Before revision:  In this case, the optimal control must meet two competing requirements: First, the minimization of disease-related deaths, and, second, the establishment of a sufficient degree of herd immunity at the end of the measures, in order to exclude a second wave.
After revision:  In this case, the optimal control must meet competing requirements: First, the minimization of disease-related deaths, and, second, the establishment of a sufficient degree of herd immunity at the end of the measures, in order to exclude a second wave.