Vaccination policies in the military: an insight on influenza.

Influenza, despite its generally benign clinical course, is accompanied by absenteeism from work, acute suffering and even mortality, mainly in the elderly and in subjects who have high-risk medical conditions. Its prevention consists of strain specific vaccination, which must be repeated annually due to the high antigenic variability of the influenza virus. Influenza may represent an important obstacle to military readiness, particularly when considering its infectivity within closed communities. Despite such epidemiological situations, influenza vaccination is seldom included in the compulsory vaccination programme of the military on a global level. This may be due to several reasons, namely, a lack of confidence in the vaccine's effectiveness, the need for annual administrations (with expansion of economic and organisational efforts), false assumption that influenza is a disease with a minor impact, contradictory results of cost-effectiveness analyses (examples of which have yet to be made specifically for the military environment). The availability of more effective, economic and easy to administer vaccines, together with detailed and tailored cost-effectiveness analyses, may have a beneficial effect on the role the military plays in the fight against influenza across the globe.