The impact of influenza vaccination on respiratory illness at a boarding school.

We studied the impact of influenza vaccine during an outbreak of influenza at a 989-student boarding school in January to March, 1989. By February 6, 120 (17%) of 690 students completing survey questionnaires had been ill with fever and respiratory symptoms. Eighty-seven students had received influenza vaccine in the previous 18 months; these students had an attack rate half that of the unvaccinated students (9% v 19%; vaccine efficacy = 50%, confidence interval = 0%-70%). We estimate that, if the entire student body had been vaccinated, influenza-like illness could have been prevented in 162 students (16% of the school), and that preventing this illness could have avoided at least 482 student-days of missed classes, or approximately one student-day for each 1.8 additional doses of vaccine given. This study suggests that, when feasible, a broad influenza immunization policy for healthy students at residential schools should substantially decrease the disruption of school activities caused by influenza.

Evaluation of the response to xenon-133 radiations by thermoluminescent dosimeters used during the accident at Three Mile Island.

An evaluation is presented of the accuracy and sensitivity of three types of TLD's used during the accident at the Three Mile Island Nuclear Station. This evaluation indicated that, due to the method of calibration, all the dosimeters over-responded to 133Xe radiations. The response ranged from slightly above unity to almost two. Exposures of the TLD's were of two types, namely, the characteristic X-rays either were or were not filtered from the beam. The angular sensitivity of the dosimeters is also reported.