Scientic Basis Of Vaccines Flashcards
What is herd immunity memory boosted by?
Periodic outbreaks of disease in community and vaccines
What do parenteral vaccines lead to?
Poor mucosal immunity
When are antibodies sufficient?
Short term protection
When is memory essential?
Long term protection
What does monotypic mean?
Surface antigens remaining the same generally so vaccination (or infection) gives lifelong immunity
What does polytypic mean?
Surface antigens change and immunity is readily overcome
What are the types of vaccine?
Live,attenuated
Killed whole organism
Subunit
What are examples of live, attenuated vaccines?
BCG
MMR
yellow fever
How can you attenuate the live vaccines?
Culture it in a foreign host many times (add mutations)
Chemically cause mutations to attenuate it
Genetically engineer to create knockouts lacking genes for virulence
What are the issues with live attenuated vaccines?
Vaccine may mutate back to original form
Generally needs to be kept cold
Why are live attenuated vaccines good?
Useful for producing CTL memory cells because they can infect APCs
How are killed whole organism vaccines killed?
Heat or chemicals
What are examples of killed whole organism vaccines?
Pertussis Influenza Polio Cholera HepA
What are the issues with killed whole organism vaccines?
Need boosting to get good protection
What are the individual components of bacteria that are used in subunit vaccines?
Proteins
Toxoids
Peptides
Polysaccharide
What are bacterial toxins inactivated with for use in vaccines?
Formaldehyde
What are the features of bacterial capsular polysaccharides as vaccines?
Poor antigens
Short term memory
No T cell immunity
How can you enhance immunogenicity?
Protein conjugation
How does enhancing immunogenicity work?
If you just use the polysaccharide theres only an antibody response
If you conjugate it to another cell then T cell binding occurs
What are vaccine adjuvants?
Things you add to vaccines to make them more immunogenic
What do vaccine adjuvants do?
Enhance immune response to antigen
Promote uptake and antigen presentation
Stimulate correct cytokine profiles
Where do you get passive immunity from?
Maternal transfer or serum from another source
