In 2011, institutional requirements for pertussis vaccination of healthcare personnel were reported by nearly one-third of surveyed US hospitals. Requirements often applied to personnel with certain clinical responsibilities, such as those caring for infants. Healthcare personnel who were not on an institution's payroll were rarely subject to pertussis vaccination requirements.

US health professional schools with student immunity requirements for recommended vaccines frequently accept evidence of immunity other than vaccination but vary widely on the types of evidence that are accepted. Exemptions for nonmedical reasons and, to a lesser extent, medical reasons are often obtainable by a student-written document.

We surveyed program coordinators at 106 hospitals and health departments that participated in the National Smallpox Vaccination Program to ascertain how program-level factors affected the rate of smallpox vaccine uptake by staff. In a fully adjusted multivariate model, health departments achieved significantly higher vaccination rates than did hospitals, as did facilities that invited fewer employees to be vaccinated.