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BackgroundPolished rice is a staple food for over 50% of the world's population, but contains little bioavailable iron (Fe) to meet human needs. Thus, biofortifying the rice grain with novel promoters or enhancers of Fe utilization would be one of the most effective strategies to prevent the high prevalence of Fe deficiency and iron deficiency anemia in the developing world.Methodology/principal findingsWe transformed an elite rice line cultivated in Southern China with the rice nicotianamine synthase gene (OsNAS1) fused to a rice glutelin promoter. Endosperm overexpression of OsNAS1 resulted in a significant increase in nicotianamine (NA) concentrations in both unpolished and polished grain. Bioavailability of Fe from the high NA grain, as measured by ferritin synthesis in an in vitro Caco-2 cell model that simulates the human digestive system, was twice as much as that of the control line. When added at 1:1 molar ratio to ferrous Fe in the cell system, NA was twice as effective when compared to ascorbic acid (one of the most potent known enhancers of Fe bioavailability) in promoting more ferritin synthesis.ConclusionsOur data demonstrated that NA is a novel and effective promoter of iron utilization. Biofortifying polished rice with this compound has great potential in combating global human iron deficiency in people dependent on rice for their sustenance.

In 2004 an Institute of Medicine report warned of vaccine shortages, raising concerns about disease outbreaks. More than a decade later, we looked for progress in reducing vaccine shortages. We analyzed data on vaccine sales and shortages reported by practitioners and patients to the Food and Drug Administration and the American Society of Health-System Pharmacists in the period 2004-13. We found that the number of annual vaccine shortages peaked in 2007, when there were shortages of seven vaccines; there were only two shortages in 2013. There were no shortages of vaccines with a mean price per dose greater than $75 during the study period. Furthermore, we found that a 10 percent increase in price was associated with a nearly 1 percent decrease in the probability of a shortage. Government payers should carefully consider the benefits of averting shortages when evaluating prices for vaccines, including older vaccines whose prices have been subject to congressional price caps. [ABSTRACT FROM AUTHOR]