9a. Vaccine use in Companion Animals in New Zealand

Companion Animal Society of the NZVA Policy Statement

Policy

Veterinarians should maintain a professional approach to all aspects of the use of vaccines. This includes encouraging widespread vaccination as an important means of preventing and controlling infectious diseases while ensuring that vaccines are not used unnecessarily.  Veterinarians should aim to maintain the profession as the source of informed knowledge on the use of vaccines and be responsible for the correct use of these agents.

Veterinarians should only administer vaccine to an animal following a thorough examination to ensure the animal is in good health.  The decision to vaccinate against a particular disease should be based on a risk-benefit analysis that includes consideration of the prevalence and severity of the disease, lifestyle of an individual animal and the efficacy and safety profile of the vaccine.

Veterinarians should adhere to their ethical and legal obligations by informing their clients of the risks and benefits of vaccination of companion animals, keeping comprehensive patient records and vaccination certificates. 

Explanation

The Companion Animal Society (CAS) of the New Zealand Veterinary Association has considered the current available scientific information, the ethical and legal obligations of veterinarians, together with the diseases and vaccines present in New Zealand in forming this public policy statement.

Recommendations for annual revaccination of dogs and cats date back to the late 1950s and early 1960s based on a very small number of early studies and papers, and this became the accepted norm.  While the incidence of serious adverse events following vaccination is considered to be very rare, there is some concern about the possible association of some disorders with vaccination, raising questions about the frequency of revaccination. Increasing scientific information suggests the duration of immunity provided by some vaccines is significantly longer than one year, allowing for less frequent vaccinations.

Over the past 10 years there have been some major changes worldwide in how veterinarians view vaccines and vaccination practices.  These include the concept of core and non-core vaccines, disease risk assessment, extended revaccination intervals, and using products that minimise the risk of adverse events.

Vaccine manufacturers’ recommended protocols on labels provide guidelines. Selection of an actual vaccination protocol recommended by the veterinarian for a particular cat or dog should be based on knowledge of the patient’s age and lifestyle, the vaccine manufacturers’ recommendations and their supporting product data, scientific literature, an understanding of immunology and knowledge of local disease risks.    Variations in veterinarians’ vaccine recommendations may be confusing for some pet owners and boarding facilities. Open communication and education will be important in facilitating understanding.  As more scientific information becomes available over the years to come there will undoubtedly be further changes in vaccination practice.  

Recent publications such as the 2006 American Association of Feline Practitioners Feline Vaccine Advisory Report, (AAFP) The World Small Animal Veterinary Association Vaccination Guideline Group  2007 report (WSAVA VGG) and the American Animal Hospital Association 2006 Canine Vaccine Guidelines (AAHA CVG ) reflect a combination of expert opinion, personal experience, and scientific studies published and unpublished.  They strive to give general vaccination guidelines to cover world wide variation in vaccine products, individuals administering those vaccines and animal population and disease dynamics.  They do not represent a vaccination protocol nor vaccination standards but are intended as a guideline to help veterinarians make practical recommendations for their own patients. These publications are listed at the end of this policy.

Taking the New Zealand vaccination environment into consideration, the Companion Animal Society of the NZVA has incorporated recommendations from the above publications in the following guidelines where appropriate.  CAS will continue to regularly review the scientific literature regarding companion animal vaccines and communicate with the membership should this information lead to changes in this vaccination policy.

Guidelines

1. Veterinarians should perform a consultation and thorough examination prior to the use of any vaccine.  Where possible only healthy animals with normal temperatures should be vaccinated.
2. Vaccination should be tailored to the needs of the individual animal and each case should be individually assessed. This includes a risk assessment for inclusion or exclusion of non-core vaccines and consideration of scientific knowledge regarding extended revaccination intervals. Annual health check visits should be encouraged to provide for comprehensive individual care beyond vaccination.
3. Vaccines must be stored and handled according to manufacturers’ recommendation.

• Vaccinations should be stored in the middle compartment of the fridge - at 2-8 degrees Celsius at all times, unless otherwise specified by the manufacturer.  I.e. do not store in the door or near the freezer compartments. (See NZVA Policy on Storage of Animal Remedies.)
• A full vaccine dose must be used in each individual animal regardless of its body weight. Vaccine   doses must not be split between two or more animals.

