Wednesday, April 3, 2013

Synthetic Vaccine For Foot-&-Mouth Disease Under Development; Method Could Be Used Against Polio

Medical Updates

Synthetic vaccine: The newly proposed vaccine is composed of synthetically produced empty shells of the foot-and-mouth disease virus, seen here in a computer model. It contains no genetic material. The method could be extended to produce human vaccines, such as those to eradicate polio.
Image Credit: Pirbright Institute, UK
Source: Nature

An article, by Zoe Cormier, in Nature News says that a new synthetic vaccine, free of genetic material, could be available in six to eight years to combat foot-and-mouth disease, a common disease that is costly both to animals and to the economy they support.

Cormier writes:
Virologists have devised a way to create an entirely synthetic vaccine for foot-and-mouth disease. The vaccine could prevent future outbreaks of the disease, and potentially lead to new treatments for polio and other human diseases. Bryan Charleston, head of the Livestock Viral Diseases Programme at the Pirbright Institute in Woking, UK, and his colleagues used computer simulations to create a model of the protein shell of the virus that causes the disease, then reconstructed it from synthetic protein components. The synthetic shell contains no genetic material, and so it cannot infect the animals. But it will spur the immune system to produce antibodies that would protect them from the real virus. 
In 2001, an outbreak of foot-and-mouth disease in the United Kingdom led to the destruction of nearly 10 million animals. It cost the economy an estimated £8.5 billion (US$12.9 billion) in agricultural and tourism costs, and spurred a decision to protect against future outbreaks with vaccination rather than mass slaughter. In 2007, however a vaccine made from inactivated virus caused another UK outbreak. The authors say that there is absolutely no chance that their new vaccine could revert into an infectious virus because it contains no viral genes. Also, being entirely synthetic, it cannot be contaminated with live virus during manufacturing.

It will be 6–8 years before the vaccine is available to farmers, they estimate. But if the method used to create the vaccine proves successful when scaled to commercial production, it could also be used to create vaccines for human diseases that are caused by viruses of the same family, such as hand, foot and mouth disease, which is ubiquitous in Southeast Asia, and polio, which still blights the lives of millions of people in the developing world.
That the method of producing synthetic vaccines could also be used to prevent polio is also good news. Polio is endemic in only three countries—Afghanistan, Nigeria and Pakistan, and it has also appeared in a few other nations in sporadic outbreaks. Over-all the news is good that humanity can eradicate polio from a list of diseases that harm us. There is no cure for polio; thus the need for vaccines to prevent its debilitating effects.

The World Health Organization says: “Polio cases have decreased by over 99% since 1988, from an estimated 350 000 cases in more than 125 endemic countries then, to 650 reported cases in 2011. In 2012, only parts of three countries in the world remain endemic for the disease–the smallest geographic area in history–and case numbers of wild poliovirus type 3 are down to lowest-ever levels.”

And as the Nature article says: “Viruses are all very different from each other, and each will come with its own set of problems to solve,” says co-author David Stuart, a structural biologist at the University of Oxford, UK, who is working with the World Health Organization and the Gates Foundation to apply the techniques to the eradication of polio. ”But if we could use this to move away from inactivated polio viruses in the vaccines, it would have very powerful impacts because we are so close to ending this disease.”

You can read the rest of the article at [NatureNews]

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