HANOI: At least 100 pigs have died in Vietnam within two weeks of being vaccinated with a new locally made African swine fever vaccine, prompting authorities to stop the inoculation.
Pig farmers in the central Phu Yen province have reported that dozens of their animals died after being sick since being vaccinated.
According to a report in the Vn Express, 57-year-old farmer Le Hung Vuong from the Phu Hoa district said his family had been raising 34 pigs, including seven pregnant sows, and all were vaccinated two weeks ago.
He said all the animals lost their appetite and developed fever, suffered skin haemorrhages and there was blood in their urine within a few days and many of them later died.
"Before getting the vaccine shots, all of them were in normal condition," said another farmer from the same district.
Tran Dinh Thuan, 48, said 28 of her pigs were vaccinated the same day as Vuong and within days, 17 of them died while the remaining 11 fell seriously ill.
According to veterinary official Duong Ba Truc, more than 150 pigs were vaccinated on Aug 13 and 14.
He said farmers bought the vaccines from the livestock and veterinary agency of Phu Hoa district and either inoculated their pigs themselves or sought help from veterinary officials.
Agency chief Nguyen Ngoc Duc said a preliminary assessment showed that the pigs died due to a "reaction" from the vaccine.
The Vn Express reports him saying that the vaccine used was the NAVET-ASFVA that was produced by Ho Chi Minh City-based company Navetco National Veterinary JSC. The company was licensed by the Ministry of Agriculture and Rural Development in May.
About 600 pigs in the province have so far been inoculated with the vaccine. Of them, more than 100 had died at 24 farms across the province while more than 400 others experienced adverse reactions.
The province has stopped the vaccination until further notice and Navetco has sent its experts to Phu Yen to investigate the deaths. Samples taken from sick pigs will also be sent to the Department of Animal Health's laboratories for testing.
In 2020, Vietnam started work on producing a vaccine for the African swine fever with the help of American experts.
They then developed the NAVET-ASFVA, the first vaccine against the disease since it was detected in Africa in 1921.
Vietnam suffered an African swine fever outbreak three years ago that spread to all 63 provinces and cities within a span of seven months.
In 2021, the disease was found in 60 localities, causing 288,660 pigs to be culled.
African swine fever is harmless to humans but is fatal to pigs. Authorities estimated that the outbreaks cost Vietnam over VND30 trillion (US$1.29 billion) in losses, and affected 3.5 million farmers and hundreds of businesses.
The Vn Express had also reported that there were over 4,000 research projects related to the disease and vaccine development but no commercial vaccine was available.
This prompted authorities to push for the development of the vaccine and five lab trials were conducted before approval was granted.
The vaccine is said to be able to protect at least 80 per cent of vaccinated pigs and they can retain immunity for six months.
The Agriculture Ministry had said that it enlisted several scientific councils and scientists to evaluate its effectiveness before approval was granted.
The United States Agriculture Research Service had also reportedly said the vaccine was safe and effective, according to the report.
Since it is a new vaccine, authorities had said it will first be sold on a small scale and given to around 600,000 pigs aged between eight and 10 weeks.
They will then evaluate the results before considering nationwide distribution. However, the deaths of the pigs are expected to delay the plans, pending a review.