Vaccinology

preparation of a weakened or killed pathogen (i.e. bacterium or virus) or portion of pathogen that stimulates antibody production or cellular immunity against the pathogen but can't cause infection

• decrease or prevent infectious disease
• greatest # in at-risk population
• no more frequently than necessary
• only if likely to be exposed
• benefits outweight risks
• protect public health

• expose naive immune system
• immune system reacts
• attacked again in the future
• immune system recognizes pathogen
• activates more quickly

cells of the immune system defending the body against both infectious disease and foreign material

one branch of WBC, there are 3 types (T, B and natural killer cells)

cell mediated immune response (helper T-cells and cytotoxic T-cells)

Humoral immune response (Plasma Cells)

lymphocyte, part of the innate immune system

protein or sugar contained on a surface of a cell, foreign object or infectious organism that the immune system can recognize and decide to attack

a protein made by a B cell that binds to specific antigen that neutralizes the antigen

innate, acquired

• (natural) 
• skin, hair, tears, normal mirobial flora, mucus, acidity of stomach, neutrophils, macrophages, natural killer cells
• first line of defense
• already active, immediate

• (adaptive)
• recognizes specific foreign invader, destroys it and remembers
• antigen specific
• includes cell mediated and humoral immunity
• passive vs active

• animal receives pre-formed antibodies made by another animal.  
• Natural (maternal transfer of antibodies. IgG, transplacental or colostrum)
• Artificial (adminitration of antiserum or antitoxin)

• exposure to antigen activates cell mediated (T lymphocytes) and humoral immunity (B lymphocytes), leads to development of memory T-cells and B-cells
• two types: natural (infection) or artifical (vaccination)

immune system attributed to the T-cell (T-lymphocytes) and cytotoxic T cells.  These T-cells are involved in regulating the antibody forming function of B-cells (B lymphocytes) as well as directly attacking foreign antigen

immune system attributed to B-cell (B lymphocytes) and the antibodies they produce.  Secreted antibodies bind to antigen on the surface of invading microbes which flags them for destruction

• high levels of maternal antibodies (can last as long as 16 weeks, usually 9-12)
• inadequate nutrition or starvation
• disease, so avoid vaccinating sick animals
• other stressors like pregnancy, parturition, lactation, weather/temp/humidity changes, travel, overcrowding, trauma, strenuous exercise, general anesthesia

• traditional: inactivated killed, modified live (attenuated)
• new: recombinant (subunit, gene-deleted, live vectored), DNA

• a vaccine composed of microbes or microbe parts (nonrecombinant subunit vaccine) that have been chemically treated or heated to kill the vaccine.  
• Doesn't replicate in body, so less response, weaker immunity
• must use massive quantities or adjuvent to improve immunity

vaccines that contain one pure or semi pure antigen

• additives added to vaccine which increase the effectiveness of the immune response to the vaccine
• not all benign, increase risk of allergic rx, anaphylaxis, injection site reactions and feline vaccination associated fibrosarcoma

• unlikely to cause disease
• cause less immunosuppression and vulnerability to other diseases
• Store for longer periods

• utilizes weakened bacteria or virus to elicit immune response
• has been altered to non-disease causing state
• alive but incapable of causing disease
• when injected they replicate creating large numbers, make greater immune response

• more amplified and longer lasting immune response
• more rapid induction of immunity
• only small amount of viral material needs to be injected (replicates in body), less virus reduces risk of allergic and injection site rx
• newer vaccines achieve long lasting antibody after single dose
• no adjuvent
• can be given other routes
• cost less

• poorer, shorter-duration cell mediated and humoral immunity
• greater risk of allergic rx and injection site rx
• some not safe for pregnant
• min 2 doses (mostly)
• more expensive

• Must be stored carefully or dies/becomes ineffective
• potential to cause disease in immunocompromised or pregnant animals
• some cause severe complications
• wrong route can cause cause severe illness
• causes relative immunosuppression
• shelf life shorter (no preservatives)

• USDA recognizes 3 categories
• 1. inactivated recombinant organisms or purified antigens derived from such organisms (subunit vaccine)
• 2. live organisms with deleted genes (gene deleted vaccine)
• 3. live vectors with foreign gene insert (live virus vectored vaccine)

• connects two different DNA segments
• inserts gene of interest into vector like bacterial plasmid. Vector cloned and put into mammalian, yeast or special bacteria host. Host cell makes protein, can be isolated and used to make vaccine.

a vaccine that uses merely one component of an infectious agent, rather than the whole, to stimulate an immune response

• contains only proteins that stim immune system to attack, so not infectious and safe for immunocompromised
• reduce amt of antigen due to elimination of irrelevant antigens

• does not stim immune system as well as whole organism vaccines
• many need adjuvent to increase effectiveness

vaccine produced from organisms that have been altered to either delete or inactivate a gene (new form of attenuation)

• safer live vaccine
• often delivered via natural route of infection (mucosal route)
• can be used as marker vaccine (absence of specific antigens from the virus can be used to differentiate between vaccine virus and natural "wild-type" virus

• potential exists for virus to revert to original virulent state
• degree of protection could be limited since immune response is restricted to antigens present on the virus

potential for reduced immune response because vaccine is using only specific protective proteins (Merial Purevax recombinant FeLV Vaccine (no adjuvent))

Vaccine composed of naked DNA (no proteins, no vector virus) that is injected into host.  DNA is taken into host cells and proteins coded by DNA are produced, create immune response.