• Always follow the vaccine manufacturer’s guidelines when preparing vaccines
• If a vaccine is spilled, clean the vaccine off the animal’s fur with alcohol swabs and use a virucidal agent at the recommended dilution for efficacy against viruses on any contaminated surfaces.
• Veterinarians must be aware of potential adverse events due to vaccines, their detection and treatment.  The risk of adverse events should be discussed with the pet owner prior to administration. Clients should be advised to monitor their pets including vaccination site(s) and to contact the practitioner in the event of any abnormalities. Any adverse reactions must be reported to the ACVM Group of the New Zealand Food Safety Authority and/or to the vaccine manufacturer (or its agent).
• Feline Immunodeficiency Virus vaccination induces serum antibodies which may interfere with in-clinic antibody testing and therefore determination of a negative serological status of cats prior to starting the initial course of vaccines is recommended.
• Although the risk of vaccine associated sarcoma (VAS) in cats is low, to facilitate treatment should the need arise,  non-adjuvanted (including live) vaccines should be administered subcutaneously laterally over the shoulder, being careful to avoid the midline or inter-scapular space and adjuvanted killed vaccines subcutaneously on the lateral side of the hind limb as distally as possible. These recommendations should be followed as far as is practicable and it is recommended that the                                                        anatomical location of the vaccination site is noted in clinic records. (See below for further discussion on injection site sarcomas (ISS) in cats).
• The veterinarian must keep a permanent record in the medical record for the animal of the batch number and expiry date of each vaccine administered and any owner discussions regarding the use of the vaccine in addition to all details required on a vaccination certificate. Every animal that is vaccinated must be adequately identified as an individual in the clinic’s records.
• The veterinarian shall offer the current owner (breeder, SPCA or other agency if the animal is intended for sale or re-homing) a clear certificate or record of each vaccine administered and the animal to which it was administered.  The record shall include:
  
  1. the name and address of the practice
  2. the name and qualifications of the veterinarian
  3. the name of the current owner
  4. accurate identification of the animal being vaccinated, including description of species, breed, colour, age, sex and microchip number if applicable.
  5. the date of vaccination
  6. the vaccine type and trade name, batch number and expiry date 
  7. the recommended date(s) for re-vaccination
  8. signature of the administering veterinarian – to be done ONLY after all the above information has been completed.

Certification may be wholly or partially provided by a computer generated form that contains all the information specified above, as long as it is signed by the veterinarian. If at a later date the original certificate has to be replaced, a copy or replacement certificate may be issued but must be clearly marked as “COPY” or “DUPLICATE” or “REPLACEMENT”. If the original veterinarian is unable to sign such a replacement certificate, then the words “according to our records” and a signature of a verifying veterinarian will be sufficient for certification.

References

2006 AAHA Canine Vaccine Guidelines, Revised, (www.aahavet.org).

American Animal Hospital Association (AAFP) Feline Vaccine Advisory Panel Report. Journal of the American Veterinary Medical Association 229, 1405-1441, 2006.

Guidelines for the Vaccination of Dogs and Cats, Compiled by the vaccination guidelines group (VGG) of the World Small Animal Veterinary Association (WSAVA). Journal of Small Animal Practice, 2007.

European Advisory Board on Cat Diseases (ABCD), ABCD guidelines on Feline Calicivirus, March 2007, ABCD guidelines on Feline Herpes Virus 1, Oct 2006, ABCD guidelines on Feline Leukaemia Virus, Oct 2007. (www.abcd-vets.org).

2006 Canine and Feline Vaccination Guidelines: A Forum on Issues and Controversies, Dr Richard Ford, North Carolina State University (www.hcvma.org/notes/SpeakerNotesRichardFord.pdf)

Comparison of the histology and immunohistochemistry of vaccination-site and non-vaccination-site sarcomas from cats in New Zealand.  D. Aberdein[1] et al, New Zealand Veterinary Journal 55(5), 203-207, 2007. 

