If older bucks have higher CWD prevalence and move the disease around more, why use earn-a-buck?
While earn-a-buck regulations (where a hunter must harvest an antlerless deer prior to harvesting an antlered deer) are not the perfect season structure for managing CWD since the restriction tends to save mature bucks to some degree, it is the most effective tool available for lowering deer populations and thus reducing disease spread.
Although unlimited, either sex seasons are, in theory, a better tool for managing CWD, history has shown that when such seasons have been implemented, such as in 2006, antlerless harvest has dropped significantly. As a result, the populations have tended to subsequently increase.
Other possible management options and season structures are continuously being explored.