RESEARCHERS in the U.K. have developed a new methodology to produce a vaccine for foot and mouth disease virus (FMDv), according to an announcement from the U.K.'s Biotechnology & Biological Sciences Research Council (BBSRC).
Because the vaccine is all synthetic, made up of tiny protein shells designed to trigger optimum immune response, it doesn't rely on growing a live infectious virus and is, therefore, safer to produce, the announcement said.
Furthermore, these empty shells have been engineered to be more stable, making the vaccine much easier to store and reducing the need for a cold chain. BBSRC said this is important because it represents "a big step forward in the global campaign" to control FMDv in countries where the disease is endemic and could significantly reduce the threat to countries currently free of the disease.
This new approach to making and stabilizing the vaccine could also affect how viruses from the same family -- including polio -- are fought, BBSRC said.
This collaborative research was led by professor David Stuart at Diamond Light Source and the University of Oxford and Dr. Bryan Charleston at The Pirbright Institute.
Charleston, whose team at Pirbright has developed a detailed understanding of the immune response to FMDv in cattle and is leading the vaccination trials, said, "The FMDv epidemic in the U.K. in 2001 was disastrous and cost the economy billions of pounds in control measures and compensation. As a result of the outbreak, the Royal Society recommended that new approaches should be developed to control the virus should it happen again.
"Using our knowledge of the immune responses to FMDv in cattle, we were able to define the characteristics that needed to be incorporated into the new vaccine platform to induce protection," he added.
Stuart explained, "What we have achieved here is close to the holy grail of (FMDv) vaccines. Unlike the traditional vaccines, there is no chance that the empty shell vaccine could revert to an infectious form. This work will have a broad and enduring impact on vaccine development, and the technology should be transferable to other viruses from the same family, such as poliovirus and hand, foot and mouth disease, a human virus which is currently endemic in Southeast Asia."
Key results were published March 27 in the journal PLOS Pathogens. The work is principally funded by the U.K. Department for Environment, Food & Rural Affairs and the Wellcome Trust.
Clinical trials using the synthetic shell-based vaccine on cattle have shown that it is as effective as current vaccines, BBSRC said. While a commercial product is still several years away, the team hopes that the technology can be transferred as quickly as possible to make it available to a global market.
Stuart explained that the researchers "synthetically created empty protein shells to imitate the protein coat that forms the strong outer layer of the virus. By using Diamond's visualization capabilities and the expertise of Oxford University in structural analysis and computer simulation, we were able to visualize something 1 billion times smaller than a pinhead and further enhance the design, atom by atom, of the empty shells."
Pre-clinical trials have shown the new vaccine to be stable at temperatures of up to 56 degrees C for at least two hours.
FMD is endemic in central Africa and some parts of the Middle East and Asia (Map), so this is a major advantage over the traditional vaccine, which has to be produced and stored in a chilled and stable environment.
"The ability to produce a vaccine outside of high containment and that does not require a cold storage chain should greatly increase production capacity and reduce costs. Globally, there is an undersupply of the vaccine due to the high cost of production, and this new development could solve this problem and significantly control FMD worldwide," Charleston said.
"Furthermore, the complete absence of some viral proteins from this new vaccine will also allow companion diagnostic tests to be further refined to demonstrate the absence of infection in vaccinated animals with greater confidence," he added.