Researchers at The Pirbright Institute have shown for the first time that vaccinating cattle at intervals with different types of foot-and-mouth disease virus (FMDV) can identify immune cells which recognise shared structures across FMDV types.
There are seven different types of foot-and-mouth disease virus (called serotypes), each of which require a different vaccine that should be administered every six months to ensure susceptible animals are protected. This proves costly for herd owners who may need to vaccinate against multiple serotypes circulating in their area. The demand for vaccines which protect against multiple serotypes is consequently very high.
Pirbright researchers have therefore focussed their efforts upon understanding which parts of the FMD virus are present across multiple serotypes that the cattle immune system will also respond to.
Immune cells, called B cells, are key for the effective clearance of an FMD infection, as they produce antibodies which neutralise the virus by binding to structures they recognise, called epitopes. By discovering B cells that are activated against multiple serotypes, Pirbright scientists hope to find shared epitopes, which could be used in future vaccines to prime the immune system against infection of multiple serotypes.
In their study, published in the Journal of Virology, researchers vaccinated cattle with four different inactivated FMDV serotypes at 21 day intervals. The cattle were tested for levels of antibodies and B cells which could be matched against the serotypes they had been vaccinated with in addition to those they had not been exposed to.
Researchers found that the four sequential vaccinations produced a B cell response against epitopes present on all four vaccinated serotypes as well as another serotype which the cattle had not been previously exposed to. This is the first study to show that this method of vaccination can reveal B cells that are triggered by epitopes shared across multiple FMDV serotypes.
Dr Bryan Charleston, Director of The Pirbright Institute, who led the research, said: “Our work provides evidence that different serotypes have common epitopes that can be targeted to induce an immune response against many serotypes simultaneously.
“These results clearly illustrate the potential for developing a vaccine regime that could improve the breadth of protection against FMD. The data generated from this study will enable us to further investigate ways of improving vaccination techniques”
This research was funded by the Welcome Trust Strategic Award (grant WT-101122Z13Z).
More information about FMDV and Pirbright’s research to prevent and control it, can be found on the Institute’s website.