Evaluating to Better Protect Children: Strengthening Evidence on Immunization Impact

Despite global commitments to universal vaccination, nearly 14 million children worldwide still receive no routine vaccines, leaving them completely unprotected against preventable diseases. This injustice is particularly severe in areas affected by armed conflict and repeated shocks, where zero-dose coverage gaps are the widest – and where instability continues to grow globally. Reaching these children is therefore not only a public health priority but also an urgent equity issue that goes far beyond the scope of any single organization. 

Immunization at the Yirimadio health center

In response to this challenge, Muso launched its immunization initiative in May 2023 in Mali and in July 2023 in Côte d’Ivoire, working closely with public health systems to proactively identify and reach zero-dose children in the most underserved communities. The results are promising: the proportion of zero-dose children aged 0 to 23 months has dropped from 10% to under 1% within the first 24 months of implementation, and this improvement has remained consistent over time. As of January 2026, 83.50% of children in the communities we serve were fully vaccinated and up to date on their vaccination schedule.

To rigorously assess the impact of this work, Muso is conducting an interrupted time series analysis study to compare the change in vaccine coverage at Muso-supported sites with trends across all other districts in Mali and Côte d’Ivoire. 

As part of this evaluation, Muso and national partners are working together to validate and strengthen the underlying data to ensure accuracy and comparability. In December, Muso partnered with Mali’s National Immunization Center and National Institute of Public Health to conduct a technical workshop to validate the national immunization data. This workshop marked a critical milestone in the evaluation of Muso’s immunization initiative. 

The initiative focuses on underserved communities where children are most at risk of missing routine vaccinations. Through proactive, community-based outreach led by Professional Community Health Workers (proCHWs) and other frontline healthcare providers, the program identifies zero-dose and under-vaccinated children and connects them to timely immunization services, with support from trusted community leaders. 

The December workshop ensured that the data used to measure impact are robust, comparable, and credible. Led by Muso’s Research team, participants analyzed routine data from the national health information system collected before and after implementation. This enabled partners to assess changes in immunization coverage over time across several intervention areas, including Bankass, Yirimadio, and Bakorobabougou. 

Over five days, participants jointly extracted and validated vaccination data, calculated coverage rates by district, vaccine type, and age group, and cross-checked results against health facility records and population estimates. Common data quality challenges – such as missing values, inconsistencies, and unusually high coverage rates–were systematically identified and corrected. The result is a clean, validated dataset ready for impact analysis – starting with interim analysis now and final analysis scheduled in two years time. 

This workshop represents an important step in improving the quality of national immunization data and advancing the rigorous evaluation of Muso’s efforts to promote equitable access to immunization. By grounding its work in robust data and close collaboration with national institutions, Muso and its partners reaffirm their commitment to evidence-based health policies in service of community health.