Exam 4: Dr. Sullivant Vaccine Immunology Flashcards
Describe passive immunization
Transfer of ready-made antibodies to an individual
Provides immediate humoral protection
Does not induce an immune response from the host (no memory)
What are clinical examples of passive immunization?
Rabies post-exposure prophylaxis in humans
Tetanus antitoxin
Pit viper antivenin
Plasma transfusions
What are the methods of passive immunization via transfer of maternal antibodies?
Passive transfer of maternal antibody through placenta
Ingestion of colostrum via initial suckling
What happens with the GI tract with suckling to get colostrum?
It has maximal permeability to proteins from 0-4 hours, closes by approximately 24 hours
What is the pro of passive immunization via transfer of maternal antibodies?
Provides immediate protection of the neonate against pathogens and lasts for 6-16 weeks of age, on average
What is the con of passive immunization via transfer of maternal antibodies?
Can interfere with vaccination of neonate via binding of maternal antibody to the antigen in the vaccine (known as immunity gap)
What is the strategy of passive immunization via transfer of maternal antibodies?
Administer multiple, sequential vaccines to puppies and kittens until at least 16 weeks of age
- -1st vaccine: initial response/recognition takes 10-14 days with maximum response at 3 weeks
- -2nd vaccine: leads to immunological memory
- -3rd and 4th vaccine: stronger and more rapid memory
What is the immunity gap?
Maternal Ab can do this even when the level of antibodies is not sufficient to protect against pathogens
Vulnerable window of time where there is a little too much of the mother’s antibodies
What are the different types of vaccines?
Killed
Modified-live
What are killed vaccines?
Organism is completely inactivated
May require adjuvant to stimulate immune system
What is modified-live vaccine?
Organism is modified to a less virulent state (attenuated)
What are the pros of MLV?
Rapid and prolonged protection Stimulates CMI and long-lived humoral immune response Reduced allergenicity Stimulates secretory antibody Lower antigen mass needed Single dose effectiveness
What are the cons of MLV?
No preservatives for storage Requires multiplication in host Susceptible to inactivation Risk of reversion to virulence Can produce vaccine-induced illness in immunosuppressed hosts Vaccinates can shed into environment
What are the pros to killed vaccines?
No reversion to virulence Stability in storage Increased immunity with added adjuvants Safe in immunosuppressed animals Vaccinates do not shed organisms
What are the cons to killed vaccines?
Stimulates humoral immunity Minimum of 2 doses needed for protection Increased risk of allergic complications Shorter duration of immunity Adjuvants frequently required* Ag may not induce proper Ab if too denatured
What are adjuvants?
Substance that enhance the immunogenicity of vaccines that stimulate cell-mediated immunity
What are adjuvants used with?
Killed organisms or purified antigens
What do adjuvants attempt to do?
Increase duration and amount of immuno-stimulation equal to MLVs
What do adjuvants produce?
Heightened inflammatory reaction–good or bad
What is the underlying theme of sarcoma development in cats?
Inflammation
Where is the rabies vaccine site?
As low as possible on the lateral right hindlimb (below stifle)
Where is the FeLV vaccine site?
As low as possible on the lateral left hindlimb (below stifle)
Where is the FPC/FHV-1/FCV vaccine site?
Lateral aspect of right forelimb below elbow
When are core vaccines used?
Infection has high risk of morbidity and mortality
Infections are of public health concern
Infections are readily transmitted
Infections are ubiquitous in environment
Safe, efficacious vaccines are available
Vaccines prevent infection or decrease clinical signs
What are examples of canine core vaccines?
DA2P (distemper, adenovirus, and parvovirus)
Rabies
What are non-core vaccines used for?
Vaccine may have limited efficacy
Disease is not readily transmitted
Limited geographic disturbance or prevalence
Disease is mild
Vaccines may interfere with diagnostic screening
What are examples of canine non-core vaccines?
Leptospirosis
Bordetella
What are examples of feline core vaccines?
FVRCP (Feline viral rhinotracheitis, calicivirus, and panleukopenia)
Rabies
Feline leukemia virus
What are the recommendations for feline viral rhinotracheitis?
Cats can persistently shed virus Prevention before exposure is key MLV or killed vaccine at 6-9 weeks old (right front) Kittens need 2nd vaccine 4 weeks later Last vaccine at 16-20 weeks old Vaccinate 1 year later Then every 3 years
What are the recommendations for feline rabies?
Initial vaccine at 12 weeks with recombination vaccine or killed
Distal right hindlimb
Give recombinant vaccine annually
Check state and local regulations
What are the recommendations for FeLV?
Recommended to vaccinate when less than 1 year and booster in 1 year
Viral screening of all kittens with ELISA prior to vaccination
Use killed or recombinant vaccine at 1st or 2nd kitten visit
Then 4 weeks later
Then 1 year after last kitten vaccine
Left hind limb
Becomes non-core vaccine for adult cats
What are the feline non-core vaccines?
Chlamydiosis
Bordetella
What is a feline vaccine that is not recommended?
Feline immunodeficiency virus
What is used for the diagnosis of feline immunodeficiency virus?
SNAP test is used for antibodies to FIV, so vaccinated animals are positive
What happens when vaccinating older animals?
Can mount an adequate immune response
2 vaccination given 3-4 weeks apart are considered protective in dogs and cats older than 16 weeks
One MLV would likely also be protective
Booster at 1 year for first vaccination, then every 3 years
Duration of immunity has been shown to be up to more than 5 years for many core products
What is an adverse reactions for cats?
Feline injection site sarcomas
How can you protect from adverse reactions?
Avoid adjuvants
3-2-1 rule
What is the 3-2-1 rule?
Persists for longer than 3 months
Greater than or equal to 2 cm
Increases in size after 1 month
