Immunity of hospital personnel against polio virus

Sera from 275 employees of three hospitals were tested for the presence of antibodies to polio virus. Immunity was found to increase with age, and was higher in personnel directly involved in patient care than in the others. Previous exposure to poliomyelitis as well as a history of previous immunization did not correlate with the immunological status of the employee. When antibodies against one of the three polio types or more could not be demonstrated, the employee was vaccinated by an inactivated polio virus vaccine.