Vaccination (6) Flashcards
What are some viral mechanisms to avoid the immune response?
latency in protected sites
growth in immune cells
antigenic drift and shift
suppression of class I MHC molecules to prevent CTL mediated killing of infected cells
production of proteins that block signaling of cytoikkine and antiviral pathways for interferon
What are the 3 main approaches to making a vaccine?
using a whole virus or bacterium
parts that trigger the immune system
just the genetic material
T/F: All vaccines should satisfy requirements of efficacy, purity, potency, and safety
TRUE
What is the “historical vaccines”?
Jennerian (use of closely related less virulent viruses)
What are “work horse vaccines”?
live attenuated (slowed) vaccines
inactivated vaccines
What are “new generation vaccines”?
recombinant and genetically engineered vaccines
nucleic acid vaccines (DNA & mRNA)
Most vaccines on the market are either inactivated or live ______, but _____ are now in use
attenuated
recombinant vaccines
What’s an example of a live attenuated vaccine?
canine distemper
What are live attenuated vaccines?
the modified live virus replicates in the host
produces longer-lasting immunity similar to that of natural infection
generally better immunogens
usually most successful
What are the advantages of attenuated vaccines?
single dose may be effective
can be given by a natural route, stimulating local and systemic immunity
produces long-lived immunity
inexpensive
What are the disadvantages of attenuated vaccines?
possible reversion to virulence
possible spread to in contact animals and fetus
possible contaminating viruses or mycoplasmas
may not be attenuated for all species
What are the advantages of inactivated vaccines?
stability
no danger of spread
no problem with viral interference
fatal viruses can be controlled
What are the disadvantages of inactivated vaccines?
multiple doses often required to protect
no local immunity or interferon produced
high concentration of antigen causes them to be expensive
immunity often short-lived
any non-inactivated virus can cause disease
What are adjuvants?
agents used to enhance the immunologic response to inactivated vaccines
What do adjuvants cause?
a slower release and degradation of antigens and stimulate phagocytosis
_____ is one widely used adjuvant but other products such as iscoms are used
Aluminum hydroxide
Who researched the human genome project?
Craig Venter
What are gene deleted vaccines?
virulent genes are removed or modified - so not virulent
attenuated