Answer: I really don't understand your question but i will answer it my way. To prevent death people need to be healthy and go to the doctors if something is wrong. especially with diseases and cancer.
Explanation:
Iodine is a mineral found in some foods. The body needs iodine to make thyroid hormones. These hormones control the body's metabolism and many other important functions. The body also needs thyroid hormones for proper bone and brain development during pregnancy and infancy
Answer:
Incidence unchanged, prevalence increases.
Explanation:
Disease can be caused by the pathogens like virus, bacteria, fungi and plasmodium. The infection fro the disease also depends on the immunity of the individuals.
Discovery of the drug requires different experiment and observations. The drug that prevents the mortality but not able to cure the disease. This do not change the disease incidence but might not able to the increase in the prevalence of the disease.
Thus, the answer is incidence unchanged, prevalence increases.