Regulatory Brief

 Vaccine Mixing

Brief Description:

In April 2011, the U. S. Department of Agriculture (USDA) Center for Veterinary Biologics (CVB) alerted the AVMA to an improper vaccine practice by some veterinarians. Specifically, the CVB shared its concerns that rabies vaccine was being used as an off-label diluent for canine or feline distemper vaccine reconstitution. Such improper vaccine mixing is not consistent with CVB regulations and manufacturer label recommendations. The CVB sought support from the AVMA to help ensure that veterinarians follow the label when using vaccines.

AVMA Response:

AVMA agrees with CVB that improper mixing is dangerous and inappropriate. The AVMA further recognizes that such practices can cause negative effects on product performance including: decreased or no efficacy of the mixed vaccines, increased adverse events including injection site reactions and systemic reactions, potential toxin overload from vaccine adjuvants, potential toxemia from inappropriate mixtures of products, and changes in withdrawal interval times following vaccination of food animals.

The AVMA sincerely appreciates the CVB's swift communication regarding if/when concerns are detected. Through several communication vehicles, the AVMA is able to work promptly to educate and remind our more than 81,500 members of the federal regulations and best practices to follow when using veterinary biologics in clinical practice.

The AVMA welcomes the opportunity for continued dialog to further determine ways forward to promote best practices for veterinary vaccine use.

Background Documents:

The AVMA responded on July 25, 2011 (PDF)