Which of the following adverse reactions is an altered physiological state produced by repeated administration of a drug which necessitates the continued presence of the drug to maintain physiological equilibrium? A: Idiosyncratic reaction B: Residual effects C: Drug dependence D: Rebound reaction E: Drug allergic reaction

The main purpose of the text is to_____________. A: convince the reader that vaccines are not as safe as many think B: educate the reader on how vaccines are used and some of their dangers C: educate the reader on the circumstances that would necessitates widespread vaccinations D: present the method by which vaccines are used through the case of the smallpox vaccine