In the world of livestock diseases, there are few foes more formidable than foot-and-mouth disease.

With seven main strains and 60 subtypes, a centuries-long track record of devastation, the ability to survive in soil for extended periods and be spread rapidly by infected animal breath, wind and other means, the virus has kept researchers like Marvin Grubman challenged for decades.

Grubman, of Southold, N.Y., is one of about 120 scientists who work at the Plum Island Animal Disease Center, a federal research lab in eastern Long Island Sound that is accessed from ferries in Old Saybrook and Orient Point, N.Y.

This summer, Grubman, lead scientist at the center, saw his more than three decades of work on the disease bear what are perhaps the most impressive results of his career. In June, a new foot-and-mouth vaccine he helped create was awarded a conditional license for use in cattle by the U.S. Department of Agriculture, shepherding in a new era in the ability of the United States to safeguard against the dreaded disease. He had received a patent on the vaccine in 2011.

"This vaccine is the biggest advance in vaccine technology for this virus in the last 50 years," Larry Barrett, director of the 58-year-old Plum Island center, said last week. "This is one of our biggest accomplishments."

The new vaccine, which protects cattle against one of the seven main strains - a type circulating in South America - is a significant breakthrough over existing vaccines on several fronts.

For starters, Grubman explained, it is the first foot-and-mouth vaccine to achieve its protective properties through the use of inactive virus. Current vaccines rely on live virus, making it impossible to determine through tests whether cattle have been vaccinated or are infected with the virus. Because of that, animals that receive the traditional vaccine are barred from entering countries that are free of foot-and-mouth disease, as has been the case in the United States since 1929.

But even though the virus has not erupted in this country, it continues to circulate in 100 countries around the world, and recent outbreaks have occurred in developed nations such as the United Kingdom and Japan, so there is no guarantee it won't return. That means the United States must remain prepared to do mass vaccinations if the need ever arises, Grubman said. But the United States, before the development of the new vaccine, was at the mercy of other nations for obtaining vaccine.

"The U.S. is dependent on foreign countries for our foot-and-mouth vaccine bank, and that's not an ideal situation, because foot and mouth spreads very quickly," Grubman said.

U.S. law now prohibits live foot-and-mouth virus anywhere on the mainland, a restriction designed to prevent accidental releases like the one that occurred at a lab in the United Kingdom in 2007, causing an outbreak to nearby livestock farms.

"That can happen, and has happened very recently," Grubman said.

The Plum Island center's offshore location allows research on the virus there, but no vaccine using live vaccine can be manufactured in this country. With the new vaccine using inactive virus, the there is now a domestic supply being developed.

"For the U.S., this is important," Grubman said, "because now we can produce it on the mainland, and we don't need an expensive containment facility."

Two private companies, GenVec Inc. in Maryland and Antelope Valley Biologics in Lincoln, Neb., are working with the Plum Island lab and the Department of Homeland Security to bring the vaccine into commercial production. As that happens, work continues on Plum Island to improve the new vaccine, Grubman said.

He and other researchers are working on making the vaccine work more rapidly. Now, a cow injected with the new vaccine develops protective antibodies within seven days, Grubman said. But even seven days can be too long when a foot-and-mouth outbreak is under way, because it spreads so rapidly. But, if the current research is successful, vaccine incorporated with interferon will given an animal protective properties in one to two days.

Grubman and his research team are also trying to develop vaccines using non-live virus for other strains of foot-and-mouth, and to reduce the cost of the vaccine.

"For animals, a vaccine has to be cheap," he said. "We're trying to reduce the cost by reducing the dose and enhancing the potency. We've already been able to reduce the dose quite a bit."

j.benson@theday.com