Influenza and Influenza Vaccine

Read the case study on and discuss the following: 

1.  What are the main symptoms of influenza? 
2. Would you expect a flu shot to protect against the stomach flu? Why or why not? 
3. Identify some of the various causative agents of stomach flu and compare them to the influenza virus. 
4. Karen described the upper respiratory infection (URI) that she suffered last year and thinks that her well-being is a matter of fate. How many infectious agents cause URI? How can these infections be prevented? How can they be treated?