An adult with fever, cough, myalgia, and headache could have been prevented by which vaccine?

• A. Pneumococcal vaccine
• B. Influenza vaccine
• C. Measles vaccine
• D. Hepatitis B vaccine

Answer: (B)

Protecting against influenza is the key idea here. The flu vaccine targets seasonal influenza, which in adults typically presents with fever, cough, myalgias, and headaches. Getting the influenza vaccine reduces the risk of contracting influenza and its respiratory symptoms, making it the best match for this presentation. The pneumococcal vaccine prevents pneumococcal pneumonia and other invasive pneumococcal diseases, not the flu-like syndrome described. The measles vaccine prevents measles, which starts with fever, cough, coryza, and conjunctivitis followed by a rash, not the influenza picture. The hepatitis B vaccine prevents hepatitis B, a liver infection, not respiratory symptoms. So the influenza vaccine best explains prevention of this illness. (Note: vaccines reduce risk but don’t guarantee protection.)