Lecture 29 Flashcards
What is the difference between vaccination and variolation?
Variolation involves giving a small dose of the actual virus
Vaccination is use of a related but less dangerous virus
What are the 5 types of Vaccines?
Whole live organism vaccine Whole Killed organism vaccine Components of organism Polysaccharide Vaccines Conjugate Vaccines
What are the features of whole live organism vaccines?
Establish an infection in vaccinated person
Immune responses clear infection in 1-2 weeks
There is prolonged exposure of the host to the microorganism
A single dose is usually effective at stimulating lifelong immunity
What are the features of whole killed organism/ components of organism vaccines?
Only briefly expose host to the antigens of organism
Immune response clears within a few days
typically three or more doses are required to stimulate good immunity
Often used in immunocompromised patients as it is a less dangerous vaccine
What is the problem with polysaccharide vaccines and how was this overcome?
There are only weak immune responses to polysaccharides with little immunological memory leading to the development of conjugate vaccines where the polysaccharide is attached to a carrier protein
This results in the conjugate being taken up by B cells with the protein being digested and presented allowing T cell conversion and good immunological memory
What are routine component vaccines given in NZ?
Dipatheria, tetanus, acellular pertussis, Haemophilus influenzae type B, Hepatits B
( D T aP HiB HepB)
These are given at 6 weeks, 3 months, 5 months, 15 months
What is the live vaccine routinely given to children in NZ?
MMR
Given at 15months, and 4 years
How effective are vaccines at preventing disease?
Most are extremely effective with efficacy often above 90%
What is Pertussis?
Childhood illness with paroxysms of coughing with whoop, apnoea and vomiting
What is herd immmunity?
The concept that if enough people are immunised then the disease will not be able to spread therefore proteting the few forr whom the vaccine did not work or who did not recieve the vaccine
