SCIENTISTS at The Pirbright Institute have destroyed the final archive stocks of rinderpest virus held in the World Reference Laboratory for the disease.

This was a major milestone in the World Organisation for Animal Health (OIE) and Food and Agriculture Organization of the United Nations (FAO) programme to ensure the world remains free from the eradicated disease. Pirbright's scientists have been leading the ‘Sequence and Destroy’ project to eliminate virus samples held in the Institute, which will reduce the risk of rinderpest re-emerging through accidental or deliberate release.

Rinderpest virus caused the most lethal cattle disease ever known, but after a huge global campaign it officially became the second disease to be eradicated from the world, after smallpox, in 2011. However, at that time, more than 40 laboratories across 36 countries still held samples of rinderpest, leaving the world vulnerable to a re-occurrence of the disease.

To reel in these viral samples, FAO and OIE designated some high containment laboratories as 'Rinderpest Holding Facilities', including Pirbright, and encouraged other laboratories to send their rinderpest samples to these designated holding facilities.

A 'Sequence and Destroy' project then targeted the destruction of virus stocks – apart from a minimal number of reference samples – after their genetic information was recorded through full-genome sequencing. In this way, the biological data is retained, whilst removing the risk posed by holding the live virus. As an OIE Reference Laboratory and a FAO World Reference Laboratory for rinderpest, Pirbright has led on the implementation of that project.

“The biggest risk of rinderpest re-appearing comes from an accidental escape from a laboratory, something that might be possible in the future if stocks are kept, even though no one is working on the virus," said Dr Michael Baron, Honorary Fellow at Pirbright and rinderpest expert for the OIE. "But at the same time we do not want to destroy what might be important biological information. By capturing that information and then destroying the oldest and largest archive of the actual virus, we hope to set an example to other laboratories and encourage them to get rid of their remaining lab samples.”

Pirbright scientists have so far destroyed over 2500 samples under the 'Sequence and Destroy' project, and the destruction of the last archived virus stocks held there was described as a 'highly significant step' in securing global freedom from rinderpest – which is a good thing, considering the FAO's estimate that its eradication has avoided losses of $920 million every year in Africa alone.

“This is a culmination of years of work by Pirbright scientists and our international collaborators; virus samples from as far back as the 1950’s have been destroyed. I feel privileged to have had a part to play in securing our future from rinderpest," remarked Dr Carrie Batten, chair for the Rinderpest Holding Facility Network and leader of the Non-Vesicular Disease Reference Laboratory at Pirbright.

“The samples were destroyed in The BBSRC National Virology Centre: The Plowright Building, the UK’s flagship high containment facility for livestock diseases that houses the latest genetic sequencing capability. The building is named after Walter Plowright, who developed the rinderpest vaccine that was used to eradicate the disease. It is very appropriate this is where the stocks of rinderpest virus are destroyed," added Dr Bryan Charleston, director of The Pirbright Institute.