ASF vaccine on track for unveiling

March 10, 2021 | 15:42
(0) user say
The government is placing its faith in a commercial vaccine to African swine fever being available perhaps as soon as the end of the second quarter this year, but issues of cost and safety will linger for some time yet.
1534 p15 asf vaccine on track for unveiling
ASF vaccine on track for unveiling, source:

According to Deputy Minister of Agriculture and Rural Development Phung Duc Tien, it is expected that at the end of the second quarter or the beginning of the third quarter, there will be a commercial African swine fever (ASF) vaccine to serve the development of domestic livestock.

The comments were made at a February 23 meeting to discuss implementation of the livestock strategy for the 2020-2030 period and report on the disease situation and progress of ASF vaccine production.

According to a report from Navetco National Veterinary JSC, under the Ministry of Agriculture and Rural Development (MARD), the vaccine is capable of protecting 100 per cent of vaccinated pigs. In production conditions, the vaccine has protected around 80 per cent of pigs, which are continuing to be monitored for three and a half months after vaccination.

“Up to now, there have been five successful trials of the vaccine, with an immune response of 94.7 per cent,” said Tien.

The MARD is coordinating with relevant units to complete the production process of freeze-dried vaccines and five batches have been produced with more than 100,000 doses.

At the end of last December, at a meeting with leaders of the MARD, a representative of Navetco announced successful testing of a vaccine for the ASF.

After the news was shared, shares of Navetco (VET on the Unlisted Public Company Market) have since soared. From a price at around $2-2.50 apiece in early December, VET reached $4.50 at the end of January, and it remained around $3.65 a fortnight ago.

Capitalisation of Navetco has soared significantly in that time. From almost $40 million in early December, the figure hit more than $72 million at the end of January and sat at $58.5 million towards the end of February.

Tien said that the MARD is currently evaluating potential cost factors for the vaccines. Because Navetco is a state-owned enterprise, social benefits must be of top concern, he said, while accounting for business to contribute to efficiency must also be taken into account.

“We are determined that the cost of one dose of the ASF vaccine is not too high compared to the cost structure of domestic pork production and meeting the benefit factor of society,” Tien said.

Tran Xuan Hanh, deputy director general of Navetco, told the MARD’s leaders last December that the vaccine was being developed based on US genes. The United States has studied the virus for 10 years and, in February last year, Vietnam requested the US to transfer genetically-altered samples of the virus it has developed to facilitate vaccine production.

The Plum Island Animal Disease Center (PIADC), a federal research facility located in New York, has paved the way for a prototype through years of work. In December 2019, the US Department of Agriculture announced a vaccine that could create sterile immunity against the ASF virus.

On the progress in Vietnam, Dr. Douglas Gladue at the PIADC said in January, “This builds upon our initial study at the PIADC and has been repeated with the same results by Navetco.”

However, Gladue admitted there will still be a lot of work to carry out. “Questions remain on whether or not the vaccine is easy to make, whether or not it will keep its original qualities when produced at a mass scale, whether there will not be genetic changes in the original vaccine strain, and if any further side-effects will be noted,” he said. “Vaccine efficacy testing has to happen at a very biosafe locations.”

Indeed, safety is still of utmost concern as nations scramble to create successful vaccines. Even though a double gene-deleted vaccine currently being used in China could reduce mortality, for instance, it can still contribute to increased spread of the virus.

Dr. Paul Sundberg, executive director of the Swine Health Information Center in Iowa, said health officials in North America are monitoring the use and risk of such unapproved ASF vaccines in China.

“There are a variety of different vaccines that are being tried out to manage the ASF outbreak that are manufactured in a variety of different ways and have all kinds of different effects,” Sundberg explained.

Double gene-deleted vaccines even have the potential to make ASF detection more difficult. “It is not a safe and effective vaccine. It still gives pathology, it still causes infection, it still causes the virus to circulate, and some of the pigs don’t survive,” he added.

On a national level, the ASF outbreak may affect Vietnam’s hog industry for at least five years, but if the industry adopts scientific biosafety measures, hog populations could return to previous levels within two or three years. However Sundberg believed the light at the end of the tunnel is still out of reach.

“Vaccines may be available commercially as early as this fall, but in my opinion that’s probably optimistic – if you want to under-promise and over-deliver we’re still years away from a safe and effective ASF vaccine,” he warned.

First diagnosed in Kenya in 1910 and now prevalent in many countries, African swine fever is a highly contagious viral disease that infects only pigs. It is currently present in around a dozen countries across Asia, notably in China, where an outbreak in 2018 is believed to have caused losses of up to 50 per cent among the country’s 400 million pigs. The epidemic has been widespread in Vietnam since that time, and killed almost 10 million pigs in the country.

As of the end of last year, the population was 27.3 million, equivalent to 88.7 per cent on-year. In January, the number of hogs in the country recovered, increasing by 16.2 per cent, according to the General Statistics Office. In the first two months of this year, the ASF epidemic affected a smaller area and the number of culled pigs thus far in the time period sat at around 2,000.

By Hara Nguyen

What the stars mean:

★ Poor ★ ★ Promising ★★★ Good ★★★★ Very good ★★★★★ Exceptional