Immunization campaigns and political agendas: retrospective from Ecuador and El Salvador.

Since the mid-1980s international donors have promoted vertical, campaign-based strategies to help improve immunization coverage in poor countries. National immunization days (NIDs) are currently in vogue and are prominent in the worldwide polio eradication efforts. In spite of their widespread use, campaigns that include NIDs have not been well evaluated for their effects on coverage, reduction in vaccine-preventable diseases, or effects on the health system. An assessment of the results of two such campaigns implemented in Ecuador and El Salvador shows limited impact on short-term coverage and questionable effects on long-term coverage and disease incidence. Although NIDs may have substantial short-term political benefits, the vertical approach can undermine provision of routine services by ministries of health and may be counterproductive in the long-term.