Suppose you have a choice between two preventative medicine programs. One is a one-time vaccination program with total costs of $160,000 per 1000 patients that occur immediately, that on average reduces medical costs by $550,000 per 1000 patients in 20 years. The other is a three-year program, with costs of $55,000 per year per 1000 patients, that reduces medical costs by $600,000 per 1000 patients in 15 years. Determine the NPV of each program (per 1000 patients) using a discount rate of 5%. Which program is the better choice? Is the choice of program sensitive to the discount rate? Is there a discount rate at which neither of the programs has a positive net present value? If so, explain why. If not, why not.