A tablet-based Influenza Vaccine Post-Introduction Evaluation (IPIE) tool was developed by MMGH jointly with WHO, the U.S. Centers for Disease Control and Prevention (CDC) and the Swiss Tropical and Public Health Institute to provide a systematic approach to assess the influenza vaccine implementation process. The tool was used in Belarus, Morocco and Thailand. Data from the three middle-income countries highlighted critical factors related to health workers as a target group and as key influencers; unique challenges for acceptance of the vaccine in pregnant women; and the need for strengthening adverse events reporting and of potential vaccine hesitancy. The assessments led to improvements in the countries’ influenza vaccination programmes.