Vaccination Flashcards
What’s passive immunity. What are the 2 types
Ready made antibodies or antitoxins are given to an individual
Natural - when a baby becomes immune due to antibodies from its mother
Artificial - when you become immune after being injected with antibodies from someone else
What’s active immunity. What are the 2 types
Your body has an immune response and produces antibodies
Natural - when you become immune after catching a disease
Artificial- when you become immune after you’ve been given a vaccination containing a harmless dose of antigen
What is a vaccine
A weakened or alternated form of the antigen
What do vaccines do
Memory cells are produced. They remain in the blood for a greater faster response to future infection with the pathogen. Resulting in rapid production of antibodies and the new infection is rapidly overcome before it causes any harm or any symptoms
What does the success of a vaccination programme depend on
Must be economically available in sufficient quantities
Must be few side effects or none
Storing, producing and transporting must be available
Being able to administrate the vaccine properly
Must be possible to vaccinate the vast majority of the vulnerable population to produce herd immunity
What is herd immunity
When a sufficiently large proportion of the population has been vaccinated to make it difficult for a pathogen to spread within that population
Therefore where the vast majority are immune it is high improbable that a susceptible invidious will come in contact with an infected person
Why vaccination may not eliminate disease
Fails to induce immunity in certain individuals (e.g. detective immune Systems )
May develop disease immediately after vaccination but before there immunity levels are high enough to prevent it
Pathogen may mutate frequently, do that it’s antigens change suddenly rather then gradually - therefore vaccines become ineffective as new antigens on the pathogen are no longer recognised by the immune system
May be lots of varieties of a particular pathogen - hard to develop a vaccine against them all
Certain pathogens hide from the body’s immune system - by concealing themselves inside cells or by living in places out of reach like intestines
May have objections to vaccination for religious, ethical or medical reasons.
What ethical questions do vaccines raise
Involves use or animals
May have side effects
Trial vaccine where disease is common
All should be vaccinated . Should be compulsory?
Expensive
Health risks from vaccination
Explain why vaccinating against influenza is no always effective
It displays antigen variability. It’s antigens change frequently and so antibodies no longer recognise the virus. New vaccines are required to simulate the antibodies that complement the new antigens
