3.7 Flashcards
How is immunity developed artificially
By a vaccine using antigens from an infectious pathogen
What is mixed in with vaccines
Adjuvant
What Is an adjuvant
Is mixed in with the antigens to mak3 the vaccine more effective
4 forms that antigens are used in a vaccine
Weakened pathogen
Inactivated toxin
Parts of pathogen
Dead pathogen
What is herd immunity
When a large percentage of the population are immunised which helps reduce thr dpeaf of diseases
How does herd immunity protect non immune people
Non immune people r protected as there is less chance they will come into contact with an infected individual
What does herd immunity threshold depend on
3 things
Disease
Population density
Vaccine effectiveness
Why do vaccine difficulties arise in developing and developed countries
In a developed country, there is controversy around vaccines
In under developed they can’t afford it
What us antigenic variation
Some pathogens change their antigens
Why is antigenic variation a problem
When an antigen changes, the memory cells are not going to recognise the virus so then we will keep getting the virus over and over
How does antigenic variation control the influence virus
The influence pathogen changes 8ts pathogen as it undergoes antigenic variation each year
