The Upstate Global Health Institute is currently seeking healthy participants 18-55 for a dengue fever clinical trial. Dengue fever is a mosquito-borne illness caused by a virus that impacts an estimated 100 million people each year. A certain type of mosquito transmits the virus. When a mosquito carrying dengue virus bites someone, he or she can get sick with a dengue infection. These infections can be very mild, with little or no symptoms, but may cause fevers, severe headache, nausea, vomiting, muscle and joint pains, pain behind the eyes, and skin rash. An antiviral medication against Dengue has been developed, which is an experimental new drug that is being studied to prevent and treat dengue illness. The goal of this study is to see how well the drug works to prevent or treat dengue infection and to observe the effectiveness of the drug.