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How to grow an Ebola vaccine with a tobacco plant

November 23, 2015 at 6:30 PM EDT
What looks like an ordinary greenhouse is actually an around-the-clock Ebola vaccine factory. At a facility in Kentucky, plants are being injected with a protein in order to spur them into producing one of the three antibodies used in the experimental drug ZMapp. Special correspondent Mary Jo Brooks reports on how bio-pharming is helping to ramp up the speed of drug production to fight the disease.
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GWEN IFILL: we turn to the search for a treatment for Ebola.

West Africa is still dealing with the aftermath of the worst outbreak of the disease in recorded history. Last week, Liberia reported a handful of new cases, just months after the World Health Organization said the country was free of the disease.

And this weekend, not one, but two panels said the WHO needs to substantially reform and change the way it deals with international health crises.

Special correspondent Mary Jo Brooks has a report on the hunt to finally stop the virus.

MARY JO BROOKS: It looks like an ordinary greenhouse filled with plants basking under light, but at this facility just outside Owensboro, Kentucky, the plants themselves have become a labor force, working around the clock to manufacture a cure for Ebola.

HUGH HAYDON, CEO, Kentucky Bioprocessing: These plants are 27 days old.

MARY JO BROOKS: Three days earlier, these plants were injected with a genetic blueprint for one of three antibodies used in the experimental drug ZMapp.

Hugh Haydon of Kentucky Bioprocessing explains how it works.

HUGH HAYDON: The plant recognizes that gene and its machinery turns on and it starts to manufacture that protein for us. And it’s really that simple. It becomes a little bitty factory.

MARY JO BROOKS: ZMapp was still in the developmental stage when Ebola first broke out in West Africa in March of 2014. The disease has since claimed more than 10,000 victims. But a handful of people were successfully tweeted with ZMapp, including Dr. Kent Brantly.

DR. KENT BRANTLY, Ebola Survivor: Today is a miraculous day. I am thrilled to be alive, to be well and to be reunited with my family.

MARY JO BROOKS: Since then, the drug has being undergoing clinical trials in West Africa and the FDA has granted it fast-track approval status.

Larry Zeitlin and Kevin Whaley are the scientists from San Diego who developed the ZMapp antibodies, which were designed to quickly attack the Ebola virus.

KEVIN WHALEY, Inventor of ZMapp: In a vaccine, you give a person a protein that stimulates your own body to make antibodies. In this case, we’re giving antibodies directly to you, so your body doesn’t have to make them.

LARRY ZEITLIN, Inventor of ZMapp: And unlike the vaccine, where it takes you weeks to months to build up protective immunity, as soon as the antibodies are provided to the patients, they’re protected against that disease.

MARY JO BROOKS: Speed is the name of the game in fighting infectious disease. And it is the reason that Whaley and Zeitlin decided to manufacture their drug using plants, rather than the traditional animal protein method.

They chose an Australian relative the American tobacco plant in a process that is quick and relatively simple. Just three weeks after the seeds go into the soil, the plants are mature enough to be dipped into a liquid which contains proteins to be replicated.

The plants grow those proteins for another week, and then are harvested and chopped up. The resulting green liquid is filtered and tested and, by day 40, it’s ready to be shipped out.

HUGH HAYDON: It’s a very fast system. And if it’s faster, it costs a little bit less on the front end particularly. It gives you a lot of flexibility in terms of developing a product.

You get your protein. You look at your protein. Is it what you wanted? If it doesn’t have the exact characteristics that you want, you do it again. You reengineer it and do it again until you get exactly where you want to be.

MARY JO BROOKS: The system of biofarming could be useful for a number of drug therapies that must ramp up production quickly. The Canadian company Medicago uses tobacco plants to manufacture flu vaccine, which needs to change seasonally.

At its large greenhouse in Raleigh-Durham, North Carolina, workers and robots tend to the growing plants.

DR. MICHAEL SCHUNK, Vice President of Operations, Medicago: They produce the vaccine over about a week.

MARY JO BROOKS: So it’s a very quick, efficient process.

DR. MICHAEL SCHUNK: It’s very quick, very efficient, very adaptable.

MARY JO BROOKS: Michael Schunk is the vice president of operations.

DR. MICHAEL SCHUNK: This plant technology can respond in about half the time of the traditional flu manufacturing technologies, so that’s what started us into the flu, and we have just continued to grow with that.

MARY JO BROOKS: Medicago is in the final stage of clinical trials to receive FDA approval for its flu vaccine. Once granted, the company says it will be able to make 30 million doses a year. It has also begun producing an Ebola drug similar to ZMapp.

Both Medicago and Kentucky Bioprocessing received Defense Department money to develop their pharmaceuticals. The hope is that the technology could be used to quickly counter a pandemic or bioterrorism attack.

DR. MICHAEL SCHUNK: This facility is about 27,000 square feet.

MARY JO BROOKS: But Michael Schunk says the technology holds promise for all kinds of drugs. He’s especially optimistic that developing nations will use this method to manufacture vaccines on their own soil, since the cost of building the facilities is much less than traditional drug factories.

DR. MICHAEL SCHUNK: This is not a very complicated technology. It’s certainly transportable. Every country has greenhouses, so every country has the potential to have a facility that can be used to produce vaccines that maybe are more a concern to that particular country.

MARY JO BROOKS: Schunk and other biofarming proponents predict that soon drugs to treat herpes, HIV, MRSA, and other infectious diseases will routinely be grown in plants. Of course, the irony of using a version of tobacco to save lives is not lost on anyone, including Hugh Haydon.

HUGH HAYDON: There is some irony. There is no question about that.

But what our business is about and what we have — what we have always been about is using the plant to create things and to do positive things. Our focus has been biopharmaceuticals and using the plant to yield those kind of proteins. And it works really well for that.

MARY JO BROOKS: Biopharmaceuticals, plants that one day could be used routinely to wipe out infectious diseases.

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