Vaccines Flashcards
what are the 2 responses that vaccines give?
Humoral - via antibodies to kill the free viruses (B cells mature, proliferate and generate antibodies)
Cellular - via T cells to kill infected cells - bind to antigens from MHC 1 and 11 - CD4+ and CD8+ - T killer cells attach to host surface of infected cell causing lysis
What does Vaccines do?
Have a role in developing adaptive immunity
What are the 2 types of vaccine
Live attenuated
Killed inactivated
explain the 2 types of vaccine
Virus vaccine - they infect but grow weakly - they don’t cause disease but induce a full immune response e.g influenza
Killed inactivated - Inactive virus - do not infect but still generate an antibody response e.g Hep A
what are 4 special cases of killed vaccines?
Split- virus disrupted by detergents
Multivalent subunit- purified virus protein
Recombinant vaccines - cloned and expressed proteins
DNA/RNA vaccines
what is the action of vaccines?
Recognition by B-lymphocytes and the generation of antibodies.
Binding of antibodies to the target site on the virus surface - this blocks the interaction with receptor and aggregation of virus particles.
- Complement mediated lysis
what are the 2 polio vaccines?
Sabin (live) - Made by attenuation by passage in foreign host cells, results in virus more suited to a foreign environment than original host. - grows in epithelial cells so doesn’t grow in nerve cells - provides lag and prevents replication - live but life-long immunity
Salk (inactivated) - formaldehyde fixed, can’t replicate at local sites
what is the recombinant vaccine for hep B?
clone, identify virus genome and target genome thats responsible for producing the antigen. Get gene and clone to form recombinant DNA. Infuse this into the cell in a fermentation tank to produce proteins.
Purify the target antigen nd use as a vaccine - body sees this as a foreign molecule to kick off immune system
what do DNA vaccines do?
produce a situation that reproduces a virally infected cell.
They give a broad immune response and a long lasting CTL response.
Define a vaccine
a process of induction of immunity to a pathogen by deliberate infection of a weakened, modified or related form of a pathogen which is no longer pathogenic.
