Vaccines and diagnostics - companion animals and horses Flashcards
Describe an ideal vaccine
- protection against all strain
- prevents infection and shedding
- provides rapid and long lived immunity after single dose
- induces immunological memory so minimal boosters required
Outline passive immunisation
= administering Ab
- natural via colostrum
- administration of antiserum
Describe active immunisation
= administration of Ag + adjuvant
- MLV
- killed
- toxoids
- subunit
- recombinant
Outline vaccine delivery
- most systemic (SC, IM, ID) –> good systemic immunity
- altering route can influence immune response (IN much better at generating IgA response for mucosal protection)
Outline vaccin eprotocls
- primary courses often to young animals (MDA interference, can persist for 12-14 weeks, after this generally MLV only require single dose, inactivated/subunit require at least 2 doses, 2-3 weeks apart, booster q6mo-3 years depending on manufacturer)
Describe vaccination of dogs/cats
WSAVA GUIDELINES
- core (recommended) and non-core (risk assessed)
- dog core DHP (rabies if endemic), non-core: L, Pi
- cat core CHP (rabies if endemic), non-core FeLV
- primary course at 8, 12 adn 16 weeks
- post-vaccine serology recommened in dogs
- booster at 1 yo
- boost no more frequently than 3y intervals
- serology in dogs to determine if booster required?
- these recommendations can conflict with datasheet (8, 10 wk primary course but may cause more vaccine failures)
T/F: immunologically speaking, you don’t need to start the primary course again if booster lapses
True
T/F: there is a therapeutic DNA vaccine (human tyrosinase) for tx of canine malignant melanoma
True
Adverse effects - vaccination
- rare
- often mild (1 in 10,000)
- transient pyrexia and lethargy
- allergic reactions (IgE mediated): facial pruritus and oedema
- link b.w some adjuvanted vaccines (FeLV and rabies) and FISS
- non-adjuvanted vaccines (canarypox vector) available to avoid this
Name 2 vaccines of rabbites
- myxomatosis
- viral haemorrhagic disease
Outline vaccination of horses
PASSIVE IMMUNISATION: - hyperimmune equine plasma for FPT - tetanus antitoxin - rotavirus of pregnant mare for MDA transfer to foal ACTIVE IMMUNISATION: - equine influenza - tetanus toxoid (immediate protection) - EHV-1, EHV-4 - others: WNV, EVA, strangles
What is a new companion animal vaccine protocol?
- 1st dose at 6-8wks
- 2nd dose at 9-10 wks
- MDA interference at this younger age increases risk failure
- allows earlier socialisation
- ideally 3rd dose at 16 wks
What is CaniLeish?
- Leishmania infantum
- PETS
- 3 doses as primary course
- boost annually
- 4 times reduced risk of infection
Reasons for vaccine failure
- strains/serotype in vaccine don’t protect against that in population (feline calicivirus, Leptospira serovars)
- vaccine not stored properly or expired
- vaccine not administered properly
- animal too young/old –> immature/senescent immune system
- interference by MDA
- prior exposure to pathogen (FeLV, herpes)
- animal immunosuppressed / immunocompromised
- animal genetically programmed to generate inappropriate response (e.g. MHC genes in rottweilers may predispose to vaccine failure)
What feline vaccines are available in the USA?
- FIV vaccine (Fel-O-Vax): 2 FIV strains but 70% effective at preventing infection
- ‘FIP’ vaccine: given IN for IgA against enteric coronavirus (which causes FIP), protect against initial infection to prevent persistence and mutation, kittens often exposed before vaccination