SwineHealth News for April 29, 2020

A novel approach to vaccine development offers the potential to create an effective vaccine for Step suis.
As part research being conducted on behalf of Swine Innovation Porc scientists are investigating a novel approach to creating a vaccine to prevent Streptococcus suis.
Dr. Marcelo Gottschalk, the Director of the International Reference Laboratory for Streptococcus suis at the University of Montreal, explains the challenge is the pathogen protects itself by encapsulating itself in a sugar-based envelope.

Clip-Dr. Marcelo Gottschalk-University of Montreal:
In the last year we have been working on a Strep suis protein candidate that may protect against all serotypes of Strep suis.
The problem is that results show that protection can be achieved with some of these candidates but the protection is not optimal.
Why?
Because we need the animals to produce antibodies against the capsule and this capsule shields the bacteria.
The problem is producing antibodies against the capsule, since they are sugar, is very difficult.
Animals do not produce high levels of antibodies against this sugar because the immune system cannot see the sugar.
You need these antibodies but the animals cannot produce them.
So, what can be done?
To increase the level of antibodies against that sugar, the capsule can be purified and then linked to a protein.
The mixture of the protein plus the sugar, the capsule, will generate antibodies against both.
The immune system will see the protein and then will see the capsule.
We have done this in the past and we have obtained very good protection.
We purify the capsule and mix the capsule with the protein and the results were very good.
One of the problems is the purification of the capsule is very expensive so the vaccine may be very good but cannot be used in swine production because it would be too expensive.

Dr. Gottschalk says, to reduce the costs, scientists are proposing to synthesize fragments of the sugar-based capsule and combine it with the protein to achieve a more cost-effective vaccine.
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Bruce Cochrane.

*SwineHealth News is produced in association with Farmscape.Ca and is a presentation of Wonderworks Canada Inc.