58 Vaccines 1

Exam 2

what is the goal of a vaccine

prevetn infection

prevent disease

decrease severity of disease

eradicate the pathogen

protect against cancer

what are vaccines

an antigen

usually protein antigen

or nucleic acids that code for protein antigens

what do vaccines directly cause generation of

memory B and T cells

what does the type of immune responses needed depend on

the type of pathogen being targeted

what is a toxoid vaccine

inactivated toxin

what is an inactivated pathogen vaccine

killed

uses the whole, live organism

what is a live attenuated vaccines

modified life vaccine

uses whole, live organism

what is a subunit vaccine

protein subunit vaccine

DNA or RNA subunit vaccine codes for proteins of the microbe

what are examples of toxoid vaccines

Clostridium Tetani: bacteria produces tetanus toxin, toxin is inactivated and used as vaccine

rattle snake venom: inactiavted and used as a vaccine to protect against bites

who regulates animal vaccines in the US

USDA

what can the route of administration for vaccines efffect

the immune response generated

what are the different routes of vaccines

intramuscualr

subcutaneous

intranasal

oral

what are adjuvants

substances added to vaccines to maximize their effects

especially with killed whole organisms or highly purified antigens

what are the types of adjuvants

depot

particulate

immunostimulatory

mixed

what problems can depot adjuvants caused

delay antigen removal

prolonged immune response

what is a depot adjuvant

freunds incomplete adjuvant

a water in oil emulsion

what are particulate adjuvants

antigens embedded in lipid nanoparticles

what are the problems caused by particulate adjuvants

promote antigen uptake by APCs

enhance t helper cell responses that can promote both CMI and humoral responses

what is immunostimulatory adjuvants

molecules from microbes (LPS, PAMPs)

what problems can be caused by immunstimulatory adjuvants

promote cytokine production by host cells

enhance t helper cell responses that can promote both CMI and humoral responses

how are inactivated vaccines killed

chemical, heat, or radiation

what are the pros of killed vaccines

more stable and safer than lie

cant mutate back to virulence

cant infect the host\

easy storage

can be given to immunocompromised animals

what response do killed vaccines stimulate

Antibody response

Th2 dominated

what are the cons of killed vaccines

often require adjuvants

stimulate weaker responses

may need bosters

killing them may destroy epitopes

can sometimes promote immune-complex disease

examples of adjuvant problems

severe inflammation: vaccine induced feline sarcomas

hypersensitivity allergic response in dogs

what do modified live vaccines contain

a modified virus or intracellular bacterium organisms that infect the host and replicate inside host cells

what vaccine is the closest to a natural infection

Modified live vaccines

elicit stronger cellular and antibody responses

what are some examples of modified live vaccines

brucella aborus

canine distempter

how are microbes modified for modified live vaccines

non genetic engineering: grow under conditions that result in genetic changes with no virulence

genetic engineering: gene deletions or modifications

pros of modified live vaccines

many epitopes

good CMI and humoral responses

often gives life long immunity

no adjuvant needed

cons of modified live vaccines

can be hazardous because its lice

may pose a risk to fetus if given during pregnancy

may be a risk to veterinarian if injected

needs careful handling

may be risk for immunocompromised

what si the problem with attenuated B. abortus vaccines

have residual virulence

what is b. abortus

can cause abortion in cows, orchitis in bulls (inflammation of testicles)

an intracellular bacterium- killed vaccine would not work

vaccine can cause abortion and drop in milk production

not for pregnant heifers or male bulls

what happens if a human is vaccinated with B. abortus

possible systemic fever and abortion

what is a DIVA vaccine

to differenitate between infected animals and those vaccinated

test for the field strain, not the vaccine strain

what is the DIVA vaccine for B. abortus

RB51

tests for antigens expressed in field strain, but not vaccine strain

what is injected with a subunit vaccine

proteins of a microbe

DNA that codes for microbial proteins

mRNA that codes for microbial proteins

what is a recombinant vectored vaccines

a subunit vaccine where a living microbe is the delivery system

how are subunit vaccines generated via non-genetic engineering

isolate and purify immunogenicity proteins from pathogens and inject proteins

often require adjuvants

what type of vaccine is e.coli purified pili

subunit, non-genetically engineered

how are subunit vaccines generated via genetic engineering

identify immunogenicity microbial proteins

identify genes that code for immunoigenic proteins

then: insert the genes into plasmid insert plasmid into bacterium, baterium makes proteins, proteins are purified

often needs adjuvant

what are some examples of subunit vaccines

west nile vaccine for horses

H5N1 flu in poultry

covid mRNA vaccines

what is the vaccine for Feline Leukemia PVirus

protein subunit, recombinant proteins

was 1st vaccine with recombinant

what are vectors

harmless, living virus or bacterium into which DNA or RNA from the pathogen has been inserted

what are replicating vectors

not only infect host cells but also replicate in them

induces longer lasting immunity

what are non replicating vectors

infect host cells but cannot replicate in them

what type of vaccine is used in wild raccoons for rabies

live expression vectors in the rabies oral vaccine

what are potential disadvantages of DNA vaccines

DNA might integrate into host genome and be detrimental to host

thus most vaccines would rather use mRNA viruses because they stay in the cytoplasm

benefits of mRNA vaccines

high efficacy: prevent severe illness

rapid development: dont require growth in cultures

adaptability: can be changed to target new variants

safety profile: no live viruses

induction of a strong immune response: simulate cellular and humoral immunity

challenges of mRNA vaccines

stability and storage: mRNA is unstable, needs to be kept cold

delivery mechanisms: delivery is complex

public perception: people suck

regulatory and logistical hurdles

how is the unstable quality of mRNA fixed in vaccines

embed mRNA into lipid nanoparticles

nanoparticles cause delayed degredation of mRNA and facilitate entry into cells

how do lipid nanoparticles (LNPs) work

enter host cell through endocytosis

interact with cell membrane through hydrophobic interactions

phagocytic cells pahgosytose nanoparticles

what is recombinant DNA technology

using the enzymes to manipulate and isolate DNA segments of interest

can be used to combine or splice DNA from different species

what are all DNA and RNA vaccines the result of

recombinant technology

what is duration of immunity

the length of time a vaccine establishes a protective immune response against disease following exposure to pathogen

what information is not required for USDA approval

duration of immunity information

what vaccine does the USDA require DOI information

rabies

new vaccines with no pre-existing products