Effectiveness of vaccination against influenza in SkodaAuto Company employees during the influenza season 2000-2001.

The SkodaAuto management evaluated the effectiveness of vaccination within the course of the influenza season, 2000 - 2001. All 23,782 company employees working in the plants at Mladá Boleslav, Vrchlabí, and Kvasiny were enrolled into the study, of which 5,079 (21.3%) agreed to be vaccinated against influenza in the autumn, 2000. In comparison with the preceding years, two- to three-fold more employees were vaccinated. During the study period (i.e. between the 4th and 13h week of 2001), 67 (1.3%) individuals from the vaccinated group and 1,297 (6.9%) from the non-vaccinated group fell ill due to influenza or an influenza-like disease (i.e. a five-fold difference). The morbidity peak appeared in the 5th and 6th calendar week with the number of sick reaching nearly 300 during the latter. The morbidity from acute respiratory disease (ARD) in the district of Mladá Boleslav in calendar week 6 was 484 per 10,000 inhabitants which was nearly twice that of the national average. Overall, influenza-related morbidity in the SkodaAuto Company was 4 to 7 times lower than ARD in the Mladá Boleslav district; whereas the respective values in the vaccinated group were up to 10-fold lower. The vaccination effectiveness reached 81.2%.