Vaccines pt 2 (feline) Flashcards
core feline vaccination schedule summary
herpesvirus, calicivirus, panleukopenia virus:
- Cats up to 16 weeks old:
> at least 3 doses given every 2-3 weeks. Start at 6 weeks, vaccinate until 16 weeks.
- cats > 16 weeks old:
> 2 doses, given 2-4 weeks apart
- Revaccination: One dose 6 (kitten) to12 months after last dose in initial vaccine series; then every 3 years
Rabies:
- As per local law, given once when cat at least 12 weeks old.
- Revaccination: As per local laws and vaccine label, typically every 1-3 years
revaccination interval change for kittens - what is the new reccomendation and why?
- After the kitten series for FHV/FCV/FPV, revaccination was given 1 year following last dose
- Most recent AAHA / AAFP (2020) guidelines suggest that kittens be revaccinated at 6 months (not 1 year) after the last kitten series dose
> Decrease the susceptibility window if kittens still had maternally derived antibody at 16 weeks of age (last kitten series dose)
> Then you would revaccinate 3 years later
feline panleukopenia: contagious? clinical signs?
- Highly contagious, similar to CPV
> Shed in feces and secretions - Clinical signs due to:
> Bone marrow suppression** - low WBCs
> GI – diarrhea, vomiting
> If pregnant queen infected – abortion or late-term infection will result in kittens with CNS signs (e.g., cerebellar hypoplasia)
feline herpes / caliciviruses - where do they infect / clinical signs?
Primarily upper respiratory tract infections
- Fever, sneezing, conjunctivitis, rhinitis, salivation.
FHV:
- Ocular signs often accompany respiratory signs – conjunctivitis, sometimes keratitis & ulcers
FCV:
- Oral lesions common (ulceration oral +/- nasal surfaces)
- Can also be associated with gingivitis, stomatitis
do indoor cats need a rabies vaccine?
Even indoor cats need a rabies vaccine
- Cats can escape
- Bats can enter the house
non-core feline vaccines
- Feline leukemia virus (FeLV)
> Note: Considered core in kittens - Chlamydophila felis
- Bordetella
what is feline leukemia virus? what animals does it affect? when is it considered a core vaccine vs non-core? transmission?
- Retrovirus affecting cats of any age
- Kittens & young cats most susceptible
- Considered core when <1 year of age due to increased susceptibility - Considered non-core for low risk adult cats
- Transmission through cat-to-cat contact
FELV exposure potential outcomes
Abortive (transient) infection
* Immune system clears FeLV after exposure
Regressive (latent) infection
* Immune response contains but does not eliminate FeLV
* FeLV in cat’s genome
* Low risk of FeLV disease, but could reactivate later in life
Progressive (persistent) infection
* Immune system inadequate or overwhelmed, cannot contain FeLV
* Higher risk of FeLV- associated diseases, shorter lifespan
FeLV-associated conditions include:
- Malignancy (especially lymphoma, leukemias)
- Myelosuppression
- Immunosuppression
- Other conditions
FELV vaccination reccomendation
- AAFP, other experts recommend FeLV vaccination for all kittens up to/including 1 year of age
> Kittens much more susceptible to infection vs. adult cats
> Hard to predict if their ultimate environment (outdoor access) - Adult cats: reassess & continue vaccination if risk persists
FeLV vaccination schedule? what should we establish prior to vaccination?
Initially:
- 2 doses, 3-4 weeks apart after 6 weeks of age
Revaccination:
- 12 months after last dose in series
- Then annually if risk of encountering FeLV+ cats persists
> Risk = outside access, lives with FeLV+ cat, exposure to indoor or outdoor cats of unknown status
> Guidelines suggest revaccination every 2-3 years (based on product label) in cats that are at risk but risk is considered low
- Establish FeLV antigen status prior to vaccinating
what type of pathogens are bordetella and chlamydia in cats? is vaccination usually done? when should it be?
- Respiratory pathogens in cats
- Not routinely administered
- Example of when it is recommended: part of control program in multicat house where specific infection is confirmed
Which feline vaccines are not reccomended? why?
Feline infectious peritonitis
- Coronavirus vaccine
- Uncertain protective benefit; vaccine serotype different from what causes disease
- Most cats are already exposed to coronavirus
> Mutated coronavirus = FIP (vaccine doesn’t appear to prevent mutation)
Feline immunodeficiency virus (FIV)
- No longer available
- Uncertain protective benefit
what the utility of FHV-1 and FCV vaccines in disease prevention / protection? limitations?
- Help reduce severity of these infections, but do not offer complete protection
- Limitations:
> Infections still occur
> Cats can still shed the viruses
most common types of vaccine associated adverse events
- Most common reactions are due to local inflammation at injection site
- Pain at site, general lethargy
- Typically mild, do not require specific treatment
second most common type of vaccine associated adverse reactions? how can this manifest?
