Vaccines Flashcards
____: Stop transmission of pathogen by vaccination of “large enough % of people”
Herd Immunity
In Herd Immunity, percentage of people needed to be vaccinated depends on the ____ of the pathogen
attack rate
What disease has a high attack rate and, therefore, requires increased percentage of vaccinated/immune individuals to slow down transmission of disease?
Measles
What are the three types of whole organism vaccines?
1) Killed/inactivated
2) Live attenuated
3) Live heterologous species
What are the types of subunit/purified macromolecules?
1) Toxoid
2) Polysaccharides
3) Subvirion
4) Recombinant
5) Naked DNA
Two major vaccine groups?
Whole Organism vs. Subunit/Purified Macromolecules
Pathogen purification, then inactivation by chemical/physical means leaves pathogen unable to replicate. What vaccine uses this strategy?
A. Toxoid
B. Subvirion
C. Killed/Inactivated
C. Killed/Inactivated
Why can’t we use killed/inactivated vaccines against ALL pathogens?
Dead pathogens are NOT processed by immune system like living pathogen
1) **Adverse immune responses may arise
2) Immune responses that do develop may not be protective
Example: Killed Measles Vaccine
Three advantages of Killed/Inactivated Whole Organism Vaccines?
1) Stable - do not require cold chain
2) Sufficient Ab response (humoral)
3) Safe to give to immunocomp or pregnant people
Disadvantages of Killed/Inactivated Whole Organism vaccines?
1) Require boosters (weakly immunogenic)
2) Predominately promote Th2-dependent (humoral) responses
True or False: Killed/Inactivated Whole Organism vaccines undergo exogenous processing and present on HLA II
True
- Also have humoral immunity
What is strategy used by Live Attenuated Whole Organism?
Take original pathogen and culture it in vitro so it LOSES its VIRULENCE
After you have an avirulent pathogen, you can administer vaccine (which is LIVE, but lacks VIRULENCE)
What are the advantages and disadvantages to live attenuated whole organism vaccines?
Advantages
- Processed by immune system like actual infection and elicits SUSTAINED immune response (similar to actual infection)
Disadvantages
- Not very stable; may require cold chain
- May revert from virulent form to virulence (esp in immune compromised)
True or False: Immunocompromised people can be given live attenuated vaccines
False
- cannot eradicate quickly
- can cause disease in host
____ is a type of live vaccine where one pathogen is introduce in order to provide protection against a different one. The vaccines are pathogens of other animals that either
a) do not cause disease or
b) cause mild disease in organism being treated
Heterologous vaccine (smallpox - vaccinia virus)
An advantage of a live whole cell vaccine over a killed vaccine is:
A. Can be administered to immunosuppressed
B. More stable
C. Induces both humoral and CMI
D. Reverts back to virulent form
E. All of the above
C. Induces both humoral and CMI
How do toxoid vaccines work?
Exotoxoid is chemically modified to take away site responsible for toxicity; toxoid remains;
Three examples of toxoid vaccines?
Tetanus, diptheria, botulism
What is the goal of polysaccharide vaccines?
Increase antibody against polysaccharide antigens of bacteria
How are polysaccharide vaccines made?
bacterial cell + capsule => grow in pure culture => separate and purify capsule => inject purified polysaccharide
After a polysaccharide vaccine, one has elevated levels of___ and __
Ab and C’ for opsonins
How do you make subviron vaccines?
Protein exposed to detergent => purify the virion within envelope!
Which part of the virus is used in subvarion vaccine?
virion/virus particle
What type of vaccines use molecular biology to make proteins from pathogen?
Recombinant Vaccines
- uses virus like particle that are purified lacks genetic material)
The SARS-CoV-2 (J&J and AstraZeneca) vaccine is an example of: _____
Recombinant Vector Vaccines
_____: vaccines that use molecular biology to place virulent gene from pathogen into an avirulent microoorganism
Recombinant Vector Vaccines
How was the COVID-19 Oxford Vaccine developed?
1) Took chimp adenovirus and modified it, so it would not cause disease
2) Gene that encodes spike in SARS-Cov-2
3) Incorporated gene into viral vector
4) Cells express spike protein
5) Body makes antibodies against spike proteins
6) Induces immune response
