In Brief
Scientists at the John Innes Center have found a way to create a polio vaccine using a tobacco plant. The result was a "virus-like particle" that was similar enough to polio to prevent the disease, but unable to cause it.


Polio’s Last Days?

Polio cases have decreased by over 99% since 1988, but a recent breakthrough could lead to this disease’s elimination once and for all.

In an interesting way of using one virus to combat another, scientists at the John Innes Centre in Norfolk, England, “hijacked” a relative of the tobacco plant, and used its own metabolism to turn its leaves into the leafy equivalent of polio vaccine factories. The end result is a virus that looks and acts like the polio virus, but technically isn’t; it has everything needed to train the body’s immune system, but nothing that can pass on the polio virus — which can cause an infected person to eventually become paralyzed or suffer from meningitis.

Scientists began this process by taking the genetic code used to make the outer layer of the polio virus, and combining it with material from various other virus known to effectively infect plants. From there, the resulting combination was inserted into soil bacteria, which then went on to infect tobacco. After the infection took hold, the plants responded to the newly made genetic code and began making the virus-like particles that would later be extracted.

When used in preliminary animal tests, the particles completed prevented polio from occurring.

Speaking to BBC News, John Innes Professor George Lomonossoff called the particles “incredibly good mimics.”

A =  Virus-like particles (VLPs) in vitreous ice. B = Reconstruction of poliovirus. C = VLP showing empty internal surface. D and E = Resolutions of poliovirus. (Image Credit: John Innes Center)

A Replacement for the Polio Vaccine

The World Health Organization (WHO) has already provided funding towards this research, with the goal of using it to replace the polio vaccine still in use. Current polio vaccines utilize the actual polio virus, albeit a much subdued version; however, that poses a few risks, included its potential reintroduction into society.

The virus-like particles, and the process in which they were created, also aren’t exclusive to polio. There are plans to expand it to treat many other diseases, such as the flu, as well as outbreaks of new diseases. In theory, so long as the genetic code is available, as it was with polio, then a vaccine can be made.

“In an experiment with a Canadian company, they showed you could actually identify a new strain of virus and produce a candidate vaccine in three to four weeks,” Lomonossoff told the BBC. “It has potential for making vaccines against emerging epidemics, of course recently we had Zika and prior to that we had Ebola.”

Tinkering with plant machinery could also potentially yield other useful results, including clean fuel for our vehicles and compounds to fight diseases.

While Lomonossoff’s unique process provides a cheaper, more efficient way to make vaccines, there are still aspects to work out before its fully implemented; for example, whether using a tobacco plant will lead to a vaccine with nicotine in it, and in turn, create a nicotine craving.

Polio currently affects very few people — 37 cases were reported in 2016 — but the disease is so infectious that even a single case could be disastrous; that one case could lead to 200,000 new cases every year within ten years. What is perhaps scariest about it is those infected may not even be aware of it; its symptoms include a sore throat, headache, or a fever, all of which are fairly common among less dangerous diseases.

The WHO estimates that, thanks to the global push to eradicate polio, more than 16 million people have been saved from paralysis. If there’s a way to eradicate it completely, it’s worth it.