• reduce vx rx
• easier to make/store
• potential of overcoming maternal antibody interference
• increased duration of immunity

• limited to protein immunogens (no good for non-protein based antigens like bacterial polysaccharides)
• potential for atypical processing of bacterial or parasite proteins

• inactivated, killed, dead, subunit, plasmid DNA, avenomous
• 2 doses (2-6weeks), parental, one transdermal, no replication, 3+ weeks until immune, 1-3 year duration, needs booster, adjuvent usu. required, not in pregnant, great stability

• attenuated, avirulent, modified live, recombinant viral vectored
• 1 dose adequate, multiple routes, no transdermal, replicates in host, immunity in a few days (faster), duration longer (years to life), no adjuvent, not for pregnant, reconstituted not stable (1 hour after), lyophilized stable.

• viral
• bacterial
• parasitic (protozoal, helminth/ectoparasite)

• suspension of killed or attenuated bacteria for use as a vaccine
• less effective than viral
• partial, short-lived immunity
• higher incidence of rx than viral

• live protozoal attenuated vaccine and killed/subunit protozoal vaccine (coccidia, babesia)
• Farm animals, some canine
• no longer made due to limited use

• allergy vaccine
• cancer vaccine (melanoma)

• vaccine against reproductive hormones
• vaccine against gamete antigen (sperm and oocyte antigens)
• vaccines to increase fertility

• "vaccine" using a bacterial toxin that has been treated to destroy its toxicity but still produces an antibody response when injected into an animal
• protection against toxin without live organism (safer)
• shorter duration of effectiveness (may have adjuvent)

• not vaccines, antibodies against specific toxins which have been harvested from immune system of another animal.  Antitoxins are used to reduce the level and damage caused by the release of the bacterial toxin
• quick protection against toxin, but short-lived, may have preservatives

better protection against respiratory viral and bacterial infections, faster, single dose required, rx rare, works while maternal antibodies are present

aerosolized vaccine particles that are forced at high pressure through the skin with an insturment, avoids risk of conventional needle-administered vax and vax-associated inflammation (melanoma)

• designed to immunize against a single antigen or single microorganism
• can select only desired antigen to administer (avoid previous rx)
• more injections necessary so more protein and adjuvent, increases adverse

• immunize against two or more strains of same microorganism, or against two or more microorganisms
• convenient, fewer injections, less expensive
• rate adverse rx increases as the number of antigens increases

• FVRCP SQ lat right forelimb below elbow
• rabies SQ lat right hind limb below stifle
• FeLV, FIV SQ lat left hind limb below stifle

• recommended for all cats and dogs
• feline herpesvirus, feline calicivirus, feline panleukopenia (feline parvo - FPV)
• canine parvovirus, canine distemper virus, canine adenovirus-2 (infectious hepatitis), canine rabies

• vaccine administered to cats and dogs in a certain risk group
• cats: feline leukemia virus (FeLV) vaccine, Feline Immunodeficiency virus (FIV) vaccine, Chlamydophila felis, bordetella bronchiseptica
• dogs: distemper measles virus, canine parainfluenza virus, bordetella bronchiseptica vaccines, borrelia burgdorferi vaccine, leptospirosa 4-way vaccine

• advisory panel believes these vaccines have little or no indication
• not been found to induce clinically meaningful immune response in most cats, may have high adverse
• Feline Infectious Peritonitis (FIP) vaccine
• leptospirosa interrogans (2-way), canine coronavirus, canine adenovirus-1

common viral respiratory disease.  Sneezing, nasal d/c, rhinitis, conjunctivitis, affects reproductive tract, complications in pregnancy

• common viral disease
• URI signs, pneumonia, oral ulceration, occasionally arthritis

extremely contagious virus of the parvovirus group causing disease with severe vomiting, high fever, anorexia, lethargy, diarrhea (often bloody), seizure and high mortality rate

• fatal virus infection attacking CNS
• vaccination is core by law

viral disease in dogs characterized by loss of appetite, catarrhal nasal and ocular discharge, fever, lethargy, vomiting, neurologic signs and death

• highly contagious, often fatal viral disease of dogs, affecting intestinal tract or cardiac system.
• vomiting, severe often blood diarrhea, depression, high fever, loss of appetite

Cav-2 causes infectious tracheobronchitis (kennel cough) but vaccine also protects against CAV-1 which causes cough, pneumonia, liver and kidney failure (canine hepatitis)

• canine H3N8 virus (canine influenza virus, CIV), new influenza in dogs
• flu-like symptoms: c/s, nasal d/c, pneumonia, death.  Killed virus vaccine, SQ, .

• 1. Transient lethargy
• 2. injection site rx (pruritus, swelling, abscess, granuloma, sarcoma, pain, alopecia
• 3. systemic rx (anaphylaxis, angioedema, hives, vomiting +/- diarrhea, fever, lethargy, neuro/behavioral, immune disorder like IMHA, IMT, polyarthritis, glomerulonephritis)
• 4. death
• 5. live IN vx cause mild signs of dz they are preventing