Vaccines

Question 1

Vaccine Efficacy

Answer 1

VE (%) = (ARU-ARI)/ARU

Question 2

How do vaccines work?

Answer 2

Ag encounter in tissues. DC migrates into lymphoid tissue, activates T cells (both CD4 and CD8). T cells activate B cells, some of which turn into plasma cells to produce Igs.

Question 3

Class 1 MHC recognized by?

Answer 3

CD8 killer T cell

Question 4

Class 2 MHC recognized by

Answer 4

CD4 helper T cell

Question 5

Why are multiple doses of a vaccine given?

Answer 5

To dramatically increase antibody levels. After a booster, there are shorter lag phases, higher Ab levels, and longer persistence.

Question 6

What do bacterial vaccines promote?

Answer 6

Antibodies to neutralize toxins, promote opsonization/phagocytosis/complement-mediated lysis.

Question 7

What is the peak incidence of H. influenzae, s. pneumo, n.meningitidis? Why?

Answer 7

6-18 mo. Before 6mo, there are still maternal IgGs.

Question 8

Is it possible to develop a vaccine to an encapsulated organism?

Answer 8

Yes of course! Just vaccinate against capsular antigens.

Question 9

Are pure polysaccharide vaccines effective?

Answer 9

Yes, but not in children under 2 years old.

Question 10

How to induce immune response to polysaccharide ag in children?

Answer 10

Conjugate to a protein like tetanus toxoid.

Question 11

How does a Pr-Ps vaccine induce better immunity?

Answer 11

Pr-ps is internalized, protein is degraded and presented to T cells, which will produce cytokines to have B cells make antibodies to PS component.

Question 12

Adjuvant?

Answer 12

Added substance that enhances immune response to a target antigen by inducing concurrent inflammatory response/slowing release of antigen. Mineral oil/alum.

Question 13

Vaccines that contain adjuvants are generally administered which way?

Answer 13

IM

Question 14

What vaccine is least effective?

Answer 14

Pertussis, immunity is short lasting.