Mandatory vaccination of health care workers raises important questions about the limits of a state's power to compel individuals to engage in particular activities in order to protect the public. In justifying New York State's regulations requiring health care workers who have direct contact with patients or who may expose patients to disease to be vaccinated against seasonal and H1N1 influenza, New York State Health Commissioner Richard Daines recently argued, “[O]ur overriding concern . . . as health care workers, should be the interests of our patients, not our own sensibilities about mandates. . . . [T]he welfare of patients is . . . best served by . . . very high rates of staff immunity that can only be achieved with mandatory influenza vaccination — not the 40-50% rates of staff immunization historically achieved with even the most vigorous of voluntary programs. Under voluntary standards, institutional outbreaks occur. . . . Medical literature convincingly demonstrates that high levels of staff immunity confer protection on those patients who cannot be or have not been effectively vaccinated . . . while also allowing the institution to remain more fully staffed.”1