Foot-mouth vaccine emerging from research

Press, 25 November 1981, Page 15

Foot-mouth vaccine emerging from research

NZPA London A genetically engineered foot-and-mouth disease vaccine is the front runner emerging from novel medical and veterinary compounds being investigated in the United States. “The Times” has reported. The newspaper's science editor, Pearce Wright, says three of the. world's leading research teams in animal virus diseases have followed slightly different routes to make experimental quantities of a vaccine extract. Each of the groups is collaborating with one of the science-based firms specialising in biotechnology, he says. Control of the disease on the European mainland and other parts of the world is by vaccination using a preparation made by inactivating an infectious virus.

There is strong evidence that the source of the epidemic earlier this year, which spread from Brittany to Normandy and then to Jersey and the Isle of Wight, was either through a vaccine in which the virus had not been inactivated, or from a culture that got through the legally required containment barrriers. Analysis of the genetic part of the virus particle shows a long chain molecule of 8000 building blocks (nucleotides). Using the recent methods devised for genetic manipulation, scientists found that only one fragment about a g tenth of the length of the molecule is the part crucial for vaccine production. That is referred to as virus protein one, VPI. Wright says VPI stimulates the defence system of

an infected animal to produce antibodies that try to neutralise the virus. Dr Frederick Brown, the deputy director of the Animal Virus Research Institute. describes this process as a straightforward application of biochemical and genetic manipulation methods.

But samples of VPI being obtained from bacterial cultures have a very low activity, and this is attributed to the shape of the . molecule. Yet the shape is vitally important in the production of vaccine. Defensive antibodies produced by the body, whether an animal or a human, are molecules that reecognise and have an affinity for the shape of the molecules which they are designed to neutralise. Wright says.