Determinants of Vaccine success Flashcards
Describe a live, attenuated vaccine
live organisms which, through culture under certain conditions, have lost their virulent properties
Describe a whole cell inactivated vaccine
organisms innately capable of causing disease that have undergone treatment with chemicals or heat, which has rendered them unable to cause the disease
Describe a toxoid vaccine
illness-causing components produced by pathogens that have been inactivated
Describe a subunit vaccine
a part of the organism, rather that the whole organism, is used to create an immune response
Example of a live attenuated vaccine
Measles
Example of a protein vaccine
Tetanus toxoid
Why do we not use live BCG in HIV+ babies
- vaccine efficacy not known
- serious adverse effects (BCGosis)
- benefit/risk ratio not known
Why do you not give babies measles vaccine?
Maternal Abs may interfere with vaccination
How might maternal Abs affect vaccination
- IgG actively transferred through the placenta
- igG competes with infant B cells for vaccine Ag
- inhibition may be more marked for live attenuated vaccines (neutralized by small Ab titers)
- T cells usually not inhibited
Known properties of immunity associated with early life
- limited magnitude of Ab responses to polysaccharadies
- limited magnitude of Ab responses to proteins
- short persistence of Ab responses to proteins
- shorter duration of immune memory
- limited IFN responses
Why conjugate a polysaccharide vaccine with protein?
Induces T cells to help the B cells become plasma and memory B cells
Examples of conjugated vaccines
- Pneumococcal
- Hiv
- Meningococcal vaccine
Things to consider when deciding age to vaccinate
- vaccination is often more effective at later age
- maternal transfer of Abs might interfere
- longer periods between boost are better
- multiple vaccinations simulatneously may cause interference
- acute illness may interfere with vaccination
Why is simultaneous vaccination useful?
- minimize clinic visits
- protection against multuiple vaccine-preventable diseases is achieved
Adjuvant that enhances Th1 response
GLA-SE
