Routes of administration are defined by the manufacturer for each immunobiologic. To avoid unnecessary local or systemic effects and to ensure optimal efficacy, the practitioner should not deviate from the routes stipulated by the manufacturer. Injectable immunobiologics should be administered where there is little likelihood of local, neural, vascular, or tissue injury. If more than one vaccine preparation is administered simultaneously, it is preferable to administer each product at a different site. Since the dose of vaccine required to induce an immune response is a species characteristic, the use of partial doses of vaccines is not recommended, even for small patients. Any vaccination using less than the standard dose, a non-standard route, or a non-standard site of administration should not be considered efficacious. The cat should be re-vaccinated according to recognized vaccine protocols established in this document. A recognized exception to this statement is the use of fractional doses of intranasal MLV FHV-1/FCV vaccine in very young kittens.

All biological products are adversely affected by environmental conditions outside those conditions stated on the package insert. Vaccines can be rendered ineffective by heat and freezing. Vaccine products should not be mixed together in the same syringe unless recommended by the vaccine manufacturer.

* All vaccines should be maintained at the recommended temperature from the time they leave the manufacturer until they are administered to the animal.

* All vaccines should be protected against exposure to ultraviolet light.

* The diluent provided by the manufacturer has been pH-adjusted for a particular organism. Therefore, practitioners should never use a diluent intended for a different vaccine to rehydrate a lyophilized product -- even a diluent from the same manufacturer.

* Because different vaccines require different pH values and may have various activating agents or adjuvants that can affect the pH, practitioners should never mix vaccine products unless it is recommended by the manufacturer.

* Attenuated vaccines should be used soon after they have been reconstituted. Therefore, practitioners should ensure that the vaccines are not stored for use at a later date.

* Chemically sterilized syringes should not be used because traces of disinfectant can inactivate attenuated vaccines.

* Before administering any vaccine, practitioners should properly restrain the animal and ensure that the injection site has been cleansed [of debris].*

Larson, Robert L. and Bradley, John S. Immunologic Principles and Immunization Strategy. The Compendium of Continuing Education, Vol. 18, No.9. September 1996 pg.969, with permission.

*Additions added by panel, with permission.

Use of multiple dose vials is discouraged, since inadequate mixing may result in unequal distribution of antigens and adjuvant. In addition, unless multi-dose vials are consumed when first opened, iatrogenic contamination is a significant risk.

Vaccine site recommendations should be followed in accordance with those established by the AAFP and the Vaccine-Associated Feline Sarcoma Task Force (see Appendix B). It is important to standardize vaccine sites to help identify causes of local adverse reactions. Placement of parenteral vaccines in the extremities may also aid in treatment of vaccine-associated sarcomas.

In the event of limb loss from causes unassociated with vaccines, or when it is inadvisable to discontinue parenteral vaccine(s), administration in the remnant of the amputated leg should be considered.

When administered according to the manufacturer's recommendations, similar antigen feline vaccines from different manufacturers may be used interchangeably. These vaccines may be single antigens or combinations of antigens. Although there are limited scientific studies available to support this conclusion, temporal patterns of immunologic response in both kittens and adult cats suggest that a satisfactory immune response is achieved.

The label recommendations found on biological products are the result of the data collected during the approval of the vaccine as interpreted by the manufacturer and the USDA. There is currently a strict USDA requirement for the approval of new novel products that all label recommendations will be precisely supported by data collected during the approval process. Although label recommendations reflect that data, they may or may not represent the optimal way to use a product in clinical practice. In addition, manufacturers may not take into consideration other information (i.e. from an independent investigator) when they create a label recommendation. The AAFP/AFM Vaccination Panel (and practicing veterinarians) have more freedom to evaluate all available data to guide creation of recommendations. Wherever the panel's recommendations differ from the USDA approved label directions, these differences are well supported by applicable scientific principles.

Administering vaccines at intervals more frequently than that recommended by the manufacturer is neither endorsed nor recommended. Administration of vaccines at intervals more frequently than 21 days may result in attenuated immunologic responses.