Immunisation 3.7 Flashcards
What is immunisation
The process by which a person develops immunity to a disease causing organism
How can immunity be developed
By vaccinations using antigens from an infectious pathogen, so creating memory cells
What are infectious pathogens mixed with
An adjuvant
What is an adjuvant
Mixed with a pathogen/antigen to make the vaccine more effective, so enhancing the immune response
What are the 4 types of antigens used in a vaccine
Weakened pathogen
Dead pathogen
Part of a pathogen
Inactivated toxin
What is herd immunity
When a large percentage of the population are immunised which helps reduce the spread of diseases
How are non immune individuals still protected
There is a less chance they will come into contact with an infected individual
When is the only time that herd immunity is achieved
When a threshold of immunised people os reached
What are the three types of thresholds
Type of disease
Population density
Vaccine effectiveness
Why is there a decrease in the vaccination in developed countries
Low up take due to controversy
Why is there a decrease in the vaccination in developing countries
Can’t afford it/poverty
What is antigenic variation
When some pathogens can change their antigens
Why is antigenic variation a problem
If your antigens change then your memory cells won’t recognise them meaning they aren’t effective , increasing your chance of getting ill again
Why is influenza still a problem and why do people still need to be vaccinated each year
Antigenic variations
