Vaccines

Question 1

Describe the difference between active and passive immunity.

Answer 1

Active requires memory cells whereas passive doesn’t.
Active is slower and takes longer to develop whereas passive is faster acting.
Active gives long term immunity whereas passive gives short term immunity.
Active antibody is produced and secreted by B plasma cells whereas passive antibody is introduced from another organism e.g. breast milk.
Active requires initial exposure to antigen whereas passive has no exposure to antigen.

Question 2

When a vaccine is given to a person, it leads to the production of
antibodies against a disease-causing organism. Describe how.

Answer 2

1) Specific B lymphocyte with complementary receptor binds to antigen.
2)Specific T helper cell binds to antigen presenting cell and stimulates B cell.
3)B lymphocyte divides by mitosis to form clones.
4)Some differentiate into B plasma cells which release antibodies.
5)Some differentiate into B memory cells.
6)On secondary exposure to antigen, B memory cells rapidly divide by mitosis to produce B plasma cells.
7)Theses release antibodies faster and at a higher concentration.

Question 3

What is a vaccine?

Answer 3

Small amount of weakened or dead pathogen or antigen that is introduced in the mouth or by injection that stimulates the formation of memory cells.

Question 4

Explain how vaccines provide protections for populations against disease.

Answer 4

Herd immunity - large proportion of population is vaccinated reducing the spread of pathogen. Large proportion of population immune so they don’t become ill from infection. Fewer infected people to pass pathogen on .

Question 5

What is passive immunity?

Answer 5

Passive immunity is when the antibodies are introduced into the body. The pathogen doesn’t enter the body so plasma cells and memory cells are not made. You don’t have any long term immunity. For example, antibodies passed to a fetus through the placenta or through breast milk to a baby.

Question 6

What is active immunity?

Answer 6

Active immunity is immunity created by your own immune system following exposure to the pathogen or its antigen.

Question 7

What are the two types of active immunity?

Answer 7

Natural active immunity
Artificial active immunity.

Question 8

What is natural active immunity?

Answer 8

Following infection and the creation of your own antibodies and memory cells.

Question 9

What is artificial active immunity

Answer 9

Following the introduction of a weakened version of the pathogen or antigen via a vaccine.