US develops new FMD virus-free vaccines
The vaccine has been created at the Department of Homeland Security Science and Technology Directorate’s (S&T) high-containment Plum Island Animal Disease Center (PIADC) and can be used to differentiate infected and inoculated animals by using common diagnostic tests.
PIADC sirector Dr Larry Barrett explained that the news is the biggest in FMD research in the last 50 years. He said: “It’s the first licensed FMD vaccine that can be manufactured on the US mainland and it supports the vaccinate-to-live strategy in FMD outbreak response.”
As the US is an FMD-free zone, and has been since 1929, no vaccines created by using the FMD virus can be administered or produced in the country, which also means that animals vaccinated outside the US with a traditional inoculation would also be prevented from entering the country.
Originally discovered by Dr Marvin Grubman from the US Department of Agriculture (USDA) Research Service at PIADC, the vaccine has been in development and licensing for seven years and is a defence against a possible outbreak of FMD in the US, which, if it happened, would cost an estimate of more than $5bn. The vaccine produces FMD virus coat particles (a shell) only, which forms a protein called a capsid. As it is only made up of a protein shell, the vaccine is missing part of the virus’ genome and so has no infectious viral nucleic acids, which means the virus is not present. The empty viral capsids, however, are enough to trigger a protective immune response when injected into the animal.
Grubman said: “This is critical when determining that an animal is free of infection after an FMD outbreak. Now it will no longer be necessary to destroy all the animals in a herd when just a few become infected.”
Branch chief at the PIADC Dr John Neilan developed a way to address the immune response to the vaccine, which made it possible to achieve the level of effectiveness required for a USDA license. The vaccine was recently given a conditional licence for use in cattle by the USDA Animal and Plant Health Inspection Service’s Centre for Veterinary Biologics and can also be distributed if an outbreak arises.
S&T’s Agricultural Defense Branch chief Michelle Colby said: “Our work isn’t over yet, This vaccine protects against just one strain of FMD, so this is just the tip of a growing iceberg.”
