The United States Department of Agriculture has announced that it has four vaccines against highly-pathogenic avian influenza under review.
The virus has forced depopulation of dozens of commercial poultry operations and disrupted business with quarantine zones in both Canada and the United States over the last year.
It has been shed by migrating birds whose dung sticks on boots and is carried into poultry barns.
The vaccines under evaluation have been generated by Zoetis, Merck and two in U.S. Department of Agriculture research labs.
