Lecture 8: Vaccines Flashcards
What are killed or inactivated virus vaccines
most viral vaccines contain the disease-causing virus, but in a form that does not cause severe disease
Cannot replicate because they have been treated chemically with formalin or physically with heat or
irradiation (Polio (IPV))
Live attenuated virus vaccine
mutant form of live virus that grows
poorly in human cells and is no longer pathogenic to humans
examples:
measles
- mumps
- oral polio (OPV) – not given any longer
- most viral vaccines
Why do Live attenuated virus vaccines work well?
bc protective immunity that killed
virus vaccines because the attenuated virus can to some extent infect cells and replicate, mimicking a real infection
What are Subunit vaccines?
use antigenic fragments to stimulate an immune response. Such as surface protein.
Used in recombinant DNA technology.
HepB subunit vaccine was one of the first
examples:
-Haemophilus influenzae type b (Hib)
- Pneumococcal
- Hepatitis B
What are DNA vaccines?
introduce plasmids containing the DNA sequence encoding the antigens against which an immune response is sought into appropriate tissue and
relies on the production of the target antigen
What are the advantages of DNA vaccines?
-Stimulation of both B an T cells responses
- Improved vaccine stability
- Relative ease of large-scale manufacture
The potential cons of DNA vaccines?
-The nature of the agent being immunized against
- The nature of the antigen
- Type of immune response required for protection
What is an mRNA vaccine?
designing the mRNA instructions for cells to build the
unique spike protein into an mRNA vaccine
examples :
flu, Zika, rabies, and cytomegalovirus (CMV).
What are conj. vaccines?
enable high-affinity antibodies to
be made against carbohydrate antigens
are made from polysaccharides found in the capsules of pathogenic bacteria, linked to proteins that stimulate strong adaptive immune responses.
Conjugate vaccines induce a much stronger immune response than unconjugated bacterial polysaccharides.
