Vaccines

Question 1

What is a vaccine?

Answer 1

A small amount of weakened or dead pathogens (or just antigens) are introduced in the mouth or by injection.
- exposure to the antigens activates the b cells to go through clonal expansion and differentiation (clonal selection)

Question 2

What is herd immunity?

Answer 2

• if enough of the population is vaccinated, the pathogen cannot spread easily amongst the population
• this protects those who are unable to get vaccinated. for example, if they are too ill, have a lowered immune system or too young