A Professor with the Western College of Veterinary Medicine says, if they can be shown to be effective, subunit vaccines offer the potential to provide a cheap and efficient means of protecting pigs from Brachyspira associated swine dysentery. Researchers with the Western College of Veterinary Medicine are exploring the value of subunit vaccines to prevent Brachyspira associated diarrhea and have identified a couple of proteins that could potentially be used to help stimulate an immune response.
Dr. John Harding, a professor with the Western College of Veterinary Medicine, says with the correct antigen and the correct adjuvant, the hope is to find a combination that will provide a very good immune response that will neutralize the bacteria that propagates in the hind colin.
Clip-Dr. John Harding-Western College of Veterinary Medicine:
That is easy to do with a subunit protein because, once you determine which proteins are really important and there could be many proteins and the nice thing about this is you could continue to add those subunit proteins into the vaccine and they all may have an additive effect. They're generally easy to produce in a manufacturing facility or, in our case, in a laboratory.
There are many different what we call expression systems so we can cut out the sequence for that protein, we can put it into an E. coli or a yeast cell and then, in our case, E. coli will propagate and produce that protein. It can be purified and throw it into a bottle and mixed with an adjuvant.
That's the advantage of subunit vaccines. Once you identify the right protein, they're relatively easy to grow and produce, unlike growing Brachyspira which is very expensive and it grows very very slowly and it's finicky when it grows. So, subunits are going to be far more cheap, efficient and effective if we can get this system to work.
Source : Farmscape