vaccination Flashcards
1
Q
what are the two types of immunity?
A
active and passive
2
Q
what is herd immunity?
A
- when the majority of a population is vaccinated against a pathogen, it breaks the pathogen chain of infection
- this means the virus disappears as its unable to pass from person to person
3
Q
give examples of when HIV can spread from one infected person to another.
A
- during sexual intercourse
- when an intravenous drug user shares needles
- across the placenta of an infected mother
4
Q
what is a vaccination?
A
an injection of antigens from a micro-organism that stimulates the formation of memory cells
