Foot-and-mouth disease is one of the world’s most contagious animal viruses. Although it does not infect humans, an outbreak in the US could cost the economy more than $50bn (£31bn), experts estimate.
To avert such a calamity, scientists working for the US government have spent several years developing a foot-and-mouth vaccine. It is expected to be licensed for use in the next few months.
"This is probably one of the most important innovations in the last 60 years in foot-and-mouth disease," says Dr Luis Rodriguez, research leader of the foreign animal disease research unit at the Plum Island Animal Disease Center, where the vaccine has been developed under top security.
Vaccines already exist but are of limited use because veterinarians cannot distinguish vaccinated animals from infected animals – both test positive for foot-and-mouth.
Plum Island Animal Disease Center
The new vaccine will come with an antibody test that will enable regulators to tell the difference, the researchers say.
And it will also be safe to manufacture in the US because it does not use the whole live virus and cannot replicate, says Dr Larry Barrett, director of Plum Island, a US Department of Homeland Security installation.
"In the US, 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 virus is placed in a harmless vector – in this case a defective human virus.
The vaccine is then injected into the animal, providing it with the relevant genetic information its immune system needs to fight the foot-and-mouth virus.
"The animal actually makes the vaccine inside its body by producing the FMD protein necessary to create an immune response," says Dr Rodriguez.
"It’s a very good innovation – the most effective way to date and very promising technology. I think it’s going to revolutionise the way we look at FMD vaccines around the world today."
British effort
Research into new vaccines is also underway at the Institute for Animal Health (IAH) in the UK.
The foot-and-mouth virus is a genome surrounded by a coat of proteins. The new vaccines use only the proteins – not the live genome part of the virus – which is why they are safe to produce, the scientists say.
The British team is developing a vaccine that is produced in insect cells instead of a defective virus. Like the vaccine developed at Plum Island, it is extremely stable and can be deployed rapidly to stem an outbreak, he says.
He hopes the vaccine will offer a longer lasting immunity to foot-and-mouth that will make it suitable for use in 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.
Only one major animal disease has been successfully eradicated so far – rinderpest – but scientists hope their work will one lead to the elimination of foot-and-mouth disease.
Source: BBC