Measles and influenza are two diseases that are caused by different viruses. The influenza virus has evolved into many different strains over time, while the measles virus has changed very little. There are vaccines for both influenza and measles, which are used to control the spread of these two diseases. Which of the following statements likely describes the effectiveness of these two vaccines?

A.
The measles vaccine is more effective than the influenza vaccine.
B.
The measles vaccine and the influenza vaccine are both ineffective.
C.
The influenza vaccine is more effective than the measles vaccine.
D.
The measles vaccine and the influenza vaccine are equally effective.