In 2009, WHO recommended universal rotavirus vaccination coverage. Despite this push, many countries have not fully integrated it into their vaccinate schedule. GAVI aims to provide support to at least 30 countries by 2015. However the demand for the vaccine remains high and it is not often reaching children in most need. While marginalized and low-income children benefit the most from coverage, the distribution is often inequitable. Children from wealthier quintiles are often more likely to have the highest rates of vaccination despite the lowest risk of mortality (Rheingans, Atherly, & Anderson, 2012).

Another recent issue is assessing the efficacy and safety of the rotavirus vaccine. Despite its remarkable success, the vaccine's full impact has yet to be realized. Its use in developing countries, where morbidity and mortality due to rotavirus are greatest, has been limited thus far. With the burden of diarrheal disease being the greatest in these countries, more work is required to understand the reasons for variance in efficacy and to identify ways to improve the vaccine's performance.

In their literature review, Patel et al. draw the conclusion that since country-wide rollouts of rotavirus vaccine in many low-middle and high-income countries, child mortality due to diarrhea have significantly dropped (2011). There is less evidence concerning the vaccine's effectiveness in low-income and developing countries, though studies suggest its impact is greatest in the poorest settings (Patel et at., 2011). Most recently, in a 2014 study of Indian infants, the rotavirus vaccine's efficacy against severe rotavirus gastroenteritis was over 50% (Bhandari et al., 2014).

One of the main controversies pertaining to the rotavirus vaccine is its potential impact on postvaccination strain changes; that is, that vaccination rollout will lead to the spread of more severe strains of the virus. However, the vaccine is shown to be effective against the strains that result in the most hospitalizations (Patel et al, 2011).A second debate concerning this vaccine is its correlation with intussusception post-vaccination- a severe condition in which one portion of the bowel slides into another section of the intestines. In a recent study based in the United States, Weintraub et al. concluded that there was a significant increase in rate of intussusception after rotavirus vaccination, "a risk that must be weighed against the benefits of preventing rotavirus-associated illness," (2014).

Using antibiotics to treat diarrhea is a common challenge regarding treatment. As the IMCI training module on diarrhea mentions, antibiotics are ineffective in treating most diarrhea. Antibiotics are the recommended course of action when a child has dysentery or if a child has severe dehydration in cholera areas, but they are generally inappropriate for treating other diarrheas. In fact, antibiotics have the potential to exacerbate the child's illness and to contribute to global antibiotic resistance. Finally, unnecessary antibiotic use is a waste of resources, especially problematic in resource-strained settings (Chedid et al., 2014).

A final challenge to treating diarrhea with ORS is the lack of clean water available to make the solution. As previously mentioned, 780,000,000 live without access to a clean water source. Not only are these individuals especially vulnerable to diarrhea, but they are often the least well-equipped to treat it. Without clean water sources, it becomes especially difficult to make ORS. Implementing financially feasible and effective means of water sanitation in developing and low resource countries is an ongoing debate.