Foot-and-Mouth Disease Vaccines

By George Grow

This is the VOA Special English AGRICULTURE REPORT.

American scientists are developing new vaccine medicines against Foot-and-Mouth Disease. They hope to stop serious infections like the one now in Europe. Currently, foot-and-mouth disease vaccines are made from a virus that causes the disease.

Such vaccines use a killed or weakened virus. However, experts say the current vaccines are difficult to use. They say such vaccines offer only short-term protection against foot-and-mouth disease.

The United States Department of Agriculture is working to develop more powerful and longer-lasting vaccines. The Department operates the Plum Island Animal Disease Center. It is near the coast of Long Island, New York. The center is the only American laboratory with enough security to safely study the virus.

Peter Mason directs the foot-and-mouth disease research team at Plum Island. He says the team is using genetic engineering to develop several new kinds of vaccines. One new kind of vaccine uses genetic material from the virus. It is injected into the animal. The D-N-A molecules cause the animal to make proteins similar to those produced by the virus. This helps the animal to develop resistance to the disease.

Another method involves pieces of genetic material from the
foot-and-mouth disease virus. Scientists put this D-N-A material into other harmless viruses. When injected into a healthy animal, the changed viruses can cause resistance to fight foot-and-mouth and other diseases.

Mr. Mason says both experimental vaccines would be effective for controlling infections among large numbers of animals. He says the vaccines help build up natural resistance quickly and safely among animals near infected areas.

The American scientist says tests with the new vaccines are hopeful. However, they probably will not be ready to be used for several years. He adds that it is not likely that foot-and-mouth disease will ever be stopped completely. That is because the virus changes easily and is too widespread.

Mr. Mason says the successful prevention of the disease will depend on more than vaccines. He says there must be effective national agricultural systems to identify disease and enforce vaccination campaigns.

This VOA Special English AGRICULTURE REPORT was written by George Grow.