Whether to implement a vaccination strategy against avian influenza in commercial poultry is a contentious issue in the U.S. An avian influenza killed vaccine for chickens manufactured by Zoetis received conditional approval from the U.S. Department of Agriculture (USDA) Center for Veterinary Biologics (CVB) on February 14.
A conditional license is valid for a finite period and used to meet an emergency condition, limited market, local situation or other special circumstance. The vaccine must still receive final approval from USDA before it can be used in commercial poultry