Vaccination Coverage Quality Indicators (VCQI): a flexible open-source tool for survey data analysis

The World Health Organization (WHO) and Pan American Health Organization (PAHO) make statistical software scripts freely available to conduct standardized analysis of vaccination coverage surveys. The software and accompanying documentation are named the Vaccination Coverage Quality Indicators (VCQI). The software examines data from child vaccination records and caregiver recall to calculate indicators of vaccination access, coverage, continuity, and quality. VCQI produces output tables and figures that may be copied directly into reports and presentations, as well as survey response data sets augmented with child-level outcome indicator variables calculated according to WHO guidance. It can analyze data from routine immunization surveys, post-campaign coverage surveys, and maternal tetanus coverage surveys. VCQI may be used for either the primary analysis of data from new surveys or secondary analysis of earlier surveys. It can analyze data from USAID Demographic and Health Surveys, UNICEF Multiple-Indicator Cluster Surveys, or WHO Expanded Programme on Immunization surveys. Future versions of VCQI may be extended to analyze data from electronic immunization registries. VCQI has been available as a set of Stata scripts since 2015, and as of 2025, the core routine immunization indicators are also available as a new R package named vcqiR. To publicize VCQI's features and capabilities and to celebrate the milestone of R package availability, the authors share this special report to describe the VCQI vision and design, discuss analyses and insights available from it, and map our vision of what the future may hold for flexible standardized analysis of vaccination coverage data.