The macro-epidemiology of influenza vaccination in 56 countries, 1997--2003.

The WHO Global Agenda on Influenza calls for measuring the progress of national influenza vaccination programs. In response, the Macro-epidemiology of Influenza Vaccination (MIV) Study Group has gathered information on influenza vaccination in 56 countries. During the period 1997--2003, influenza vaccine distribution increased considerably in almost all countries. In 2003, the countries with the highest levels of vaccination (doses distributed/1000 population) were Canada (344), the Republic of Korea (311), the United States (286) and Japan (230). Most countries recommended influenza vaccination for elderly persons and those with high-risk medical conditions, including immuno-compromise. Fewer countries provided public reimbursement for vaccination through national or social health insurance. Higher levels of vaccination were not closely related to higher levels of economic development, but in many instances public reimbursement for vaccination seemed to be associated with greater vaccine use. From 1994 to 2003, the global use of influenza vaccines increased more than two-fold. In 2003, the 56 MIV Study Group countries accounted for approximately 95% of the 292 million doses of influenza vaccine distributed worldwide, and 62% of these doses were distributed within nine vaccine-producing countries in North America, Western Europe, Japan and Australia. However, influenza vaccination was increasing rapidly in many non vaccine-producing countries, and this change has important implications for pandemic vaccination.