Lab Exam (Vaccines) Flashcards
What are inactivated vaccines composed of?
composed of chemically inactivated, irradiated, or heat-killed pathogen
How are pathogens killed or inactivated?
- heat treatment
- irradiation
- formalin treatment
What is the mechanism of heat treatment?
high temperatures can kill bacteria
What is the mechanism of irradiation?
powerful irradiation can permanently damage the pathogen’s DNA
What is the mechanism of formalin treatment?
formalin is formaldehyde solution that crosslinks or covalently modifies proteins and DNA
What is the best method for killing or inactivating pathogens?
irradiation, produces a vaccine that best mimics the actual pathogen as this process does less damage to the associated antigens, allowing the inactivated virus or bacterium to closely mirror the live pathogen
How many doses do you need for an effective inactivated vaccine?
two doses
What are live attenuated vaccines composed of?
composed of a pathogen that has not been inactivated but is incapable of normal survival or pathogenesis in the host
What are the infection capabilities of the attenuated pathogen?
pathogen has lost its ability to cause disease but does not kill the pathogen
What are the benefits to a live attenuated vaccine?
- allows vaccine to more closely mimic an infection without causing negative reactions
- activates the cellular arm of the adaptive immune response
- induce production of secretory IgA and IgG
What are the negatives to a live attenuated vaccine?
induces severe complications in immunocompromised individuals
What are toxoid vaccines composed of?
vaccines containing inactivated exotoxins to simulate an adaptive immune response that involves production of neutralizing antibodies that block normal exotoxin activity
What are exotoxins?
causative agents of disease, activation of an immune response capable of neutralizing these toxins
How are exotoxins inactivated?
by formalin treatment or heat
What is the function of exotoxins?
activates B cells capable of producing toxin-neutralizing immunoglobulins
What are subunit vaccines composed of?
vaccines composed of a cell-surface antigen/ adhesion molecules of a pathogen; designed to stimulate the production of neutralizing immunoglobulins that block pathogen interaction with target cells
What is the function if neutralizing immunoglobulins?
recognize adhesion molecules that can block infection by the intracellular pathogen
What is the function of adhesion molecules?
activates B cells that can generate neutralizing antibodies to the specific cell adhesion molecules
What are conjugate vaccines composed of?
vaccines composed of a weak antigen (incapable of mounting a robust adaptive immune response) coupled with a stronger antigen that can activate a protective primary immune response
What is the mechanism of the coupled antigens?
drive the activation of T cells that respond to the toxoid and B cells that respond to the polysaccharide
How many doses do you need for an effective conjugate vaccine?
requires boosters to promote full protection against the pathogen
What are the components of conjugate vaccines?
polysaccharide coat (weak antigen) and toxoid (strong antigen)
What are recombinant vector vaccines composed of?
vaccines that take advantage of the ability to isolate a gene capable of encoding an antigen from a pathogen and placing the gene into a plasmid or harmless or attenuated virus
What is similar to a recombinant vector vaccine?
acts in a similar manner to a live attenuated vaccine, but also expresses the antigen of interest with the intent of inducing a protective immune response against the antigen
