Supporting immunization programs with improved vaccine cold chain information systems

Immunization is recognized as one of the most successful public health interventions ever devised. A critical component of immunization programs is the vaccine cold chain - the cold storage to keep vaccines safe from manufacture to eventual delivery to the child. Countries need to manage their vaccine cold chains and logistics systems to ensure sufficient storage capacity, distribution of adequate supplies of vaccines, and functional cold storage equipment. There are particular challenges for remote facilities where transportation costs are high, power infrastructure is lacking, and communication is limited. Accurate information about the cold chain is essential to address these challenges and to evaluate the impact of different interventions. A Cold Chain Information System (CCIS), which tracks health facility information and the country's cold chain equipment can help address these challenges at both the strategic (planning) and tactical (management) levels. This paper describes our efforts to develop a CCIS for Laos, in collaboration with UNICEF and the Lao Ministry of Health. The work builds on experience with deploying CCIS's in multiple countries along with developing analysis tools and data standards. The CCIS in Laos uses DHIS2, a widely used web based health indicator system as the back end, which is integrated with SMS reporting from the district and health center level where internet is not guaranteed to be available. A central goal of the system is to allow regular reporting of vaccine stock levels and vaccine refrigerator status (measured by logging devices recording high and low temperature alarms). The system is designed with notifications to promote action by technicians or managers. The technical contributions of this work include the development of a new data model for DHIS2 and a text message system using an Android gateway to RapidSMS with a custom notification engine interfacing to DHIS2.