U.S. scientists have spent several years developing a vaccine for foot-and-mouth disease (FMD), one of the world’s most contagious animal viruses that could cost the U.S. economy more than $50 billion, experts estimate.

The vaccine is expected to be licensed within the next several months.

“This is probably one of the most important innovations in the last 60 years in foot-and-mouth disease,” says Luis Rodriguez, research leader of the foreign animal disease research unit at the Plum Island (NY) Animal Disease Center, where the vaccine has been developed under top security.

FMD vaccines already exist – the problem is they are of limited use because veterinarians cannot distinguish vaccinated animals from infected animals – both test positive for the disease.

In contrast, the new vaccine will feature an antibody test that will enable veterinarians to tell the difference between field infection and vaccination, researchers explain.

And the vaccine will be safe to manufacture in the United States because it does not use the whole live virus and cannot replicate, says Larry Barrett, director of Plum Island.

“In the United States, you can only work on FMD in an island environment, which is why we came here 60 years ago,” he says. “They wouldn’t allow us on the mainland.”

The vaccine works by triggering an immune response. A part of the foot-and-mouth disease virus is placed in a harmless vector – a defective human virus.

Then the vaccine is injected into the animal, providing immunity to fight FMD.

“The animal actually makes the vaccine inside its body by producing the FMD protein necessary to create an immune response,” Rodriguez explains.

“It’s a very good innovation – the most effective way to date and very promising technology. I think it’s going to revolutionize the way we look at FMD vaccines around the world today,” he says.

Research is also underway to develop new vaccines at the Institute for Animal Health in the United Kingdom (UK).

New FMD vaccines in the UK are using only the proteins, not the live genome part of the virus, which is why they are safe to produce, scientists say.

In developing their vaccine, the British team is producing the protective virus in insect cells instead of a defective virus. As with the vaccine developed at Plum Island, it is extremely stable and can be deployed rapidly to stem an outbreak, Rodriguez says.

The hope is that the new FMD vaccine will offer extended duration of immunity that will make its use suitable for countries where the disease is endemic.

“In some cases, current vaccines are only effective for three to four months, which means livestock need to be vaccinated three or four times a year. The cost of gathering the animals alone is significant – it’s just not practical,” he says.

This report was extracted from the BBC.