Flashcards in Vaccines Deck (14):
VE (%) = (ARU-ARI)/ARU
How do vaccines work?
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.
Class 1 MHC recognized by?
CD8 killer T cell
Class 2 MHC recognized by
CD4 helper T cell
Why are multiple doses of a vaccine given?
To dramatically increase antibody levels. After a booster, there are shorter lag phases, higher Ab levels, and longer persistence.
What do bacterial vaccines promote?
Antibodies to neutralize toxins, promote opsonization/phagocytosis/complement-mediated lysis.
What is the peak incidence of H. influenzae, s. pneumo, n.meningitidis? Why?
6-18 mo. Before 6mo, there are still maternal IgGs.
Is it possible to develop a vaccine to an encapsulated organism?
Yes of course! Just vaccinate against capsular antigens.
Are pure polysaccharide vaccines effective?
Yes, but not in children under 2 years old.
How to induce immune response to polysaccharide ag in children?
Conjugate to a protein like tetanus toxoid.
How does a Pr-Ps vaccine induce better immunity?
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.
Added substance that enhances immune response to a target antigen by inducing concurrent inflammatory response/slowing release of antigen. Mineral oil/alum.
Vaccines that contain adjuvants are generally administered which way?