Lec 17: Virus Vaccines Flashcards
The term vaccination is derived from
the Latin word vacca, meaning cow.
The immune response against cowpox virus had
protected against smallpox virus, the protection resulting from related antigens in the two viruses.
A vaccine contains
material intended to induce an immune response, and this may involve both B cells and T cells
The purpose of most viral vaccines is to
induce long-term immunity against the virus by establishing immunological memory that will be triggered if the virus ever invades the body.
What is required in order to establish strong immunological memory?
highly immunogenic virus materials
Effective vaccines =
Polio, rubella, rabies and foot and mouth disease
Vaccines yet to be developed =
HIV-1, hepatitis C, Ebola and the herpes simplex viruses
What makes a good immunogen? (4)
- ) Foreignness
- ) Molecular size
- ) Chemical composition and heterogeneity (ex: DNA < protein)
- ) Degradability
7 Types of vaccines:
- Live attenuated virus vaccines
- Inactivated virus vaccines
- Virion subunit vaccines
- Live recombinant virus vaccines
- Virus-like particles
- Synthetic peptide vaccines
- DNA vaccines
Live attenuated virus vaccine risk:
may reverse to virulence
(Live attenuated virus vaccines) Steps (5):
- Wild type
- monkey kidney cells
- plaque purifications
- attenuated strain
- vaccine
Inactivated virus vaccines essential 2 steps:
- ) Mass production of virulent virus
2. ) Inactivation of the virus
(Inactivated virus vaccines)
Key =
finding the combination of chemical concentration and reaction time to completely inactivates the virus, but leaves its antigens sufficiently unchanged that they can still stimulate a protective immune response.
(Virion subunit vaccines)
Steps (5):
- influenza visione
- inactivation of infectivity
- detergent
- sucrose gradient
- vaccine
(Live recombinant virus vaccines)
Example:
ex: recombinant vaccinia virus (smallpox) that expresses the rabies virus G protein
