Sustainability and Sustainable development have been important topics

2.3.2. Emergy accounting
2.3.3. Emergy indices
The traditional and revised emergy-based indices are involved in vaccination study. At the same time, we designed two new indices “resource use efficiency (RUE) and unit environmental impact (UEI)” based on the methodology in this case to acquire a more comprehensive view on efficiency, environmental pressure and sustainability from input and output perspectives. On the basis of the different calculation approach, two results derived from the traditional and revised indices were calculated and discussed.