Rice is a plant that can be stored at room temperature for a long time, which is very important for the development of the vaccine. It's estimated that worldwide, it costs $200 to $300 million each year to preserve vaccines at cold temperatures, explains Nochi. "Thus we termed our technology cold-chain-free vaccine. In addition, purification of the vaccine antigen from rice seed is not necessary, also causing a reduction in cost."

Furthermore, abolishing the painful use of needles and syringes not only cuts costs, but also prevents pathogens from accidentally appearing in the vaccines and then spreading throughout the population, especially in underdeveloped countries where supplies are limited.

The researchers plan to prepare the rice-based vaccine in the form of a capsule or tablet for applications in humans, hence they don't have plans to deliver the vaccine as a form of steamed rice. The rice-based vaccine is also suitable for prevention of other mucosal infectious diseases, such as influenza and HIV.

"Genetically altering plants for vaccinations is an important area of research, and the work being done by the Japanese researchers is very exciting," says Carol Tacket, a professor of medicine at the Center for Vaccine Development at the University of Maryland School of Medicine. "Using plants to express vaccines is technically achievable, and the main barrier is identifying protective antigens--in other words, what proteins will protect when used as vaccines. It's really identifying the right antigen to put in expressions."