February 26, 2020
US scientists say commercial ASF vaccine to be released in two to five years
US government scientists said they have developed three vaccine candidates to prevent African swine fever (ASF) in swine, but it will take years before any of them will be available for commercial use, reported United International Press.
Douglas Gladue, US Department of Agriculture (USDA) research microbiologist said the vaccine is 100% effective when used at a very low dose, with no sign of the disease of fever in swine. Gladue worked with Manuel Borca to develop the ASF vaccine candidate, with test results published in January 2020.
Gladue said this is only the first step in the vaccine's path to mass production and distribution to producers in the United States and around the world.
The vaccine must first be manufactured by a private company, of which the USDA will negotiate a licensing agreement with. Then, the vaccine will undergo more tests before it will be produced in larger quantities, said Liz Wagstorm, National Pork Producers Council chief veterinarian.
Freshly harvested cells from living swine were used to develop the USDA vaccines, but it must be grown in a different kind of cell for the vaccine to be mass produced as consistently collecting samples from live swine is not sustainable for mass production.
Wagstorm said companies that develop vaccines have "immortal cells" stored in "banks" which is used to grow expands. The cells grow in cultures and do not die. They differ from live cells grown from extracting livestock samples, so they may not survive the transfer to "immortal" cell lines. Once transferred, they need to be tested once more as to not harm the swine.
Once the expanded tests return positive, it will take months or years to grow enough vaccine for the 75 million strong swine herd in the United States alone.
Tanya Brown, a USDA spokeswoman said it will take between two to five years before an ASF vaccine can distributed commercially.
Gladue said US government scientists are continuing to develop new vaccine candidates, noting that private companies and universities are conducting their own research on the subject.
An oral ASF vaccine has successfully immunised wild boar in Spain in early tests, and the Harbin Veterinary Research Institute in China is currently testing two vaccine candidates. There are also unauthorised vaccines distributed among swine farmers in China.
As viable ASF vaccine won't arrive anytime soon, the swine industry in the United States will continue to beef up border protection measures and increase biosecurity efforts on farms.
- United International Press