Officials and professional societies treat influenza as a major public health threat for which the annual vaccine offers a safe and effective solution. In this article, I challenge these basic assumptions. I show that there is no good evidence that vaccines reduce serious complications of influenza, the outcomes the policy is meant to address. Moreover, promotional messages conflate "influenza" (disease caused by influenza viruses) with "flu" (a syndrome with many causes, of which influenza viruses appear to be a minor contributor). This lack of precision causes physicians and potential vaccine recipients to have unrealistic assumptions about the vaccine's potential benefit, and impedes dissemination of the evidence on nonpharmaceutical interventions against respiratory diseases. In addition, there are potential vaccine-related harms, as unexpected and serious adverse effects of influenza vaccines have occurred. I argue that decisions surrounding influenza vaccines need to include a discussion of these risks and benefits.