- Other reactions are rare, but of these Type 1 Hypersensitivity are most common type
1 to 5 events per 10,000 vaccinations
Can manifest as:
- Skin signs (hyperemia, swelling, pruritus)
- GI signs (vomiting, diarrhea)
- Respiratory signs (dyspnea)
- Collapse
acute management plan for local vaccine reaction?
Local (cutaneous) reactions – minutes to hours post-vaccine:
- Dexamethasone 0.05 to 0.1 mg/kg IV or IM
- Diphenhydramine 2 mg/kg IM (might not be effective once reaction starts)
Monitor for progression to systemic reaction
- Uncommon
acute management plan for a systemic vaccine reaction?
Immediate onset shock / anaphylaxis (marked hypotension):
- Epinephrine 0.01 mg/kg IM or slow IV
- IV fluids
- Vasopressor (e.g., dopamine)
- Bronchodilator in cats (e.g. salbutamol inhaler, terbutaline IM or IV)
three things we must do in the case of of an adverse vaccine reaction
- treat patient as necessary
- document
> describe vaccine event, signs, product
> prominent place in record - report
> to manufacturer (CFIA, USDA)
adverse vaccine rates in cats
- In a study of almost 500,000 cats (1.25M vaccine doses)
> 0.52% rate (51.6 VAAEs/10,000 cats vaccinated) - Most common VAAE was lethargy +/- fever
- Lower rates of vomiting, facial edema, collapse
> 4 cats died (at least 2 had anaphylaxis)
adverse vaccine events rates in dogs
In a study of 1.2M dogs (4.5M vaccine doses)
- 0.38% rate (38 VAAEs/10,000 dogs vaccinated)
- Most common VAAE included facial edema/pruritus
- Lower rates of vomiting, local site reactions
- Lower rates of vomiting, facial edema, collapse
> Collapse in 1%
> Death in 3 dogs (0.024 deaths/10,000 dogs vaccinated)
risk factors for adverse vaccine reactions
- Younger ages
> Up to 1 year in cats; 2 years in dogs - More vaccines per visit (e.g., 3 or more)
- Smaller sized dogs
what are immune mediated adverse vaccine events usually a reaction to?
Often it is an antigen in the vaccine components (not the vaccinal antigen) that is the cause of immune mediated reactions
- Albumin, gelatin, etc
how to mitigate risk of adverse vaccine event?
- Number of separate vaccines given associated with increased risk
> Decrease number of products given
> A combination vaccine would be considered 1 vaccine product in this context - Pretreat with diphenhydramine routinely?
> No proven benefit in general population if no history of vaccine reaction
what should we consider when vaccinating after an adverse event? what if vaccination is deemed necessary?
- Weigh benefits & risks of future vaccines > Consider severity & type of previous adverse event
- Tailor vaccines to individual dog
- Explore if alternatives to vaccination (e.g. serologic testing) are appropriate if reaction was severe
If vaccination deemed necessary, consider:
- Pre-treating with diphenhydramine &/or glucocorticoid
- Using a different product/manufacturer
- Monitoring for several hours in hospital after event
- Giving only 1 vaccine per visit (2 weeks or more between visits)
cause of feline injection site sarcomas? when do they generally appear?
- Any injection = inflammation at site
- FISS have been recognized since 1991
> Appear to be largely associated with vaccines
> Work has been done to identify which vaccines/which vaccine components, but so far unclear
> Possible role of vaccine adjuvants but not clear-cut
> Vaccines are the most commonly implicated injections causing FISS, but has been
reported with others
> Most commonly occur 1-3 years post injection
whats an adjuvant?
- Adjuvants are often added to killed vaccine products
- Can be a chemical, microbial component, or protein that induces an immune response to the vaccine
- Help induce an immune response against the vaccine
- NOTE: Early work suggested adjuvanted vaccines were associated with FISS… now it’s not so clear
FISS prognosis?
FISS are difficult to treat and have a poor prognosis
how can we optimize vaccine protocols to minimize risk of FISS?
- vaccinate on limbs and tail
- individualize vaccine schedule
what type of immune response do vaccines generate?
Vaccines induce cell mediated and humoral immune responses
what is the duration of immunity?
- Length of time the vaccine is effective in mounting a robust immune response / protection
- Many vaccines are labeled to have the minimum DOI
> Often 1 or 3 years
which vaccines are expected to induce short-lived immunologic memory? how often should we revaccinate?
Leptospirosis, Bordetella
- Revaccination yearly is needed to maintain immunity
vaccines with longer immunologic memory and protection?
CDV, CAV, CPV, FPV
where should we look for DOI information?
While DOI often found on label, recommend checking DOI guidelines for the general vaccine type in the AAHA and AAFP guidelines
how have revaccination time intervals changed over the years?
