HEAL ▶▶▶TH


Plant-based vaccine coming for CSF


The world’s first plant-based livestock vaccine (for Newcastle disease in poultry) was approved in 2006 in the USA. Now, there is one for Classical Swine Fever (CSF, also known as hog cholera) in pigs.


BY TREENA HEIN, CORRESPONDENT B A


ecause of the advantages that plant-based vaccines have in comparison to other types of vaccine, more of them for pigs and other livestock may be coming. The production of plant-based vaccines falls under


what is known as biopharming or plant molecular farming, where genetically modified plants are used to produce a wide range of pharmaceuticals and industrial products.


Efficient way to deliver vaccines “Early work on plant-based pharmaceuticals focused on


using food crops such as corn and rice to hopefully develop a cheap, efficient way to deliver vaccines,” explains Dr Donald Stewart, CEO of the Canadian plant-based biopharmaceu- tical company PlantForm Corporation. “However, progress in this area slowed around 2002 due to concerns about cross-contamination of other field crops.”


Non-food crops Non-food crops like tobacco then came into the spotlight. Tobacco is very suitable for biopharming, with fast growth and genetics that are well understood. Over many years, tobacco plants have been genetically engineered to produce therapeutic proteins, monoclonal antibodies and vaccines to treat cancer, inflammatory diseases and other conditions. Other plants used in biopharming include duckweed, moss and alfalfa. Compared to other culturing systems for biological drugs, plant-based systems are cheaper, faster and larger in capacity, with unlimited scale-up potential. They also offer lower risk


Figure 1 - The manufacturing platform of a plant-based vaccine. From seed to biopharmaceutical in six weeks.


1 Generate biomass Grow


Nicotania benthamiana from seed


4 weeks B Grow


Agrobacterium containing genetic sequence for target drug


3 days 7


Package product


1 day


Fill vials


1 day 6


5 Purify drug Using standard antibody process


4 days 4


Extract drug


1 day 2 Infiltrate


plants with Agrobacterium


1 day 3


Generate product Plants grow, producing drug in each cell


1 week


▶ PIG PROGRESS | Volume 38, No. 3, 2022


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