virus vaccines Flashcards
what is a subunit vaccine?
a vaccine containing no live virus. uses a virus proteins often a capsid. zero chance of catching disease, yet least effective due to fewer epitopes
how do virus vector vaccines work?
they utilise an attenuated virus to present antigens to the immune system. hard to produce, not effective as poorly antigenic
howdy inactivated virus vaccines work? give an example
- expose virus to a denaturing agent or heat
- many epitopes, better immunogens, stable
- little risk
- denaturation may lead to loss of antigenicity
salk polio virus
what is a live virus vaccine?
a virus with reduced pathogenicity, aims to stimulate an immune response without disease
what are the advantages of live virus vaccines?
- good immunogens
- induce long lived, appropriate immunity
what are the disadvantages of live virus vaccines?
- unstable (can revert back to virulence)
- not possible to produce in all stages
- contamination possible
- immunocompromised people cannot receive
how are live vaccines prepared?
- grown inhuman diploid cells
- cultures seeded from safe virus stocks only one or two passages from the seed
what are the routes of vaccine administration?
- oral
- subcutaneous
- intramuscular
give examples of problems with vaccines
- sensitisation e.g. dengue
- reversion in live vaccines
- rare complications
- development is difficult