- (Very) old vaccine guidelines suggested annual revaccination for all vaccines
- Previous (relatively small) studies showed antibody titre or protection (challenge study) against CDV, CAV, CPV, FPV challenge 3+ years after vaccination with puppy series
> Led to many core vaccine DOI extended to 3 years
gold standard for serologic testing for presence of antibody against an infectious organism? what other options exist?
- Gold standard test is virus neutralization, performed at specialized laboratories
- Some commercial ELISAs available, often with fairly good correlation to gold standard
> However, variability between tests and laboratories exists
can we look at titers for animals to determine protection against disease?
- A titre test is a dilution of antibody
- Detectable titre indicates a previous vaccination or exposure to infection
- Little to no evidence-based studies indicating what is a “protective” titre level
> Some laboratories / tests will report a protective titre - Vaccine challenge studies are used to show vaccine efficacy but serology has not been paired with most challenge studies
> Challenge studies also use small numbers, lack genetic diversity of populations, and are in a controlled setting
should you offer titer testing? for what diseases if any?
- Consider revaccination with the 3 year intervals for core vaccines as your standard
- In some patients, titres could be an alternative to consider
> History of severe vaccine reaction
> Persisting vaccine hesitancy despite calm educational discussions regarding vaccinations as well as limitations of serology
> Only of use for CDV, CPV, CAV, FPV
serologic testing interpretations
- Positive test: measurable antibody; assumed to reasonably correlates with protection from infection for certain pathogens (CDV, CAV, CPV; FPV)
- Negative test: no measurable antibody
> Could be due to lack of protection following vaccination
> Could also be due to antibody below detectable levels as no recent exposure (but immunologic memory persists).
how do we determine rabies immunity for importation into countries free of terrestrial rabies
rabies serology
law for rabies vaccine administration
The Ontario government has changed Ontario Regulations 567 (Rabies Immunization), came into effect on July 1st, 2023
Immunization against rabies shall be,
a) Carried out by a veterinarian in Canada or the United States of America who is authorized to practice as a veterinarian in the jurisdiction where the vaccine is administered, or by the lawfully authorized delegate of such a veterinarian; and
b) By inoculation with a rabies vaccine that is licensed for use in the jurisdiction where it is administered and that is administered in accordance with the instructions of the manufacturer who produced the vaccine.
Anecdotal concern for some breeds having decreased immunization following routine vaccine series - what breeds?
> Dobermans, Rottweilers
reports of vaccinated dogs developing parvovirus from vaccine later determined to be related to what?
> Previous reports of vaccinated dogs developing parvovirus later determined to be
result of specific lines/genetic defect causing poor vaccine response
Does not appear to be a widespread breed-related problem
vaccine non-responders for what breeds?
Vaccine non-responders exist in multiple breeds but are rare
Hypertrophic osteodystrophy following vaccination in certain breeds – anecdotal reports - what breeds?
Weimaraner, etc
what is HOD? is it related to vaccination? what dogs mostly affected?
- Hypertrophic osteodystrophy following vaccination in certain breeds – anecdotal reports
> E.g., Weimaraner - HOD is a disease of young, rapidly growing dogs with unknown pathogenesis
- Reported in several breeds, likely genetic basis
- Strong heritable component in Weimaraner suspected as sometimes entire litter can be affected
is there strong evidence linking HOD to vaccines? should we use a different protocol for Weimaraners?
- HOD onset and timelines for vaccinating puppies coincide
- Most vaccinated Weimaraners do not develop HOD
- Pathogenesis of HOD unknown, no strong evidence suggesting it is due to vaccine
- Some breeders advocate for recombinant over MLV vaccines
> Reports of dogs that received recombinant vaccines still developing HOD - Guidelines do not suggest using a specific protocol for Weimaraners
when can you not vaccinate?
- If systemic, not stabilized disease at present
> In cases of stable chronic disease (e.g., diabetic) can vaccinate at that time - Receiving immunosuppressive treatments (full dose)
- Another vaccine given very recently
> Vaccines should be 2 or more weeks apart - What about surgery / anesthesia?
> Generally not recommended
> Possible risk of adverse event (e.g., vomiting) that could compromise anaesthetic recovery
> A study from UF showed similar antibody responses in cats vaccinated before, at the same day, or after anesthesia/OHE
can cats with FeLV or FIV be vaccinated? considerations?
- Retrovirus + cats can be vaccinated
> No utility in giving a FELV+ cat an FELV vaccine - Consider giving an inactivated rather than attenuated live vaccine
> Considered safer for immunosuppressed individuals although no cat-based evidence to support this
what do you put into the medical record for vaccination?
- Vaccination is a medical treatment that must be appropriately recorded in the medical record
- For each vaccine, record:
> Types of vaccines administered
> Sites of vaccines administered
> Routes of vaccines administered
> Details (manufacturer and serial numbers) of vaccines administered
> If any reactions are noted - Rabies vaccine certificate is a part of the medical record
