Lecture 22+23: Immunizations Flashcards
the process of producing a state of resistance or protection from a pathogenic organism or toxic substance
immunization
passive immunization
ready made antibodies
provides immediate immunological protection
- does NOT activate immune system
- does NOT generate memory response
- protection is transient
natural passive immunizations
- maternal antibodies are transferred to offspring across the placenta and or in colostrum/milk
- goal is to protect the fetus until its own immune system is mature
active immunizations
induced production of body’s own antibodies and effector T cells as a result of exposure to pathogen or vaccine
- repeated exposure increases antibody titers
artificial passive immunizations
antibodies come from other sources
- goal is to protect an individual from a challenge before their immune system can be activated
natural active immunizations
exposure to infectious agents results in antibody and memory T cell production
artificial active immunizations
administration of vaccines w/ antibodies
antibodies and memory T cells develop
what immunoglobulins are transferred from maternal antibodies to offspring in colostrum and or milk
Secretory IgA and IgG (and / or IgM)
- Secretory IgA remains in the gut
what does it mean for neonates to be agammaglobulinemia?
they are dependent on antibodies absorbed into the bloodstream from maternal colostrum
- newborns don’t have any maternal antibody protection they are immunologically naive at birth
If neonates don’t receive adequate colostrum, they are at a higher risk of…?
infection
infectious disease is a major cause of death in neonates w/ FPT.
How does artificial passive immunization work
- serum is collected from an animal that has been hyperimmunized w/ the desired antigens
- immunoglobulins are harvested and purified
then given to a patient to provide immediate protection
Risks to consider w/ artificial passive immunizations
potential hypersensitivity reactions can occur
– horse antibodies are seen as non-self to canines
- may prevent patient from mounting an active immune response to the antigens
ex: tetanus antitoxin, snakebite antivenin
how does tetanus antitoxin work
it is an artificial passive immunization used to prevent and treat tetanus in animals
- the antitoxin neutralizes the toxin and confers immediate passive immunity for 1-2 weeks
what type of toxin is tetanus, where does it come from
a potent neurotoxin that inhibits muscle relaxation
- produced by Clostridium tetani
what is active immunity?
immunity that develops in response to an infection or vaccine
preventative vaccines are what type of immunization
artificial active
do vaccines offer sterilizing immunity
no, you can still get a low level of infection
vaccination means the animals is significantly less likely to experience severe disease
characteristics of live (infectious) vaccines
- replicate in host
- can sometimes be single dose
- less stable, shorter shelf life
- can potentially cause disease
- induces better immunity
characteristics of non-living (non-infectious) vaccines
- cannot cause disease and are stable
- less robust immunity
- often require multiple doses
what are live virulent vaccines?
- relatively rare, high risk of causing disease w/ live pathogen
- vaccination can help reduce clinical signs
- ex: Orf Vaccine (Orf = contagious pustular dermatitis or scabby mouth common in sheep and goats)
live attenuated or modified live vaccines
contain intact, viable (living) organisms but their virulence has been reduced
they induce low-level infections and replicate but do not induce significant disease or tissue damage in immunocompetent patients
what is the most common type of vaccine in veterinary medicine
modified live vaccines
what is a tradition method of attenuation
repeated culture of the pathogen in a non-host strain so that the virus no longer grows well in original host cells
what are 2 examples of traditionally attenuated MLV
Bovine coronavirus vaccine (BCV) protects calves against enteric disease
DA2PP vaccine (protects dogs against distemper, adenovirus type 2, parainfluenza virus, and parvovirus)
how can CAV-2 protect against both CAV-1 and CAV-2
Cross protection
what type of immunization may have deletions or modifications of key virulence factors
live attenuated or modified live
ex: Aujesky’s disease vaccine has a genetic deletion of thymidine kinase (TK) or glycoprotein E (gE)
DIVA vaccines
Differentiation between Infected vs Vaccinated Animals AKA Marker vaccines
