Flashcards in 5.4 Antibodies & Vaccination Deck (17):
There is a small time delay between getting infected with a pathogen and the production of antibodies against that pathogen called...
Time delay is because...
It takes time for the antigen to be recognised and for specific plasma cells to be produced (once clone of plasma cells had been made, antibodies produced in large amounts)
Primary response is...
The first time that the body has encountered this particular antigen
Once pathogen has been destroyed...
Number of specific plasma cells goes down and the number of specific antibodies in the blood falls
Memory B cells remain
In the Secondary response...
The person has been infected with the same pathogen memory B cells become activated rapidly and produce large amounts of antibodies very quickly - usually destroy the pathogen before the person is aware of any symptoms of illness
Artificial immunity is...
When a person is vaccinated against a disease
A vaccination is when...
A person is given antigens, either by injection or by mouth - produces a primary response
As a result of a vaccination...
The body produces memory B cells against the specific antigens
- if the person is infected by the real pathogen the memory B cells will produce large numbers of antibodies in a secondary response (stopping the person from becoming ill)
Different forms of vaccination are...
1) Dead microorganisms - the pathogen is killed (heat/chemicals) but the antigens remain on its surface, so the immune system responds to the pathogens, without it causing any damage
2) Attenuated microorganisms - some strains of a pathogen stimulate the immune system, but they didn't actually cause the disease because they've been weakened (repeatedly sub cultured) in the lab
3) Isolated antigens - sometimes the antigen can be separated from the pathogen and injected to trigger an immune response
Active immunity is when...
The body produces its own memory cells - either by catching a disease or as a result of vaccination
Passive immunity is when...
A person is given ready-made antibiotics
Example of passive natural is...
Antibodies passed from mother to foetus via placenta
Antibodies passed from mother to baby in breast milk
Example of active natural is...
Antibodies produced by plasma cells due to infection by a pathogen
Example of artificial passive is...
Antibodies produced by another organism are injected into a person
Example of artificial active is...
Antibodies produced by plasma cells as a result of antigens being introduced to the body by vaccination - memory B cells
Successful vaccine is (e.g. Smallpox)...
-Stable pathogen (no mutation, 1 type of antigen)
-Live vaccine - 100% effective
-Easy to produce, cheap, high availability
-Easy storage (freeze-dried, heat stable)
-Infected people easy to identify
-Easy to administer (reusable needle, no booster needed; 1 inoculation)
-Only human host (no other reservoir of infection)
-Volunteers/spotters used to find new cases