Vaccination principles

The use of vaccines has been proven to be highly efficacious and beneficial to the health of veterinary patients, as well as the general public. Historically, vaccination has dramatically reduced the incidence of infectious disease and has helped to eradicate it. Decisions concerning individual vaccines and vaccine programs are best made within veterinarian-client-patient relationships. Best practices suggest veterinarians should create a core vaccine program intended for use in the majority of animals in their practice area, as well as a non-core vaccine program that is based on assessment of individual patients. Veterinarians should remain up to date on new commercial offerings, as well as procedures for reporting adverse events. Vaccine programs should follow all governmental regulations. The AVMA advocates a medically based approach to vaccination based on the preventive health needs of individual patients or populations and national animal health programs.

To assist in developing a vaccine program, multiple sources of information are available, including species and specialty groups, manufacturers' package inserts, and government agencies, such as the USDA's Center for Veterinary Biologics. The AVMA continues to advocate for increased availability of animal vaccines that are safe, efficacious, scientifically-based, and clinically practical, to provide practitioners with a basis for developing optimal vaccine programs.

Vaccine programs should be designed to maintain the health of the animals and protect public health, while minimizing adverse effects. Veterinarians should evaluate the risk/benefit ratio before vaccinating a patient, taking into account the general health and history of the patient, therapeutic interventions and management practices that may affect administration or effect of the vaccine, the vaccine antigen/adjuvant combination, route of administration, population immunity and public health concerns. While vaccine safety is tested by vaccine companies prior to licensing for general use, individual adverse reactions can and do occur. This is generally a small percentage of the vaccinated population, and the benefits of vaccination have been shown to far outweigh the risks.

Vaccine efficacy and duration of immunity are highly dependent upon the type of vaccine (e.g., modified live, killed, recombinant/vectored), the individual patient's health, method of administration, age, genetics, and species being vaccinated, as well as management factors such as nutritional status, stress level, and other potential exposures.

Inducing a protective immune response may require a primary immunization followed by a booster vaccination. In young animals where maternally-derived antibodies are still present, multiple vaccines may be required over a period of several months. Antibody titers or other immunological measurements to determine if booster vaccination is warranted should not be used if standardized tests and protective levels of immunity have not been defined for the disease. Patient disease susceptibility, immune status, and duration of immunity for the vaccine of interest should be balanced when considering the timing of re-vaccination.

Label indications and directions should be followed. Veterinarians may exercise discretionary judgment if medically justified, and in compliance with all applicable governmental restrictions. All manufacturers' information concerning vaccine storage and handling should be followed to help ensure vaccine purity, safety, potency, and efficacy. Failure to administer a vaccine according to the manufacturer's directions (e.g., allowable concurrent treatments, route of administration, approved dose) may result in suboptimal protection and/or adversely alter the established safety profile of the product. All manufacturer cautionary warnings on vaccines should be followed. Veterinarians should recognize that failure to use vaccines according to a manufacturer's label directions may result in potential liability to the veterinarian in the case of an adverse event or lack of efficacy. All adverse events should be reported to the manufacturer to ensure the continued safety and efficacy of veterinary vaccines.