn’t cause disease, humoral and cell-mediated immunity, occasional polio in pts.
If country has lots of polio = use quick safe cheap vaccine = stops people dying but doesn’t stop it spreading. Once numbers are down switch to oral = stops spreading. Then once got rid of polio switch back to vaccine to keep everyone safe.
List some inactivated and attenuated vaccines.
How are tetanus-prone wounds managed?
What is the duration of protection of the Hep B vaccine?
Describe haemophilus influenzae type B.
Inactivated: DPT (diptheria (eliminated from UK), pertussis, tetanus), polio, cholera, influenza, plague.
Attenuated: MMR, polio (oral), chicken pox, BCG, influenza, yellow fever, rabies.
If fully immunised give booster, if >10 yrs since last dose, give tetanus Ig and vaccine.
At least 3-5 years. 90% effective after a 3-dose series, but this decreases after 40 yrs old.
Encapsulated G-ve bacterium, main cause of bacterial meningitis and epiglotitis in infants.
How does a recombinant peptide vaccine work?
How do DNA vaccines work?
Doesn’t use whole pathogen (reduces risk of SEs). Specific gene removed from virus, added to yeast culture, single purified viral protein used for vaccine and mixed with adjuvant (to convince body it’s fighting infection by activating dendritic cells etc.)
Specific gene isolated from pathogen, placed in bacterial plasmid vector, bacterial DNA acts as adjuvant, plasma injected into muscle of recipiant = viral challenge and animal protected.
Future = theraputic vaccines? Sick animal vaccinated to boost immune response and clear it’s infection.
