USDA Scientists Weigh Avian Flu Vaccine for Cows; Virus May Be Spreading From Cattle to Poultry

By Lisa Schnirring

In updates to its frequently-asked-question backgrounder on the H5N1 avian flu situation in dairy cows yesterday, the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) provided several updates on the investigation and response, including that its Agricultural Research Service has started to assess the potential to develop an H5N1 vaccine for cows.

The agency added that it's difficult to say how long development might take, because there are still questions about transmission to cattle and characteristics of infection in cows. APHIS said manufacturers have expressed interest in producing vaccines for both poultry and cows.

"We will continue to engage with these developers to better understand their vaccine development, the efficacy of potential vaccines, as well as the cost of development and production," it said.

Among other updates, APHIS said wild migratory birds are still thought to be the original source of the virus, though the investigations have found instances of virus spread linked to cattle movements between herds.

APHIS also noted that there is similar evidence that the virus has spread from dairy herds back into poultry flocks through an unknown route.

Virus hits commercial poultry in another Michigan county

In other developments, the Michigan Department of Agriculture and Rural Development (MDARD) said yesterday that tests have confirmed highly pathogenic avian flu in a commercial poultry facility in Newaygo County, which is located in the west central region not far where outbreaks recently struck dairy facilities and poultry operations. 

MDARD urged producers to protect their animals from wild birds and viruses they may be carrying as the wild birds complete their spring migration.

Recent outbreaks were reported at two massive Ionia County layer facilities, and the latest poultry outbreak updates from USDA APHIS reflect a third outbreak in Ionia County, at a farm that has 2.4 million birds. APHIS also reported a second outbreak at a hatchery in New Mexico's Roosevelt County and infections at a live-bird sales operation in Florida's Miami-Dade County.