SYDNEY • Government and academic experts in the United States have developed a vaccine against African swine fever that has proven 100 per cent effective, the American Society for Microbiology said last week.

Both high and low doses of the vaccine, developed from a genetically modified prior strain of the virus, were effective in pigs when they were challenged 28 days after inoculation, a report said.

"This new experimental... vaccine shows promise, and offers complete protection against the current strain currently producing outbreaks throughout Eastern Europe and Asia," said Dr Douglas Gladue, principal investigator at the US Department of Agriculture, which developed the vaccine.

The virus has been most devastating for China - the world's biggest producer of pork - which first reported a case about 1½ years ago. Since then, hog herds have been decimated, with the impact ricocheting across global agricultural markets.

Scientists from China to the US have been racing to develop a vaccine for the virus, which is deadly to pigs but is not known to harm humans.

There is no commercially available vaccine against the disease, which was first discovered more than 100 years ago in Africa.

In its most virulent form, the virus can be 100 per cent lethal. It infects pigs and wild boars, and outbreaks have been found in Eastern Europe, Russia and across Asia, including Vietnam and South Korea.

Despite 50 years of research, scientists have not managed to develop a vaccine that is safe and effective against African swine fever. In China, reports of unauthorised and experimental vaccines surfaced last year.

Research into the vaccine started after a 2007 outbreak of the virus in the Republic of Georgia, Dr Gladue said. More work needs to be done to meet regulatory requirements ahead of commercialisation, he added.

BLOOMBERG