The ability of seasonal and pandemic influenza to disrupt military operations

Influenza is one of the few infectious diseases that is able to disrupt military operations quickly. Although the extreme mortality rates seen during the pandemic of 1918-19 when tens of thousands of soldiers died has never been repeated (for as yet unclear reasons), illness rates alone make influenza of great military importance. Seasonal influenza infection rates from 2-30% of a partially immunized force can still limit military activity and challenge the ability of medical facilities to cope with a sudden number of sick soldiers. Although social distancing and antiviral medications may have some role, in military practice the main preventive measure against seasonal and pandemic influenza is annual immunization with a current vaccine chosen to match the viruses then circulating