The US may start vaccinating chickens and cows against bird flu

As farmers across the US struggle to contain a deadly bird flu virus, the US Department of Agriculture (USDA) is considering adding animal vaccines to its strategy for controlling the outbreak.

Until now, vaccination was largely off the table given some countries restrict trade on inoculated birds. This includes Canada, one of the largest importers of US poultry products. The concern is that vaccinated flocks can harbour residual amounts of the virus,…