Tobacco Plants Are Key in Containing Ebola Outbreak
A new, experimental plant-based treatment has saved the lives of five infected patients, including two Americans.
The Ebola virus outbreak in West Africa has claimed more than 1,200 lives, the World Health Organization reported Tuesday. As authorities hasten to contain the deadly virus, which kills at least half of those infected, a new plant-based experimental treatment is on their radar after it has helped five infected people—two Americans and three Africans—survive.
The drug ZMapp was administered to two Americans infected with Ebola in West Africa, Ken Brantly and Nancy Writebol, who are currently in an isolation unit at Emory University Hospital. On Friday, their friends and family reported that the two are doing “very well” and are getting stronger every day.
ZMapp was also used to treat three African doctors, who are showing “remarkable signs of improvement” according to Liberia’s information minister, Lewis Brown.
The plant-based approach, which is also known as pharming, produces complex and valuable proteins for medicines. The genetic blueprints for a particular protein is “infiltrated” into a plant, which then produces the proteins to be harvested from plant tissues.
Tobacco plants are preferred by scientists for this method because they grow quickly and their biology is familiar, according to Ben Locwin, a pharmaceutical biotech consultant in Portsmouth, New Hampshire. But proteins can also be produced in other plants such as safflower and potato.
“It’s definitely not something you smoke,” Jean-Luc Martre, spokesman for Medicago, notes. The tobacco plant used for this method is just a relative of the plant used to make cigarettes.
Medicago is a Canadian company that is testing flu vaccines made with tobacco plants. It is awaiting the approval of federal authorities before it can utilize its new production facility in Research Triangle Park, N.C.
The facility, which can handle about 90,000 plants, is expected to be able to make 30 million doses of seasonal flu vaccine a year, or 120 million vaccine doses to fight a major outbreak of pandemic flu.
The benefits of plant-made vaccines include lower cost of production, according to Locwin, who said it has a “tremendous amount of promise.”
The plant-based approach to obtaining complex proteins is more popular than ever, in the context of the Ebola outbreak and the threat of bioterrorism. It is a “fast and cheap” method of producing a lot of vaccine material, explains Daniel Tuse, a consultant and managing director of Intrusept Biomedicine. If a new germ produces a threat, its genetic material can be inserted into large numbers of plants, which will churn out material for vaccines.
You can start making a protein within a matter of days, according to Robert L. Erwin, president of iBio, but tobacco plants must be grown for about a month before they can be infected with the protein’s genetic material, and the proteins are harvested and purified.
The federal government, specifically the Defense Department, is funding research on quickly producing proteins in tobacco plants to produce these vaccines.