The Government of Canada has secured an initial supply of 500,000 doses of GSK's bird flu vaccine to protect individuals most at risk of being exposed to the virus through animals infected with avian influenza.

The Public Health Agency of Canada said Wednesday it's purchased 500,000 doses of a human vaccine to protect against avian influenza to protect people most at risk from being exposed to the virus by infected animals.

In other avian flu developments, tests at the US Department of Agriculture (USDA) have confirmed the H5N1 strain in rats for the first time, as the agency acknowledged that it was reversing recent layoffs of employees working on the avian flu response.