The Ministry of Agriculture and Rural Development is working with a visiting delegation from the U.S. Department of Agriculture on cooperation in developing a vaccine against the African swine flu, a deadly incurable disease that is believed not to afflict humans.

The Vietnamese side has asked for samples of the genetically modified African swine fever virus the U.S. has successfully developed to serve the work of making vaccines in Vietnam.

They have also suggested that Vietnamese technical staff are taken to the U.S. or experts from the U.S. visit Vietnam for a joint project on further studies of the disease and production of a vaccine.

Vietnam has also sent to the U.S. 20 separate samples of the African swine fever virus taken from 17 of its provinces so that the U.S. can continue working on the vaccine.

U.S. experts said last month they had developed a vaccine against African swine fever, which was confirmed by their experts at the Vietnam visit that ends Friday.

The vaccine was developed from a genetically modified prior strain of the virus by deleting a previously uncharacterized gene, I177L, to produce complete attenuation of the virus in swine, it was announced.

A report from the American Society for Microbiology said last month that both high and low doses of the vaccine were effective in pigs 28 days after inoculation.

The African swine fever was first detected in Vietnam in February 2019 before it spread to all 63 cities and provinces in the country seven months later, forcing the nation to kill around six million pigs, or 20 percent of the total hog herd.

The African swine fever virus is shed in blood, saliva, tears, nasal secretions, urine, feces, and secretions from the animal's genital tract. Pigs can thus get infected by mere contact with many different infected sources, mainly other infected pigs, pork and other pig-derived products, but also any other contaminated objects, according to the Food and Agriculture Organization.

Pork makes up three-quarters of total meat consumption in Vietnam, a country of 95 million people where most of the farm-raised pigs are consumed domestically.

The country's pork industry is valued at VND94 trillion ($4 billion), and accounts for nearly 10 percent of its agricultural sector.

With the domestic pork market hit hard by the viral disease, Vietnam's pork imports during the first 11 months of last year had more than doubled against the same period the previous year to 110,000 tons, according to the Ministry of Finance.

The Food and Agriculture Organization of the United Nations said that as of February 6, new or ongoing outbreaks have been detected in China, Cambodia, Indonesia, Laos, Mongolia, Myanmar, North Korea, the Philippines, South Korea, Timor-Leste and Vietnam.