what vaccine type allows for the differentiation b/w an infected vs vaccinated animals
DIVA (marker) vaccines
Bovine coronavirus and DA2PP are examples of what type of vaccines
Live attenuated / modified live
what type of vaccine is the pseudorabies (aujeszky’s disease) vaccine
live attenuated and a DIVA
what type of vaccine is the Orf Vx
Live virulent
what type of vaccines are Infectious bovine rhinotracheitis, Rabies, Equine West Nile
Inactivated/killed vaccines
what type of vaccine is the tetanus toxoid vaccine
toxoid
what type of vaccine is the Streptococcus equine (strangles) Vx
Subunit vaccine
type of vaccine that contains parts/portions of an organism
subunit vaccines
what are adjuvants
substances that promote antigen persistence in tissue or enhance the immunogenicity of an antigen
what type of vaccines are DIVA Vxs
Live attenuated / Modified Live
what types of vaccines often require an adjuvant to maximize effectiveness
Inactivated/killed Vxs
added to Vx to augment the immune response to antigens
adjuvants
How to adjuvants help the immune system respond to antigens
increased persistence of antigen
PRR activation
enhanced antigen uptake
increased antigen presentation to T cells
recruitment of immune cells
what type of vaccines contain genetically engineered DNA
Naked (plasmid) DNA vaccines
Melanoma therapeutic Vx for dogs is what type of Vx
Naked (plasmid) DNA vaccine
what type of vx is the Recombinant FeLV vx
Vectored Vx
type of vaccine in which recombinant plasmid DNA is engineered and inserted into host organism in culture
host cells synthesize recombinate proteins of interest
vaccine contains purified recombinate proteins
recombinant subunit Vx
vectored Vxs don’t require what
adjuvants
what type of immunization uses antitoxins/antivenins or pooled immune globulin
passive artificial
where are Neonatal Fc receptors (FcRn) expressed and what do they bind
surface of enterocytes within the duodenum
they bind maternal IgG
what does it mean for neonates to be agammaglobulinemic
they do not have any maternal antibody protection; they are immunologically naïve at birth
what is FPT (failure of passive transfer)
maternal antibodies fail to cross the placenta, so newborns are immunologically naive at birth.
Neutralizes a toxin, confers immediate passive immunity for 1-2 weeks.
antitoxin
passive artifical
What kind of immunization occurs via infection with a pathogenic substance?
natural active
what is the goal of recombinant vaccines
to induce both humoral and cell-mediated immunity to the antigens
goal is to protect the fetus until its own immune system is mature, such as the transfer of maternal antibodies.
passive natural
__________ vaccines are often less immunogenic and stimulate only humoral (antibody) responses. Often require the use of an ___________ to maximize the effectiveness of the immune response to the vaccine components.
Killed
adjuvant
Risks of artificial passive immunization are a potential _______________ reaction occurring, and prevention of the patient from mounting an _______ immune response to antigen(s).
hypersensitivity
active
Vaccines that contain parts/portions of an organism and an adjuvant. Ex) strangles vaccine in horses is a suspension of concentrated, purified M-protein from the bacterium, but no intact bacterial cells.
Subunit (Fractional) Vx
Process that moves materials across a cell in a vesicle, how maternal antibodies cross the placenta
transcytosis
Expressed in internal vesicles and when acidified, can bind maternal IgG
Neonatal Fc Receptors (FcRn)
What type of live vaccine have pathogens that induce low-level infections and replicate, but do not induce significant disease or tissue damage in immune competent patients.
Live attenuated/modified
What kind of immunization occurs via vaccination?
artificial active
What type of vaccine can be composed of an antigenically-related organism to provide cross-protection?
modified live
A type of recombinant vaccine that contains genetically engineered DNA.
Immunogenicity gene is inserted into a plasmid expression vector, and the vaccine contains isolated/purified recombinant plasmid DNA.
Naked (Plasmid) DNA Vaccines
what are the 3 types of recombinant vaccines
- Naked DNA vaccines
- Recombinant subunit vaccines
- Vectored vaccines
Vaccines that contain harvested/purified recombinant protein(s) - recombinant plasmid DNA is engineered and inserted into a host in the organism in culture, then host cells synthesize the recombinant protein(s) of interest
recombinant subunit vaccines
