by Leah Douglas

LONDON: Agriculture Secretary Tom Vilsack told Reuters on Wednesday that 24 companies are working on developing an avian flu vaccine for cattle, as the virus spreads among US dairy cattle.

According to the US Department of Agriculture (USDA), 90 dairy herds in 12 states have been infected with bird flu since the end of March. Three dairy farm workers have also been infected with the virus, two in Michigan and one in Texas.

A vaccine could reduce the risk of bird flu spreading to new species and reduce potential economic losses for dairy farmers, but it could take years to develop.

Zoetis, an animal healthcare company said it began development of a vaccine for dairy cattle this spring. Merck Animal Health said it is evaluating technologies and strategies that would allow a timely response to emerging diseases in cattle, including bird flu.

In addition to the two dozen companies working at various stages of vaccine development, the USDA is conducting its own initial research on a vaccine at its lab in Ames, Iowa, Vilsack said in an interview.

He said the agency is looking for a vaccine candidate to test for efficacy.

“It could happen tomorrow, or it could take six months or a year,” Vilsack said.

The agency’s other efforts on bird flu include research on possible respiratory spread of the virus among cows and providing assistance to farmers in the fight against bird flu. Biosecurity on farms,

Although wild birds are the main vectors for bringing bird flu to poultry farms, the main threat of spread to dairy farms appears to be from the movement of people and equipment, he said.

“For dairy cows, it’s not just about migratory birds, it’s about the movement of cows, it’s about people, vehicles and equipment that may be carrying the virus, that they don’t even realize they’re carrying,” he said. “So biosecurity becomes incredibly, incredibly important.”

Vilsack said a pilot program for bulk milk testing will be launched “in the very near future.” The program aims to expand testing for the virus, while also enabling healthy herds to move across state borders without requiring negative tests from every cow.

Vilsack said Michigan and Idaho are among the states that have shown interest in the program. (Reporting by Leah Douglas. Additional reporting by Tom Polansek in Chicago. Editing by Bill Berkrot)