Active Immunity

Question 1

What is active immunity?

Answer 1

Active immuniy is protection that is produced by an individual’s own immune system, and is usually long-lasting.

Question 2

How can active immunity be acquired?

Answer 2

By natural disease or by vaccination

Question 3

Active immunity can be divided into:

2

Answer 3

Antibody mediated

Cell-mediated

Question 4

What cells are antibody-mediated responses produced by?

Answer 4

B lymphocytes (B cells) and their direct descendants, known as plasma cells.

When a B cell encounters an antigen that it recognises, the B cell is stimulated to proliferate and produce large numbers of lymphocytes secreting an antibody to this antigen. Replication and differentiation of B cells into plasma cells is regulated by contact with the antigen and by interactions with T cells (a type of lymphocyte), macrophages and complement.

Question 5

What cells are cell-mediated responses produced by?

Answer 5

T cells

Cell-mediated immunity is controlled by a subset of lymphocytes called T lymphocytes or T cells. T cells mediate three principal functions: help, suppression and cytotoxicity. T-helper cells stimulate the immune response of other cells (i.e. T cells stimulate B cells to produce antibodies). T-suppressor cells play an inhibitory role and control the level and quality of the immune response. Cytotoxic T cells recognise and destroy infected cells and activate phagocytes to destroy pathogens they have taken up.

Question 6

True or false:

Acquisition of anti-RSV antibodies following a viral upper respiratory tract infection is an example of active immunity?

Answer 6

True

Question 7

True or false:

Transplacental IgG against VZV is an example of active immunity?

Answer 7

False

Transplacental = passive immunity

Question 8

True or false:

IV ceftriaxone given to a child with sspected meningococcal sepsis is an example of active immunity?

Answer 8

False

antibiotics, not giving child immunity, just killing bacteria

Question 9

True or false:

IV immunoglobulin for an immunocompromised child exposed to chicken pox is an example of active immunity?

Answer 9

False

Immunoglobulin for immunocompromised does not give immunity

Question 10

True or false:

Cell mediated response to BCG vaccine is an example of active immunity?

Answer 10

True

Question 11

True or false:

Seasonal flu vaccine is an example of active immunity?

Answer 11

True