Scientists at the Plum Island Animal Disease Center (PIADC) have developed a molecular vaccine against foot and mouth disease virus (FMD). The new vaccine does not use live FMD virus for vaccine manufacture, allowing for differentiation between an infected animal from an inoculated animal using common diagnostic tests.
Traditional vaccines containing live virus have made it difficult to determine whether an animal is actually infected, or has simply been exposed to the vaccine. Without this clear differentiation, such animals would be prohibited from entering any country that is designated FMD free.
The FMD viral structure includes genetic material surrounded by a coat of proteins called a capsid. The new vaccine produces only the virus coat particles, which form empty viral capsids, and not the entire genome of the virus; thus it lacks the infectious viral nucleic acids. When the vaccine is injected into the animal the resulting empty viral capsids trigger a protective immune response. (Source: DHS)
While noting that this virus only protects against one strain of FMD, the researchers are confident this breakthrough will pave the way for developing better countermeasures against all strains of the highly contagious disease. “This is the biggest news in FMD research in the last 50 years,” says PIADC Director Dr. Larry Barrett. “It’s the first licensed FMD vaccine that can be manufactured on the U.S. mainland, and it supports a vaccinate-to-live strategy in FMD outbreak response.”
The new vaccine, originally discovered by Dr. Marvin Grubman in the USDA Agricultural Research Service at PIADC, took seven years to develop and license. Dr. Bruce Harper, Director of Science at PIADC and the manager over PIADC’s Targeted Advanced Development Branch, led the development team, who worked with industry partners GenVec Inc., a biopharmaceutical company in Gaithersburg, Maryland, and Antelope Valley Biologics, a Benchmark Biolabs affiliate in Lincoln, Nebraska.
“The absence of the nucleic acids of the real virus allows us to differentiate between vaccinated and infected animals,” said Grubman. “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.”
The vaccine was last month granted conditional license for use in cattle by the USDA Animal and Plant Health Inspection Service (APHIS) Center for Veterinary Biologics. Under the conditional license, the product may be distributed should the need for it arise, as authorized by federal emergency management officials within USDA. APHIS issued the conditional license to Antelope Valley Bios, Inc., who manufactured the vaccine under a contract from GenVec.
PIADC has entered into a cooperative research and development agreement with Merial, the animal health division of Sanofi, to evaluate the FMD vaccine production process. GenVec has licensed to Merial the rights to develop and commercialize their proprietary vaccine technology for use against FMD.
