Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Page 24 Page 25 Page 26 Page 27 Page 28 Page 29 Page 30 Page 31 Page 32 Page 33 Page 34 Page 35 Page 36 Page 37 Page 38 Page 39 Page 40 Page 41 Page 42 Page 43 Page 44 Page 45 Page 46 Page 47 Page 48 Page 49 Page 50 Page 51 Page 52 Page 53 Page 54 Page 55 Page 56 Page 57 Page 58 Page 59 Page 60 Page 61 Page 62 Page 63 Page 64 Page 65 Page 66 Page 67 Page 68 Page 69 Page 70 Page 71 Page 72 Page 73 Page 74 Page 75 Page 76SEPTEMBER 2016 SEEDWORLD.COM / 39 is given as a shot rather than orally, it is more difficult to administer as well. The WHO, recognizing the problems with the oral vaccine, is now recommend- ing that everyone in the world receive a dose of IPV. But the need for boosters remains, particularly in the very young and very old, whose immune systems are not as efficient, Daniell notes. He believes his virus-free vaccine cre- ated by plants, which could be produced relatively inexpensively and does not require refrigeration or special handling, could be an important component in reach- ing the goal of global polio eradication. “We can ship capsules to every corner of the world and boost that IPV inoculation,” he says. “It’s time to improve upon the vaccinations we’ve been using for 75 years.” Using plants to create a vaccine comes with a number of advantages, explains David Rowlands of the University of Leeds’ Faculty of Biological Sciences, who helps lead a separate project which is also using plants to develop a new polio vaccine. The global consortium has been awarded $1.5 million by the WHO to develop a safer polio vaccine, using a new technique developed at the John Innes Centre in the United Kingdom. The University of Leeds-led research project aims to develop ways of making new polio vaccines without using the live virus, and exploring different methods for their production. Although the principle of using plants is well established, no major plant-based vaccine has yet been widely introduced. The goal is to use plants to produce virus- like particles (VLPs), proteins that resem- ble the polio virus but do not actually carry any of its genetic material. “Growing large quantities of VLPs in plants is surprisingly easy and incredibly efficient. You simply introduce bacteria con- taining the genes for the VLP into the plant, which results in the plant’s cells making many copies of the VLP,” says George Lomonossoff of the biological chemistry department at the John Innes Centre. “The process, from introduction of the bacteria to harvesting the VLPs from the crushed leaves, can take just a matter of weeks. The added beauty of this technique is that the risk of contami- nation with other human viruses using this production technique is significantly lower than some other vaccine produc- tion systems.” The two vaccines currently used throughout the world are produced through much different means. The inac- tive vaccine is grown in a type of monkey kidney tissue culture, and the virus is then inactivated with formalin. The oral vaccine is produced by the passage of the virus through non-human cells, which produces spontaneous mutations in the viral genome. “We know that our approaches using plants create stable vaccines that are effective against the virus in the lab. The next stage is to show how they can be manufactured cost effectively on the scale needed to replace the current vac- cines,” Rowlands says. “The fundamental challenge is to build protein shells that are the same as the virus but that do not have any of the genetic material of the virus,” he says. “Until now, the problem with this approach to developing a new polio vac- cine has been that, though we’ve been able to create these empty virus-like particles, they have been significantly less stable than the complete virus and were therefore not suitable for making vaccines.” The U.K. consortium’s research has developed methods of build- ing the genome-free particles for all three types of the virus with the stability needed by the researchers. Like Daniell’s vaccine, the particles will “trick” the body into developing immunity to the polio virus, despite not containing any of the actual virus. In Daniell’s work, the researchers used two different growing systems. One was in the greenhouse at Pennsylvania State’s Pennovation Works campus, a high-tech facility that grows the plant in soil and uses natural light. The second was the Fraunhofer USA facility, which more closely replicates how a commer- cial pharmaceutical production facility would run, using a hydroponic system and artificial lighting. A hydroponic system could also easily be scaled up by adding racks and thus using vertical space, which a traditional greenhouse could not do. The researchers were able to harvest a new batch of pharmaceutical-containing let- tuce every four to six weeks. The End of Polio? There has never been a better time to eradicate polio than now, notes Peter Bloland, acting director of Center for Disease Control’s Global Immunizations Division, Center for Global Health. “With the right political commitment at all levels to improve surveillance and reach unvaccinated children, and with sufficient financial resources and techni- cal support, Afghanistan and Pakistan have an extraordinary opportunity to take the world over the finish line and end polio for good.” According to Steve Oberste, microbiologist in the CDC’s Division of Viral Diseases, National Center for Immunization and Respiratory Diseases, the ability to create a vaccine without using any actual polio virus holds tremen- dous potential. “A vaccine made without infectious virus is safer to produce in a developing country where personnel and other costs are lower and where production is closer to the customer, thus lowering shipment costs,” he says. In fact, the ability to create cheaper vaccines goes far beyond polio. Daniell says the concept of a low-cost booster vaccine could be used for many other viral diseases, too. SW POLIO: THE 5 W’S WHO: Primarily affects children under 5 years of age. WHAT: Polio is a highly infectious disease caused by the poliovirus. It invades the nervous system and can cause total paralysis in a matter of hours. The virus is transmitted person-to-person, spread mainly through the fecal-oral route or, less frequently, by contaminated water or food. WHEN: Polio cases have decreased by more than 99 percent from an estimated 350,000 cases in 1988 to only 74 reported cases in 2015. WHERE: Today, only two countries (Afghanistan and Pakistan) remain polio-endemic, down from more than 125 in 1988. WHY: The reduction is the result of the global effort to eradicate the disease.