The Following Questions Refer to the Description Below

question 60

Multiple Choice

The following questions refer to the description below.
Malaria is a global health problem in over 100 countries, killing about one million people every year. The protist, Plasmodium, that causes malaria lives in 2 hosts, mosquitoes and humans. Malaria is transmitted to humans by the Anopholes mosquito.
-The use of DDT greatly decreased numbers of Anopholes mosquitoes in the 1960s, and drugs killed the Plasmodium. Now doctors tend to prescribe a combination of drugs against malaria. Why don't doctors prescribe a vaccine to combat malaria?

• A)In the presence of multiple drugs, the mutation rate of pathogens decreases.
• B)Multiple drugs enhance the immune system better than vaccines.
• C)Making an effective vaccine has proved to be difficult because Plasmodium lives inside the host's cells and continually changes its surface proteins.
• D)There are fewer side effects associated with using a combination of drugs compared with using a vaccine.
• E)Vaccines are more expensive than many drugs.