Picornaviruses, (RNA viruses) are responsible for a
range of human and animal diseases such as polio, certain forms of the common
cold and foot-and-mouth disease (FMD). The severity of these diseases varies, with respect to both health and
economic costs. Outbreaks of FMD in the UK in 2001 resulted in the slaughter of about 6
million animals and costs over of £8 billion.
Effective and safe picornavirus vaccines could be made from
recombinant virus-like particles, they would be void of a viral genome and thus
lack the ability to propagate. However, synthesising stable forms of such
particles at scale has so far been difficult.
Currently vaccine
production utilises inactivated virus produced in large bioreactors in high
containment facilities, additionally distribution often requires a cold- chain* to maintain stability of the
viral capsids. This is often less than satisfactory for several reasons: set-up and
running costs are high, restricting global production capacity and storage and
supply are constrained by the poor vaccine stability at ambient temperatures.
Recent work by Claudine
Porta et al (2013) on the Foot-and-mouth disease virus (FMDV) has addressed
these drawbacks. The work was carried out at Diamond - the UK's national synchrotron,
where researchers developed methods to efficiently express recombinant empty
capsids in quantities potentially
attractive to industry.
Furthermore, researchers incorporated a rationally designed
mutation that enhances capsids stability. X-ray crystallography revealed that
stabilised and wild-type empty capsids have essentially the same structure as
intact virus. This method of vaccine antigen production has numerous potential benefits
in comparison to current technologies by dropping production costs, eliminating
the risk of infectivity and enhancing the temperature stability of the product.
Additionally the complete lack of FMDV non-structural proteins resulting from
the vaccine production will eventually lead to the development of tests to
diagnose infected from vaccinated.
The strategies and methods employed to formulate the improved FMDV
vaccines can be directly applied to viruses pathogenic for humans.
This is not a marine study, however it’s an important
break through. In the future one might consider similar techniques for the control
and prevention of viral infections within the globally growing industry of
aquaculture.
* A cold
chain is a temperature-controlled supply chain, common in the food and pharmaceutical industries to
prolong shelf life.
Porta C, Kotecha A, Burman A, Jackson T, Ren J, et al. (2013) Rational Engineering of Recombinant Picornavirus Capsids to Produce Safe, Protective Vaccine Antigen. PLoS Pathog 9(3): e1003255. doi:10.1371/journal.ppat.1003255
Hi Sean,
ReplyDeleteI was just wondering if this means that humans and animals do produce antibodies to the virus then? And it is the same for both humans and animals?
Robyn
Hi Sean,
ReplyDeleteIs the foot & mouth virus still a threat? I thought it was wiped out!
And in your conclusion you've stated that this method can be used in aquaculture, so in addition to Robyn's question, does this mean fish produce antibodies as well?
Thanks, Harri
Hello Robin,
ReplyDeleteThanks for the interest!
Yes they tested the vaccine (containing the 'empty' capsids) on cattle, and found immunisation after 3 weeks, additionally they found neutralising antibodies after primary immunisation. However as far as I'm aware this type of vaccine has not been tested on people but the belief is that this type of vaccine production could be applied in viruses that pose a threat to humans.
I hope that answered your question.
Hi Harry,
ReplyDeleteThanks for the question.
Whether the Foot and Mouth virus still poses a threat to the agricultural industry is most likely, the subject of another paper. However a place to look may be DEFRA. I’ve just had a look and the disease is still notifiable. So my best guess is that Foot & Mouth is under control but its still possible for outbreaks to occur.
Based on the research I believe this method could prove useful if applied to aquaculture in the future. However as of yet I am unaware of any studies testing this method on fish.
Hope that helps,
Yes that did, thank you.
ReplyDeleteIt would be really interesting for them to test it on people too, given that the assumption is that most viruses are quite species-specific...
Your welcome,
ReplyDeleteYes, I agree it would be interesting to find out if this method is applicable to human viral diseases but I guess we'll have to wait and see ...