Influenza vaccination in healthy working adults in Russia: observational study of effectiveness and return on investment for the employer.

BACKGROUND All age groups are affected by influenza infection, resulting in significant medical and economic burden. Influenza infection of healthy working adults can have a marked effect on companies due to lost work days and reduced productivity. Studies in corporate settings have shown that vaccination programmes reduce this burden, although there is a lack of data in Eastern European countries. OBJECTIVES To determine the effectiveness of influenza vaccination in healthy working adults in Russia and the economic benefits of such a programme from an employer's perspective. METHODS In a prospective, non-randomized, non-placebo-controlled, observational study, healthy vaccinated and unvaccinated adults employed at the Russian Railways Public Corporation were followed for 8 months during the 2005-6 influenza season using questionnaires. A first questionnaire was administered at inclusion to collect general employee information; a second questionnaire was administered to collect data on post-vaccination adverse events; and monthly questionnaires were used to gather data on influenza-like illness (ILI). Effectiveness calculations and cost analyses were performed to evaluate the impact of the influenza vaccination programme on employee productivity and costs for the employer. The study vaccine used was the trivalent, inactivated, split vaccine Vaxigrip® (sanofi pasteur, France). RESULTS A total of 1331 employees volunteered for the study: 701 were vaccinated and 630 were not. The vaccine effectiveness was 70.4% against ILI events and 80.8% against sick leave days. Assuming that employees working with ILI symptoms had a reduced level of productivity (30-70% of normal), cost savings per vaccinated employee ranged from &U20AC;2.13 to &U20AC;5.43. CONCLUSIONS This study showed that an influenza vaccination programme significantly reduced ILI episodes and absenteeism, and may provide a positive return on investment for the employer.