Summary of SOME of the issues and recommendations discussed by individuals associated with the development of the vaccination guidelines for WSAVA, AAHA and AAFP:

• Aim for population immunity – vaccinate the greatest number of animals possible to reduce the prevalence of disease for the population.
• Reduce the frequency of vaccine administration to any individual animal to reduce the potential for side effects.
• Administer ‘core’ vaccines to all puppies & kittens and ‘non-core’ vaccines according to individual risk / benefit assessment only. Vaccines available in NZ are:

      Dogs                                           Cats    

     Core vaccines:            Canine Distemper Virus          Feline Panleukopaenia Virus

            Canine Parvovirus                   Feline Herpevirus

            Canine Adenovirus                  Feline Calicivirus

            Non-core vaccines:     Bordatella bronchiseptica        Chlamydophila felis (Chlamydia)

                                                Canine Parainfluenza Virus     Feline Immunodeficiency Virus

                                                Leptospirosis                            Feline Leukaemia Virus

                                                Rabies Virus                             Rabies Virus                     

                                                Canine Coronavirus             

• The duration of immunity (DOI) of vaccines vary. Scientific evidence suggests vaccination with Modified Live Virus (MLV) core vaccines gives protection for much longer than one year. Many core vaccines are licensed for and have a recommended duration of immunity of three years. With some core vaccines the duration of immunity is likely to be longer than three years. Killed vaccines in general have a much shorter DOI compared to MLV vaccines.
• Many ‘non-core’ vaccines are bacterins. These may not provide protection beyond one year.
• For some diseases humoral antibody level in response to vaccination correlates well with protective immunity. However, low titres do not necessarily correspond to susceptibility and in some diseases cell-mediated immunity may play a more important role in clinical protection. (In NZ the practice of obtaining titres for individual disease risk assessments is not practical at this time).
• Both dogs and cats are most susceptible to infectious diseases when young and vaccination at this age is extremely important.
• Puppy and kitten primary vaccination series:
  • Maternally derived antibodies (MDA):
    • Presence of maternal antibodies can interfere with the response to vaccination.
    • The age at which a puppy or kitten is no longer protected by maternally derived antibodies (MDA) varies with the individual puppy or kitten and the level of maternal immunity received.  Some individuals may have little or no MDA protection from birth, while  others may still be have some MDA at 16 weeks of age or older. Most puppies and kittens will have inadequate MDA for protection from disease by 8 – 12 weeks of age.
    • A general guideline is to start vaccinations at 8-9 weeks and administer a course of 2-3 injections ending at 12- 16 weeks of age. (Vaccines may vary in their ability to overcome MDA and patients with suspected low MDA or at high risk should be started as early as possible according to specific vaccine).
  • A final vaccine at 16 weeks of age should be considered to ensure optimal efficacy in high risk situations.
  • Poor or non-responders - a small percentage of animals will require a greater number of vaccines or may never respond. 
  • If MLV vaccines are used, once interference from MDA is no longer an issue, cats and dogs generally require only a single initial vaccination.  If there is adequate response the protection from this one vaccination can last at least 3 years. 
• A booster administered 12 months after the primary course helps to ensure adequate vaccine-induced immunity for cats and dogs that may not have adequately responded to the primary course. 
• Injection Site Sarcoma (ISS) / Vaccine Associated Sarcoma (VAS)
• Cats can develop injection site sarcomas (ISS) to antibiotics, vaccines and other types of injections and some killed adjuvanted vaccines have been implicated in particular with vaccine associated sarcomas (VAS). The recognition of even a low risk for cats has been the driving force behind the change in recommendations worldwide in the frequency of vaccine administration and injection sites. To further reduce the risk and to aid the management of VAS some suggestions have been given by experts:
  • Reduce the overall number of vaccines administered
  • Reduce the number of injections given in the inter-scapular region in cats. To aid in the management of VAS should it occur (i.e. to allow for distal limb amputation). Administer non-adjuvanted vaccines subcutaneously on the lateral side of the forelimb as distally as possible. Administer killed vaccines subcutaneously on the lateral side of the hind limb as distally as possible. In New Zealand where Rabies is not a core vaccine, use the hind limbs alternately for administration of adjuvanted vaccines.
• Disease control in specific situations such as shelters requires special consideration and the 2006 AAHA Canine Vaccine Guidelines, Revised publication provides recommendations (www.aahanet.org).

Policy Files: 

9a - Vaccine Use - Jan09.pdf